Exploring How the First Galaxies and Black Holes Took Shape
Surveying Distant Galaxies to Understand Star Formation and Black Hole Growth in the Early Universe
Photographing the Moon with Your Mobile Phone
How to Get the Best Results Without Fancy Gear
The Hunt for Habitable Planets Around Our Nearest Neighbours
Our Sun
Exploring the Heart of Our Solar System
In fiction, they have been universe. In song, they’ve psych-poppers alike. In as spectacular, offering lights that put even the stage
been used as a gateway to a parallel they’ve inspired prog rockers and Welsh
In real life, the northern lights are just an unforgettable display of colourful stage shows of French electro legend Jean Michel Jarre to shame.
James Walsh & Peter Kimpton
Lousie Kaestner
Editor Matt Woods
Designer Contributors Hannah Archer, Terry Edmett, Paul Fisher, Ella Groom, Roger Groom, Mary Hughs Lousie Kaestner, Julie Matthews, Harry Murari, Jodie Sims, and John Tuffin
Greetings, Earthlings!
I’ve taken note of the sidereal time. We are a year and a half behind. It’s time to set the right ascension on the Perth Observatory Newsletter as we deal with its resurrection. As for its declination, that is up to contributors to help work out. Anyway, enough astrograph and ancient astronomer speak.
It’s been a year and a half since our last issue of Galaxia in May 2024. Perth Observatory and the Perth Observatory Volunteer Group have gone through a multitude of changes as they evolve, including a name reversion back to the Perth Observatory Newsletter. Since the last issue, Perth Observatory finished the Millenium Dome, built a new solar dome near the viewing area, began using the Astrograph regularly for Night Sky and Exclusive Night Tours, upgraded the Government Astronomer’s room to include a tablet and installed portable chemical toilets near the viewing area. As for offerings, we still offer the incredible amount of night and day tours and have added a craft collaboration from Supernova Studio on Sundays every fortnight. To say that we’ve been busy is an understatement. If you were to compare the progress Perth Observatory made in the last year to distance travelled from Earth, I’m sure we’ve reached Proxima Centauri.
Recently, Perth Observatory welcomed a new STEM Outreach Officer Jo Ludlow. Her passion for STEM started early and has only grown stronger over time. She says, “I’ve always loved being part of encouraging kids to have fun with science,” With a passion for science and education (she proudly refers to herself as a (“sci-fi geek”), Jo brings not just knowledge, but real lived experience, compassion and a natural gift for connecting with people of all ages. Jo ensures that Perth Observatory remains committed to planting the seeds of space science in the minds of the next generation.
We have an exciting issue for you to read. There are some subtle, and maybe not so subtle, changes to the layout. For instance, we will feature some regular spots such as volunteer shout-outs, volunteer interviews, what’s in the skies, a blast from the past, histrionic history and even competitions with prizes. There will still be the delightful array of ad hoc articles from our passionate and dedicated astronomers and their families.
Please send through your submissions for the next issue to lcmckwd@gmail.com. We accept all forms of prose for the newsletter from volunteers, their families and readers if it is about either astronomy or Perth Observatory and its Volunteer Group.
Louise Kaestner Editor
Halloween Night Sky Tour
Time: 8 pm (Doors open at 7:30 pm)
Price: $55 per adult, $45 per concession and $35 per child
Get on your broomstick and head up to the Perth Observatory for an amazing night. The Observatory will be decorated and the volunteers in costume for this special night. We’ll also be giving out great prizes for the best dressed.
Astronomy 102 Course
Time: 7 pm - 8:30 pm
Price: $300 per person
Are you fascinated by the vast expanse of space and the mysteries of our universe, and want to learn more about it? Well, now is the perfect opportunity to discover more about our amazing cosmos!
Each week of this 5 week course, we’ll delve deeper into a different aspect of the universe, and you’ll be able to use the telescopes.
Paint and Sip
Time: 6:30 pm - 9:30 pm
Price: $120 per person
Let’s get creative and enjoy a Glow in the dark paint and sip experience and viewing through the telescopes.
Run by Ilanit Vanu. You’ll start the evening with a bubbly glass of wine and a grazing plate. Then you’ll start to paint our glow in the dark colourful “Dancing in the moon light” painting. Easy to follow step by step guide.
Astrophotography Workshop
Time: 1 pm - 10 pm (Doors open at 12:30 pm)
Price: $280 per person
Want to get started in astrophotography? We’re running a workshop where you’ll learn to use your camera and a telescope. You’ll also learn what your equipment is capable of so you can try your hand at nightscapes and deep-sky photography.
It’s a fantastic full day of astrophotography that gives you a small group experience learning.
Dr Who Night Tour
Time: 8:30 pm (Doors open at 8 pm)
Price: Adult: $55
Concession: $40
Child (Ages 5 to 17): $30
Celebrate everything Doctor Who on Tardis Day as we celebrate the anniversary of the debut episode of Doctor Who. Come dressed up as your favourite Doctor Who charactor on our night tour to go into the running for best dressed prizes and look at the amazing night sky our our telescopes.
Geminids Meteor Shower Night
Time: 10 pm (Doors open at 9:30 pm)
Price: Adult: $30
Concession: $25
Child (Ages 5 to 17): $20
Experience the Southern Hemisphere’s best meteor shower of the year at the Perth Observatory. Rug up, bring your camera and outdoor chairs or even a bean bag and enjoy watching the last few seconds of hundreds of meteor’s lives before it meets its fiery end in our amazing southern sky.
Breath Beneath the Stars
Time: 7 pm - 9 pm
Price: $85 per person
Enjoy an evening of stargazing, gentle breathwork, and sound healing under a starlit sky at the Perth Observatory.
As the sun sets, you will be guided through a 60-minute gentle breathwork session while gazing upon the emerging stars and nebulas above.
Wearing multi-dimensional sound headsets, you will be immersed in a soundtrack inspired by the worlds of science fiction.
New Year’s Eve Night Tour
Time: 8:30 pm (Doors open at 8 pm)
Price: Adult: $55
Concession: $40
Child (Ages 5 to 17): $30
Looking for something different to do to farewell the year? Then come along to a prefireworks night tour at the Perth Observatory. Our telescope operators will be ready to show you stunning objects whether it’s a single star or a massive nebula. Then to welcome the New Year, you can drive to one of the Perth Hills many lookouts and take in all the fireworks from around Perth at the stroke of midnight.
October Sky tells the story of Homer Hickam, a boy inspired by the launch of Sputnik, the world’s first artificial satellite. That launch in 1957 wasn’t just a Cold War milestone; it was the spark of the space age. A metallic sphere, no bigger than a beach ball, started orbiting Earth and suddenly humanity had reached beyond its cradle. In the film, Homer watches Sputnik streak across the sky, and something lights up in him. It is a belief that the sky is no longer the limit. This sparked an interest in STEM and, ultimately, rocket building.
I often think of that scene when I’m outside with my telescope, trying to catch a glimpse of the International Space Station. Satellites are no longer novelties; they’re tools woven into every part of our lives—GPS, weather forecasting, communication, disaster response. We rely on them without thinking, just as we rely on power lines or the internet. Rating: 10/10
Then there’s WALL·E. A lonely robot cleaning up a trashed Earth, eventually punching through a thick layer of space junk orbiting the planet. It’s a whimsical movie, but there’s real gravity beneath the whimsy. The cluttered space WALL·E travels through isn’t fiction, it’s an eerily accurate prediction.
Since Sputnik, we’ve launched over 11,700 satellites. Thousands remain in orbit, and many are no longer functional. Add in the bits of debris, bolts, paint flecks and defunct rockets and you get a dangerous cloud of junk circling the planet at 17,000 miles per hour. One collision can trigger a chain reaction, creating more fragments and danger. It’s called the Kessler Syndrome, and it’s not science fiction.
There’s irony in this. The same dream that launched Homer Hickam’s rockets and the dream of reaching beyond Earth is also the cause of a modern crisis in space. Satellites gave us a new perspective and new capabilities. Now, they threaten to trap us in a prison of our own making.
But maybe there’s another chapter to write. As I sit with my beloved movie-loving dogs, half-lost in the glow of a film and the memory of last night’s skywatching, I wonder: could the next great industry be in cleaning up the satellites we’ve already left behind, rather than launching new ones? Could we build orbital garbage trucks, space sweepers and autonomous collectors? Could we become custodians of our local space neighbourhood? Will we need to?
At Perth Observatory, we’re already assisting with the first steps by hosting COMSPOC. Using advanced tracking technology, COMSPOC monitors the growing cloud of orbital debris as it watches, catalogues and anticipates any collisions. If we don’t act now, there may come a time when we can no longer launch rockets safely. No more October Sky moments. No more international space stations. Just a shimmering belt of debris, circling the Earth like a warning blockade.
For now, though, we still have access to space. We still have dreams. We still have people like Homer Hickam. All while I sit here, movie playing, dogs asleep, telescope waiting by the door for clear skies.
The space age began with wonder. Let’s not let it end with waste.
By Roger Groom
Photography Australia
I facilitated a workshop at the WA Museum as part of their To The Moon special exhibition. This night was a fantastic opportunity to introduce the public to what they could do with their mobile phone to photograph the moon and how this is a great steppingstone in to other types of astrophotography.
It’s easy to know you can point your phone up at the Moon, zoom in as much as you can on your phone’s camera and snap some pics of the Moon. But what other kinds of photographs are you aiming for to make the most or your phone?
Let’s consider some perspectives that will help you make more of your photograph. A recently frequent spectacle has been Moon Halo’s. These 22-degree wide (large) halos appear around the Moon when there is a thin high cloud. That thin high cloud has ice crystals that refract the light coming at us from the Moon, creating a subtle rainbow halo around the Moon.
When you cannot zoom in enough to make out good surface detail on the Moon, consider the Halo, or as illustrated in the photograph here, surrounding landscape such as trees, to make more of your photograph. Continuing on the theme of clouds, let’s not let them get in the way of a beautiful lunar photograph. Here we have lower altitude clouds passing quickly in front of the Moon creating more ‘chunky’ distinct cloud patches around the Moon as opportunities to see the Moon through the gaps present.
And finally, let’s consider the phase of the moon. Full Moon is often not the best time to photograph the Moon, so consider different phases of the Moon to make more of your lunar photography. Using the Terminator (the line between illuminated and dark phases of the Moon) to add more contrast on the lunar elements.
We cover these examples and more in the Perth Observatory’s Lunar Photography workshops, held a few times a year. In fact, the last example was taken during one of these workshops on a small telescope at the Perth Observatory.
When it comes to the technicality of what app to use for photographing the Moon you can try with anything and the default camera apps in phones are often quite capable.
If you want a little more control over your camera and hence photograph, you will want to look for a 3rd party camera app that provides such control.
On the iPhone I prefer to use the app ‘ProCam’. That is not to say it is the only option, but it is a capable one.
The importance of this and other camera apps for lunar photography is:
Being able to control the exposure details and have them ‘stick’ to not change at a whim. You want to be able to specify ISO, Shutter speed and Aperture. You will likely also be able to specify the white balance and while useful is least important typically for the Moon.
Having complete control over the focus. Particularly if you are photographing through the eyepiece of a telescope, you’ll find focus will hunt and randomly change at the least convenient time if you cannot control it specifically.
Saving as high-quality images or RAW so that you have the best you can get from the image from your phone camera.
It’s easy enough to repeatedly tap the shutter button and snap a thousand shots of the Moon, but here are some tips to try and improve your accuracy and results:
Use a phone mount/holder. Whether your phone is being handheld pointing up at the sky, and so a tripod will enable stability if your phone is handheld and pointed at the sky. If you are looking through a telescope, a mobile phone holder will enable precision. Each of these will allow repeatability in pointing your phone, ensuring clean, crisp and vivid images.
Position the phone. If you are using a telescope zoom in on the phone then leave that zoom alone. If you change zoom, you’ll change lenses. In the scenario, you are holding your camera at an eyepiece, this starts to get confusing and difficult with the phone camera software switching between lenses and so switching where you need to position the phone.
Focus and Expose, then hold those exposures. If you are using a default camera app that doesn’t let you manually controls these, tap on the subject, the Moon, and tell the camera to focus and expose correctly for that part of the image.
Manually adjust the brightness to achieve a satisfactory result. Be it shutter speed and ISO, or tap and slide or pinch, the apps will let you adjust the brightness. You might not be seeing lunar detail simply because the moon is overexposed.
As with other types of astrophotography, such as Solar and Planetary, video is often a preferred acquisition method for Lunar Photography.
Recording video has some distinct advantages:
You record continuously, capturing the good and bad moments, you can select the good from the bad later.
You record thousands of individual images, as frames in the video, and, using astrophotography stacking software, you can have a computer process this video and choose the good from the bad. Use all those good frames, and come out with a higher quality “average” of the good frames than you would have had from anyone single image.
The easiest way to take advantage of video is by the first advantage, simply being able to choose a good frame from a video. Consider that if you are recording your video at 4k, you have thousands of images there each at 4k, of the Moon. If you are having difficulty holding the phone steady, or with interfering clouds and such, you can come back later to your video, sift through frame by frame and save out/grab the good frames. For posting online and sharing with friends, those 4k individual frames are easily sufficient quality. While not as high quality as an individual photo, at least you got it!
So, there you go, a bunch of ideas on how you can photograph the Moon. It can be fun and a great way to get young kids, or old kids alike, enjoying time outside under the night sky or using your backyard telescope.
If you want to learn more, the Perth Observatory operates Lunar Photography workshops where we put your DSLR or Mirrorless camera and mobile phones too on our telescopes and telescopes of Perth Observatory volunteer and astrophotographer Roger Groom of Astro Photography Australia. These are light-hearted evenings with a intro indoor session then a bunch of fun at the telescopes.
Discover the secrets of the universe and the rich history of Perth Observatory on our Sunday guided day tours!
Nestled in the stunning bush settings of Bickley, our Observatory is the perfect place to explore the wonders of the cosmos.
Our knowledgeable guides will take you on a journey through time, from the Observatory’s humble beginnings in 1896 to its move to Bickley in 1966 and beyond. You’ll get to tour the Meridian, Astrograph & Calver Telescopes, learn about timekeeping and explore the museum to discover fascinating stories about the Observatory’s past and present.
If the weather permits, you’ll have the opportunity to safely observe the Sun and its sunspots. It’s an experience you won’t want to miss!
There is no need to book, simply come up between 1 and 4 pm and pay in our shop. Our Sunday day tours are the perfect way to spend a relaxing afternoon with family and friends, surrounded by the beauty of nature and the mysteries of the universe.
By Louise Kaestner
The Astrograph is my kind of scope. It brought with it a whole lot of hope.
When you stand beneath the ancient dome, you’ll feel like you have found your home.
Long and thin, elegant of build, within its presence, you’ll feel so thrilled.
It hit WA more than a century past. This telescope was built to last.
It’s the last one standing and it’s fully restored, of all that were made across the board.
Not just for ‘stronomers, but gazers too. It’s a scope that looks into the deep sky blue.
Howard Grubb designed this marvellous tool. Perth grabbed one cuz the scope looked cool.
Made to take pictures of our huge, wide sky, It picks up stuff we can’t see with our eye.
Around 23000 pictures taken by it. This scope’s crew didn’t ever quit.
Special women did the calculations. Every 1 of the 11 were faithful to their stations.
These women made progress and were erudite, working in the background, out of the limelight.
They used old fashion logarithmic scales, regardless of weather: sun, rain, or hail.
Photos of Tarantula and Halley hang on the dome’s wall in view of the gang.
The scope got old and went into disuse. Not once did Perth Obs dish abuse.
But our beautiful girl, our magnificent gal needed some care from an expert pal.
COVID came and it was super strange. It was time for the Astrograph to undergo change.
Lloyd did fix it and made it pure. We use it now on the Full Moon tour.
When the lights go off and the hush settles down, on the big, white moon we see each dip and crown.
The moon looks bright with its awesome craters. This huge telescope could never have haters.
The view you get is one of a kind. It is so incredible it will blow your mind.
People gasp in awe, and go ‘ooh’ and ‘wow’. The view packs a punch and a ‘stronomy pow.
To really get what I’m trying to say, you’ll have to come up on a full moon day.
Image Credit: Matt Woods
by hannah archer
New research from the International Centre for Radio Astronomy Research (ICRAR), in Perth, has used the James Webb Space Telescope (JWST) to study ‘the coevolution of star formation and supermassive black hole growth’ in distant galaxies. Jordan D’Silva, PhD candidate at ICRAR and a lead researcher on the project, explains how a new approach to studying some of the oldest galaxies in the universe has advanced current understandings of our cosmos.
The study was a collaborative effort led by ICRAR, with support from national and international research partners throughout Australia, USA, UK and Italy. It used both proprietary and publicly available data from the Hubble Space Telescope and JWST.
Since its launch by NASA in 2021, the JWST has collected a wealth of astronomical infrared data, building on the contributions of its optical predecessor, the Hubble Space Telescope. Working with raw data from the JWST ‘is no trivial task’, says Jordan:
‘A large part of my PhD was dedicated to data processing, to implementing a novel processingpipelinethatmyself,mysupervisor and other collaborators were involved in… We have this $10 billion telescope. We want to extract its maximum scientific potential. And that involves doing all this kind of grunt work, this quite significant effort, to make sure that [we] can understand the quirks of the data.’
The researchers examined photometric data from 3,751 galaxies, detected by the JWST over a redshift range of 5.5 to 13.5.
This range was selected because it fills a gap in astronomical knowledge known as the Cosmic Dark Ages, parts of space not previously observed by either ground telescopes, which were limited to low redshift windows, or early space telescopes which detected cosmic microwave background radiation at very high redshifts.
The galaxies found in this gap are some of the oldest in the universe, formed only a couple hundred million years after the Big Bang in a cosmological period known as the Epoch of Reionisation. By choosing to focus on them, Jordan and his colleagues could integrate their findings with their earlier galaxy studies, which used ground telescopes and spanned redshifts 5 to 0. The result was a comprehensive overview of the 13-billionyear history of galaxy formation, from the Epoch of Reionisation in the early universe all the way to our local galactic neighbourhood.
In particular, the researchers wanted to examine the relationship between two specific physical processes that occur in galaxies. This is star formation and supermassive black hole growth.
Supermassive black holes are only made visible to astronomers through their activity, such as the outputting of radiation and the accumulation of matter into an observable accretion disk. Together, a supermassive black hole and its visible region of activity are called Active Galactic Nuclei, as they are always found at the center of galaxies.
Astronomers have speculated that stars and Active Galactic Nuclei, being co-evolving, may have an influence on each other’s formation. They share a fuel supply, both feeding on the same gases within a galaxy. It’s also thought that the matter and energy emitted by Active Galactic Nuclei could inhibit star formation, by heating and churning up the gases that would otherwise cool and condense into new stars.
However, usual light-based methods of observation have made it difficult to investigate this formative overlap. Jordan explains, ‘Often the strategy to look at star formation and black hole growth was to look at these processes independently. The reason for that is because it’s very difficult to disentangle those astrophysical processes just from the light that you see. So, you could really only say, oh, this galaxy is dominated by a black hole. This galaxy is dominated by a star. And all the stuff that’s in between [is] a bit confusing and messy, so you kind of just ignore it and look at only these extreme populations.’
To overcome this, Jordan and his research team developed a novel research strategy ‘to disentangle the processes from the light, which previously was very difficult to do. We tried to be a bit more sophisticated in our approach and used more physically motivated models to investigate how stars and black holes formed, to better understand the union of these two processes.’
Their analysis found that, in the distant galaxies of the early universe, rates of star formation were outpaced by the rate of growth of supermassive black holes. This result was confirming of previous experiments, adding weight to the inferences that inform current understandings of the physics and chronology of galaxy formation. Jordan summarises:
‘We’re finding that, tentatively, the black holes are outgrowing the assembly of the stellar mass. So that probably tells us that the gas in those galaxies can somehow fuel the black holes, but it’s a lot harder for that gas to continue to cool, fragment and form stars. Now if you go to, say, a couple billion years after that, star formation and black hole growth seem to co-evolve—they’re not really outpacing each other. So that means at some point you had this kind of turnover, where the conversion of the gas supply to starsandblackholesisequivalent.Afterthat, both black hole growth and star formation tend to decline. That’s basically telling you thatthegasreservoirisdepleting.’
Other than analysing star and black hole formation simultaneously, where in previous studies they had mostly been treated independently, another important aspect of this work was its self-consistency. The researchers applied models developed for the study of galaxy formation in the local universe to their survey of galaxies in the distant, early universe. By using the same light measurements, inference tools and methods of data analysis, they were able to reduce statistical uncertainties and random error. This made it easier to isolate systemic uncertainties, which are produced by consistent factors such as potential anomalies in the physics of the distant versus local universe. Such a robust and consistent analysis provides future researchers with a strong baseline of comparison from which to test alternative models and hypotheses.
This will be important going forward, as many open questions remain. One raised by the study was how the black holes were able to consume more gas than stars. ‘One idea might be that the black holes are ionising the gas, heating it up, but as of yet that question is unsolved,’ says Jordan.
‘There is still much work to be done.’
Looking for an unforgettable night under the stars? Look no further than Perth Observatory’s offsite astronomy nights! As Western Australia’s leading Observatory, our experienced volunteers are dedicated to sharing the beauty and wonder of the night sky with people across the state.
Our team will bring their top-of-the-line telescopes and expertise to your town, suburb or school, providing you with a unique and immersive journey through the Southern Hemisphere’s celestial wonders. We will also guide you through the night sky with the help of our green lasers, teaching you about the stars, planets, nebulas, dying stars and enormous star clusters that populate our universe.
Whether you are an astronomy enthusiast or simply looking for a fun and educational experience, our offsite astronomy nights are the perfect way to explore the beauty and complexity of our universe. Request your night under the stars below and discover the magic of Perth Observatory!
Julia has a smile as big as the sun she’s fascinated with. She brightens up everyone’s day when she’s on a School Day Tour, skilfully explaining complex issues in a fun and simple way. Julia is a popular SDT Host, Presenter, Tour Guide, Solar Telescope Operator and sometimes Fairy.
How long have you been volunteering with POVG and was there something specific that made you want to get involved?
I joined in October 2018. I was doing a week-on/ week-off roster at the time and found I had plenty of spare time off while everyone else was working. I searched Volunteering WA for volunteering opportunities. I have always loved space and science and thought working with the Observatory would be really cool. I initially thought I would be involved in night sky tours but then I realised that the school day tours involved primary school-aged kids coming for excursions, I realised that that would suit me perfectly. Growing up, I initially wanted to be a teacher and I love working with the kids.
Can you tell me a bit about the different roles and responsibilities you’ve taken on as a volunteer here?
I mostly work with the School Day Tours team running activities, hosting the tours and creating the timetables. I also work on any events that involve kids activities, the solar telescope or just generally don’t require too much in-depth space knowledge.
When you’re not at the Observatory, what do you do with your time? Do you have a career that keeps you busy?
I am a senior mining engineer with BHP. I work with other mining engineers and mine schedulers/planners to schedule all the mining activities on-site for plans for the next two years. I like to think of it as one big puzzle making sure everything happens in order to get the right grade and the right number of tonnes on the trains/ships as efficiently as possible. For a long time, I did full-time FIFO on many different rosters but these days I do partial FIFO where I go to site for only two days a fortnight and spend my time at different sites, coaching and mentoring the other engineers. I now work ‘normal’ Monday-Friday work weeks, but I manage my time at the Observatory by working flexibly. I take time off from work and replace those hours when it suits me so I can be at the Observatory during the school day for the School Day Tours.
Q & A with
POVG Volunteer Julia Serjeantson with Julie Matthews
Outside of volunteering, do you have any hobbies or activities that you enjoy? What sorts of things do you like to do for fun?
My main hobbies are playing boardgames with friends and travelling. Sunday afternoon is often boardgame time for me and my friends where we play anything from Bananagrams and Love Letter to Dominion and Gloomhaven. I have a fairly extensive boardgame collection but am always keen to learn and play new games. I always like to have my next big travel destination on the cards that I can look forward to and plan, as well as going over East to visit family a few times a year.
What would you say is the most rewarding or enjoyable part of being a volunteer at POVG for you?
My favourite part about being a volunteer is that I get to give back to the community in some way while having fun with the visitors and the other vollies. I remember going to Green Point Observatory in NSW as a kid on their open nights learning all about the stars from their staff and I love that I get to be that for the kiddos that come to Perth Observatory. I love that I get to have my little foray into teaching and get to play a part in shaping the little minds that come through our doors. I really enjoy that you can have fun with the kiddos while teaching some really cool things about space.
I love teaching the kids something new and seeing the moment when they fully grasp the concept. This happened the other week while teaching seasons and solstices. It also happens a lot with teaching the order of the planets and how we only ever see one side of the moon even though it does actually rotate. These things can stick with the kids into adulthood and maybe one of them will remember learning the order of the planets at the Perth Observatory. As a kid and I love being involved in that.
Over the past six years, you must have had some memorable moments at POVG. Is there a particular memory that stands out for you?
Wow, there’s so many memories it’s hard to choose. I really enjoy working with the new solar telescopes because I think it’s so incredible that we can look at the sun directly and safely with a telescope and see all the sunspots and solar activity. I do remember a few months ago setting it up and there being so many sunspots, set up as the corners of a square with one corner having a huge array of sunspots. More than I had ever seen before, I got very excited and told everyone in the office to go have a look through the telescope at some point and then showed the students and accompanying adults throughout the day.
I also loved the Fairy Afternoon Tea Day, where the parents/adults would tell their kiddos to go talk to the ‘monarch butterfly’ to learn all about the sun. Then chatting to the little fairies and elves about the sun, showing them pictures and using the telescope and sun spotters when the clouds allowed.
For someone just starting out as a new volunteer, what tips or advice would you give to help them settle in and make the most of the experience?
It’s similar advice that I would give to new starters at any new workplace, say yes to opportunities and ask lots of questions. It’s ok to not know the answers to everything (or even anything!). We all started somewhere and everyone has different strengths. So come along to different events when you can, learn what you can from the different resources on offer and enjoy it!
Are you into science fiction or fantasy? If so, do you have a favourite movie or book in that genre?
At the risk of being ousted from the Observatory, sci-fi isn’t really my genre. My favourite sci/fi board game is Terraforming Mars. Though if that counts.along to different events when you can, learn what you can from the different resources on offer and enjoy it!
Looking ahead, do you have any future goals or plans, whether related to your volunteering or other areas of your life?
My main plans at the moment involve my next holiday. I plan to go to Europe for 10 weeks. I’m going to visit friends, explore the Christmas Markets and hopefully catch the Aurora Borealis. Hopefully, the sun is nice and active, and the clouds part and I can live my dream of the aurora dancing above me, if not I will enjoy playing in the snow and making friends with the huskies and reindeer.
Thank you Julia for inspiring so many children (and adults) to learn more about our universe. Fingers crossed that you get to see the aurora! We look forward to checking out sunspots with you at the Observatory.
Looking for a unique gift to recognise a special family member or friend? Look no further than our star adoption program! Our program allows you to adopt a star between magnitudes -1 and 7.9 in the Southern Hemisphere, visible to the naked eye or in binoculars.
Each star adoption package includes a certificate with the star’s name and coordinates, as well as the duration and purpose of the adoption. Plus, you and up to three guests can enjoy a private star viewing night within 12 months of the adoption, where you’ll get to see your chosen star and other seasonal objects. We’ll also provide you with a planisphere and star charts, so you can continue to enjoy your star long after your viewing night.
Please note that while we don’t offer international naming rights for stars, the income from our program goes towards supporting the Perth Observatory’s not-for-profit public outreach program. Adopt a star today and give the gift of wonder and discovery!
Anthology of astronomy articles appearing in several magazines and newsletters over the past six years. Amateur astronomers of every level and any (or no) equipment will find fresh takes on our hobby, including ideas to expand your observing and get more from the night sky.
Cooper Weckert. Why? Because he brings Uno, Monopoly Deal or another card game to while away the time during the quiet periods on a Sunday afternoon.
El Mauger. Why? For the brilliant job done with editing the tourism awards.
Nadia Maslen. Why? Because she does an incredible job above and beyond her paid position to bring forward new recruits.
Paul Fischer. Why? For being as regular as a sunset on Friday and Sunday nights at Perth Observatory. send submissions for inclusion in the Perth Observatory Newsletter Shout Outs:
Steve Webb. Why? For being a telescope Jedi and a regular go-to for his Padawans.
Looking to volunteer and make a difference in the lives of primary school children? If you have free time during the day and a passion for learning about space and our solar system, we invite you to join our School Day Tours Team as a volunteer!
As a member of our team, you will have the opportunity to share your knowledge and enthusiasm with young students while learning from experienced educators. No prior experience is necessary, as we provide all the training you need.
If you enjoy working with children, this could be the perfect opportunity for you! All you need to bring is your enthusiasm, a friendly demeanour, and the ability to communicate with children.
To learn more about how you can get involved, click below and let’s start making a difference in the lives of young students today.
Last year, on the 11th of May, I saw the Aroura Australis. It was colourful, bright, and cheerful! Its light lit up the sky. To see the aurora, I went with my parents to Lake Leschenaultia, where there were lots and lots of other people there to see the aurora. It was a big surprise to see so many people at the lake.
We could see the Aurora because the Sun blasts energy off towards Earth, and that energy interacts with the atmosphere of Earth and that makes the colours in the sky. You could ask your parents about the aurora to learn more.
It was visible from sunset all the way into the night. It is very rare to see the aurora at sunset in your cameras!
My camera didn’t really work for the Aurora, so I borrowed one of my dad’s cameras. Some cameras work and others don’t work so well for the Aurora, but it was fun to photograph anyway! The contrast of the bush and the lake was perfect for photos. Here are some of my photos.
When I look at the night sky and I see a nebula or a star, it brightens up my day.
by Paul fiSher meng, mSc
Look south on a clear night, and the unmistakable sight of the Southern Cross is readily visible. Just to make things easier, the two bright ‘pointer’ stars show the way to the cross. The brighter of the two pointers is Alpha Centauri (α Cen), apparently the third brightest star in the night sky after Sirius and Canopus.
Look at α Cen through a small telescope, and you’ll see two stars, side by side. Yes, α Cen is a double star, the first one that any neophyte astronomer learns about. But a much larger telescope or astrophotograph reveals a tiny red dot near the bright pair, this is Proxima Centauri, a tiny red dwarf all but lost in the background of stars. If you carefully measure the position of Proxima over a long time period, you will see that it is in orbit about the bright pair. So α Cen is not in fact a double star, but a triple star system.
The α Cen system is the closest to our Solar System, at only 4.3 light years away. At its current point in its orbit Proxima is the closest individual star to us, hence its name.
Alpha Centauri A and B form a close binary pair, in an elliptical orbit that ranges from about 11 astronomical units (AU) to about 36 AU. In Solar System terms, the distance between the stars varies from roughly the Sun-to-Saturn distance at closest encounter (periastron) to the Sun-Pluto distance at apastron. The next periastron (closest encounter) will occur in 2035.
α Cen A - also called Rigil Kentaurus - is the largest star in the system and is a G-class star like our Sun. It’s about 10% more massive than the Sun with a diameter 22% larger. α Cen B - aka Toliman - is a K-class star, having a more orange colour. It weighs about 90% of the Sun’s mass and has a diameter 14% smaller.
α Cen C (Proxima) is by far the smallest of the trio, a red M-class star, only 0.12 solar masses. Its orbit about the AB pair is elliptical, varying between 4,100 AU at periastron out to 12,300 AU. Proxima takes over half a million years to complete one orbit.
With α Cen being so (relatively) close to Earth, our thoughts naturally turn to the questions of whether there are planets, maybe even lifebearing planets, in the system. The stars are close enough that direct imaging of planets should be possible; however, this is complicated by the presence of the other system members. The glare from Rigil Kent may obscure views of a planet around Toliman (and vice versa).
Additionally, the presence of the other stars may perturb the orbits of any planets around Rigil Kent and Toliman. Any such planets would need to be very close to their primary star to maintain a stable orbit.
α
In 2019, Kevin Wagner and his team used the Very Large Telescope to survey the α Cen system for planets. The techniques used were written up in Nature Communications and demonstrate the complexity of this type of astronomy. After 100 hours of telescope time, a possible exoplanet was seen within the habitable zone of α Centauri A. Of the 100 hours of data, about 20% had to be discarded due to sky conditions, instrument misalignment and other reasons. Accordingly, the object could not, with certainty, be classified as a newly discovered planet.
The arrival of the James Webb Space Telescope (JWST) provided a new tool of exquisite sensitivity, ideal for planetary surveys. Charles Beichman and team used the JWST to search for planets in the α Cen system. In August 2024, the team discovered a point source corresponding to a planet the size of Jupiter. Follow-up observations in February and April 2025 failed to recapture the object. However, the authors point out that the system’s orbital mechanics may have shielded the planet candidate from view during these later observations. Taking an optimistic view, Biechman asserts that combining the 2019 and 2024 observations could reveal a planet with an orbital period of 2-3 years, a mass of 90-150 M Earth and a radius of 1.0-1.1 R Jupiter. Further work is obviously required to firmly establish whether the object is, in fact, an exoplanet.
α Cen B
In 2012, an Earth-sized planet was reported orbiting α Cen B. The team led by Xavier Dumusque used the radial velocity method— taking ultra-precise measurements of wobbles in the star’s orbit caused by the gravitational attraction of a possible planet. This is accomplished by measuring tiny red and blue shifts in the star’s spectrum. The analysis was complicated by weakness of the observed effect and potential interference by α Cen A.
Debate about the alleged finding raged for several years, until a team from Oxford University proved that the signal was an artefact of the mathematics used for the initial analysis. Following the release of the Oxford paper, Dumusque conceded that the planet likely did not exist.
α Cen C (Proxima Centauri) is remote from the α Cen AB pair and has a much lower mass. These factors mean that detection of planets about this star should be relatively easier.
Indeed, in 2016 an Earth-sized planet was detected by analysis of the star’s spectrum. This planet, known as Proxima Centauri b, orbits very close to Proxima at only 0.048 AU and orbits the star in only 11.2 days. This puts it near the inner edge of Proxima’s habitable zone, where the temperature is potentially suitable for the presence of liquid water. Could this be a life-bearing planet?
The second planetary candidate Proxima Centauri c was reported by Mario Damasso in 2019. Proxima c would have been a super-Earth/sub-Neptune planet, possibly with a ring system, orbiting at 1.5 AU from the star. Subsequent studies have cast doubt on this candidate, though with the possibility of a much smaller planet in the same orbit ascribed to Proxima c. At this time, Proxima c remains an unproven candidate.
Proxima d is the second confirmed planet orbiting α Cen C. It is much smaller than Earth, and orbits close to the star at 0.03 AU, and with a “year” of only five days. Proxima d was first detected in data from the Very Large Telescope in 2020 and confirmed by a number of follow up studies. It is likely tidally locked to Proxima, and too hot to support life as we know it.
In recent years the criteria for potential life-bearing planets have broadened to include moons such as Europa and Enceladus. Planets outside a star’s habitable zone may have conditions similar to those found on those two moons.
Having said that, only one of the planets and candidates described above is considered habitable – Proxima b. The others are either too close to their star (e.g. Proxima d) or else gas giants (Proxima c, α Cen Ab).
Proxima b is only 0.048 AU from the star and is almost certainly tidally locked, with one side always facing the star. This in turn means that the planet likely has a very weak (if any) magnetic field. In the absence of a strong magnetic field, the planet’s surface would be vulnerable to atmospheric stripping by the stellar wind and coronal mass ejections (CME).
And here lies the problem – Proxima is a flare star, subject to frequent and violent eruptions and CMEs. In fact, it is one of the most violent red dwarfs. Notwithstanding this, some authors believe that the magnetic field of a tidally locked planet may still be sufficient to provide adequate protection.
My personal view is that the odds of life (as we know it) developing on any of the α Cen system planets is a long shot. While we have discovered several planets in our neighbouring system, conditions generally are not conducive to life...
A pity!
BY JULIE MATTHEWS
I picked this book up thinking I’d be diving into a sci-fi time travel adventure, hello, Doctor Who, but instead found a lively mix of thrills, an immigrant story, conspiracy and a dash of light-hearted romance. For a relatively slim book, it sure packs a lot in!
The Ministry of Time is set in a not-so-distant future where time travel has been discovered and kept strictly under wraps. The shadowy ‘Ministry’ secretly plucks historical figures right before their deaths and whisks them into the present for study. These bewildered refugees are then paired with a ‘bridge’, a civil servant who must share their home with one of the expats, help them adjust to modern life and file detailed reports back to HQ.
Our narrator is a second-generation Cambodian immigrant tasked with helping Commander Graham Gore, an expedition leader from Sir John Franklin’s doomed 1840s Arctic mission. The poor man is horrified to find himself living under the same roof as an unmarried woman, much to her amusement and frustration.
The book sparkles with memorable characters, including two delightfully gay expats who revel in the freedoms of modern life. It’s fascinating to watch figures from the past wrestle with everyday things we take for granted, phones, electricity, takeaway food and television.
The prose is sharp and witty (I wish I could speak as cleverly as these characters do!). The Ministry of Time is beautifully written and slyly funny. The ending ties everything together with satisfying twists while revealing the true identity of our narrator.
The Ministry of Time is a smart, engaging and enjoyable read.
JULIE ’ S RATING
Millions of stars in the night sky produce the magical moments for those who admire them. Most importantly, the Sun, a star among billions of stars in the Milky Way Galaxy, is central to our life on Earth. Most cultures have recognised the significance of the Sun as the prime controller of all life on Earth since prehistory.
By Harry Murari
Let us briefly look at astronomers’ viewpoints in history. Claudius Ptolemy (100-170) set up a model of the solar system in which the sun, stars and other planets revolved around Earth. Nicolaus Copernicus (1473 -1543) challenged the long-held notion that the Earth was the centre of the solar system and proposed a sun-centred model.
In 1609, Johannes Kepler’s model, each planet moves around the Sun in an orbit that is an ellipse, with the Sun at one of its focal points. He is the first to suggest that the Sun rotates on its axis. Galileo Galilei (1564–1642) was known for defending sun centred model and because of this, Galileo was put under house arrest until his death in 1642.
There is consensus that our Sun formed about 4.6 billion years ago from a molecular cloud of gas and dust. It is estimated that Sun-like stars form in approximately 10 million years. The Sun is a G-type main-sequence star (G2V), with G2 standing for the second hottest stars of the yellow G class and the V representing a main sequence on the Hertzsprung-Russell diagram. It is perceived as a yellow star, but its light is white. Every second, the Sun’s core fuses approximately 600 million tonnes of hydrogen into helium, converting 4 million tonnes of mass into energy in the process.
The Sun orbits the Galactic Centre at about 28,000 light-years. Its distance from Earth defines the astronomical unit, which is about 150 million kilometres or about 8 light-minutes and 20 seconds. The Sun does not have a definite boundary; its density decreases exponentially with increasing altitude above the photosphere.
For measurement, the Sun’s radius is the distance from its centre to the edge of the photosphere, the apparent visible surface of the Sun. Its diameter is about 1,391,400 km, 109 times that of Earth. The Sun’s mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. The various planets were formed from the solar nebula, the disc-shaped cloud of gas and dust, left over from the Sun’s formation. The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma.
Sun’s workings continue through its layers:
Core – The heart of nuclear fusion of hydrogen into helium at 15 million degrees Celsius, four hydrogen atoms merge to form one helium atom, liberating vast amounts of energy in the process. Almost half the Sun’s mass resides here.
Radiative Zone – A layer where radiation is the primary means of energy transfer.
Convective Zone – Energy is transported through gas currents, similar to boiling water in a pot.
Photosphere – The visible ‘surface’ of the Sun, from which light and heat escapes. Surface temperature is about 5,500 degrees C.
Chromosphere – The red-coloured layer just above the photosphere.
Corona – The Sun’s outermost layer, visible only during a solar eclipse. The corona’s temperature is about 1 million degrees C or more.
Energy generated in the core travels outward through these layers, emerging as sunlight and heat that sustains life on Earth. It takes around 100,000 years for light and heat generated in the Sun’s core to reach its surface. Energy from the Sun drives Earth’s weather and climate. It heats the planet, stimulating wind currents and the water cycle. The Sun’s energy also enables photosynthesis, supporting life to flourish on Earth.
Plasma in motion drives a dynamo that generates a global magnetic field as well as smaller-scale local fields. The Sun’s magnetic fields store enormous amounts of energy, which can be released gradually or explosively. The solar magnetic system is known to drive the approximately 11 year activity cycle on the sun, a solar minimum when solar explosions are least frequent. From that point, the sun’s magnetic field grows more complicated over time until it peaks at solar maximum.
The sunspots are the cooler regions on the Sun caused by a concentration of magnetic field lines. Sunspots are the visible component of active regions, areas of intense and complex magnetic fields on the Sun that are usually the source of solar eruptions. Sunspots can be seen on the Sun’s photosphere, or visible surface of the Sun.
A solar storm is a sudden disturbance on the Sun that releases energy in the form of solar flares and coronal mass ejections (CMEs). When directed toward Earth, a solar storm can create a major disturbance in Earth’s magnetic field, called a geomagnetic storm that can produce effects such as radio blackouts, power outages and beautiful auroras. Solar flares take about 8 minutes to reach Earth, and CMEs take about 1 to 3 days.
In 1859, astronomer Richard Carrington saw a blast of white light on the surface of the Sun. This was named the Carrington Event. It is the largest solar storm ever recorded, and in terms of rating, it is around X-45. It was linked with extraordinary auroras, the Northern and Southern Lights, a magic dance in the night sky.
The solar wind is matter that is blown from the sun, out into the whole solar system. This stream of material is coming out of the sun all the time at a speed of 300 to 800 kilometres per second. It travels through the solar system, interacting with anything that gets in its way, like the Earth or other planets. Solar wind is a combination of protons, electrons, alpha particles and magnetic fields.
The solar wind, which ultimately travels past all the planets to some three times the distance to Pluto before being impeded by the interstellar medium. This forms a giant bubble around the Sun and its planets, known as the heliosphere, and it is understood to play a crucial role in protecting the solar system from many of the harmful particles and radiation from the interstellar space.
Activity on the Sun’s surface creates a type of weather called space weather. Space weather can affect Earth and the rest of the solar system. It can even damage satellites and cause electrical blackouts on Earth. Scientists do make predictions about when solar storms are likely to occur and how strong they will be.
Spacecraft monitoring the Sun include WIND, SOHO, ACE, Hinode, STEREO, Solar Dynamics Observatory, IRIS, Parker Solar Probe, and Solar Orbiter.
The WIND spacecraft launched in 1994. Involved in studies of statistical solar wind trends, magnetic reconnection, large-scale solar wind structures, electromagnetic turbulence, coronal mass ejection topology, interplanetary and interstellar dust, solar radio bursts, solar energetic particles and so on.
SOHO, Solar and Heliospheric Observatory mission was launched in 1995. It’s become the longest-lived satellite watching our star, but it has also become a comet hunter. It has discovered over 5,000 comets.
ACE, Advanced Composition Explorer was launched in 1997. Its first job was to observe what kinds of matter and energy arrive at Earth from the Sun and from across the galaxy. ACE has studied the full range of emissions from the Sun, such as CMEs, as well as the constant outward flow of solar material called the solar wind.
Hinode’s Solar Optical Telescope, launched in 2006, is the first space-borne instrument to measure the strength and direction of the Sun’s magnetic field on the Sun’s surface, the photosphere.
STEREO (Solar TErrestrial RElations Observatory) is a solar observation mission, launched in 2006. The STEREO satellites principally monitor the far side for coronal mass ejections, massive bursts of solar wind, solar plasma
The Solar Dynamics Observatory (SDO) which has been observing the Sun since 2010. It is used in providing early warnings to satellite operators. SDO carries three instruments: the Helioseismic and Magnetic Imager (HMI), the Atmospheric Imaging Assembly (AIA) and the Extreme Ultraviolet Variability Experiment (EVE). HMI studies changes in the Sun’s magnetic field by capturing images of the Sun in polarised light every 50 seconds. AIA observes the solar corona in eight wavelengths of ultraviolet light every 10 seconds. EVE determines every 10 seconds how much energy the Sun emits at extreme ultraviolet wavelengths.
IRIS, Interface Region Imaging Spectrograph, was launched in 2013. It is there to observe how solar material moves, gathers energy and heats up as it travels through a little-understood region in the sun’s lower atmosphere.
Parker Solar Probe (PSP) launched in 2018 to make observations of the Sun’s corona. Parker Solar Probe makes history with closest pass to the Sun. It captured unprecedented insights into solar winds. The Probe observed its magnetic field switchbacks – sudden reversals in the direction of the magnetic field carried by the solar wind. PSP discovered evidence of a cosmic dust-free zone. The probe observed “rogue” electromagnetic waves in the solar atmosphere that instantly increase solar wind speeds.
The Solar Orbiter was launched in 2020. It is the most complex scientific laboratory ever to have been sent to the Sun. Solar Orbiter takes images of the Sun from closer than any spacecraft before and for the first time look at its uncharted polar regions. Exploring:
Solar wind formation — the stream of charged particles that influences space weather and Earth-based technologies.
Magnetic field reversals — which drive the Sun’s 11-year activity cycle.
Rare phenomena — such as polar vortices, similar to those observed on Venus and Saturn.
Solar Orbiter has revealed that tiny, hair-like jets in the Sun’s coronal holes are responsible for both fast and slow solar wind.
The Southern Lights (Aurora Australis) and the Northern Lights (Aurora Borealis) are caused by charged particles from the Sun interacting with oxygen and nitrogen molecules in the Earth’s atmosphere, causing them to become ionised and emit light. The protective magnetic field around Earth shields us from most of the energy and particles. When a solar storm comes toward us, some of the energy and particles can travel down the magnetic field lines at the north and south poles into Earth’s atmosphere. There, the particles interact with gases in our atmosphere, resulting in beautiful displays of light in the sky. Oxygen gives off green and red light. Nitrogen glows blue and purple.
An equinox is a moment that the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of approximately equal length.
The Earth is slowly drifting away from the Sun, by about 6cm per year, due to the Sun’s gradual loss of mass as it converts hydrogen into helium through nuclear fusion. This applies to other planets and objects in the solar system.
More than half of all stars in the sky have one or more partners. The Sun is a single star in our solar system. A world with two suns would present significant differences compared to our single-sun solar system, primarily impacting climate, prolonged periods of darkness and light and more.
About 7 billion years from now, when hydrogen fusion in the Sun’s core diminishes to the point where the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature, and in that process, its outer layers will expand, eventually transforming the Sun into a red giant. After the red giant phase, models suggest the Sun will shed its outer layers and become a dense type of cooling star (a white dwarf), and no longer produce energy by fusion, but will still glow and give off heat from its previous fusion for perhaps trillions of years. After that, it is theorised to become a super-dense black dwarf, giving off negligible energy.
By Louise Kaestner
We’re sitting in the theatre room. There is a frozen image of our glorious sun at the front. Next to me is Cooper Weckert. The Perth Observatory Volunteer Group shirt covers his tall and lanky frame. His name badge is pinned. It’s his first day wearing it. Cooper’s light brown hair crowns a strong jawline. His brilliant blue eyes twinkle in the bright lights of the theatre, and a grin slips onto his face. When he speaks, his voice is soft but clear. This is our interview on the 31st of August 2025, before the Sunday afternoon rush of eager tourists.
What inspired you to volunteer at Perth Observatory?
Mainly because I’ve liked astronomy for a while. I like space. I like photography. When we first came here to ask about volunteering, we talked to Roger about lunar photography and what he does. We thought maybe volunteering to help him would be a good idea.
What challenges do you face as a volunteer?
I mainly work on the till. The only thing that I think I’m going to have any trouble with is when there’s a massive rush of people. Outside of volunteering, it’s usually meeting new people is a bit difficult for me. I struggle quite a lot to remember people’s names. Usually, I don’t use them. It does take me a little while to feel comfortable in a new setting, so trying to get better at coping with them.
Well, having Jack as my support worker is very helpful. I also have an occupational therapist who’s quite good at helping me work through these things.
is easy about being a volunteer?
I’ll be honest. It’s playing Uno while we wait for customers. I like that, yeah.
What do you enjoy about being a volunteer?
I get to volunteer at a place that has something to my passions. I like the people here, everyone. It’s a place to volunteer. I like it. We like having you here, too.
Do you have any previous volunteer experience?
I did school photography. I helped. I didn’t help take the photos. I helped like assigning the photos to the right name. And I did volunteer at a bookstore in Guildford.
Well, I like tabletop games like Dungeons and Dragons. There are a lot of other ones, but that’s the main one. I like card games, writing, reading, board games, video games and mountain bike riding.
I was doing it for a little while, but then it became hard because my back started getting bad. You’re always leaning over when you’re riding.
Favourite planet, star (or star system), nebula, cluster or galaxy?
Technically, it’s not any of those. It’s TON 618, the largest black hole that they’ve ever found. It’s awe-inspiring but also terrifying, because this thing is so massive you can’t even imagine it.
How massive?
Apparently, it could fit millions of our solar systems in it. And it’s also so big that it’s got another black hole orbiting. It’s forcing another black hole to go around it.
Do you have a favourite telescope to look through or use?
Well, the only telescope I use is my dad’s. He had one at home and it’s broken. I think something’s wrong with it. We haven’t used it.
I’d say volunteering here. It’s allowing me to get more used to being in a workspace. This was the whole goal of me volunteering here.
What is easy about being a volunteer?
I’ll be honest. It’s playing Uno while we wait for customers. I like that, yeah.
And how did you get so good at card games, like Uno?
I started playing them regularly since Jack. We meet every Tuesday. I also have another support worker on Wednesday. So, I usually play board games with them at least once a session.
Unfamiliar voices echo down the hallway. I click off the record button on my phone. The three of us, Cooper, Jack and I, leave the presence of the theatre to spend another day informing the curious public about the historic Perth Observatory site. As we walk down the hallway, I ponder how remarkable this young man is and how badly he will beat me with today’s deck of cards: Uno: No Mercy.
The delightful volunteer Ann Taylor suggested that the readers of the Perth Observatory Newsletter should have a competition to decide on a worthy name for our out-of-this-world publication. She also suggested that the winner receive either a Mars or Milky Way. I agree with her. However, I’ve tossed in the choice of a fridge magnet for people who shouldn’t eat the chocolates. The rules are simple:
No copyright infringement. You have a great idea? Excellent. Google it to make sure someone else doesn’t have it.
Must be original, unique and creative. May absolutely push the boundaries of sanity.
Can be quirky. Please, nothing average.
Must represent astronomy and/or Perth Observatory.
You will need to submit your email address, personal name (for credit), suggestion and choice of prize. In the next issue, we will vote on the names and the prize will be awarded for the name chosen.
By Louise Kaestner
Supernovas, like life, are always evolving and keen to astonish both professionals and amateurs alike. A study published in Nature on August 20 revealed that we are still many light-years away from understanding the process of a star’s death. At 2 billion light-years away, SN2021yfj revealed its oxygen, silicon and sulphur layers to curious Northwestern University astrophysicists before exploding into the delightful event we know as a supernova.
Supernovas occur when stars burn all their fuel and explode. These stars, massive stars, must be above 8-10 solar masses (SM) above our sun, which is worth 1 solar mass. After exploding, the supernova often becomes a black hole. For a star with less than 8 solar masses, like our sun, the star burns all its hydrogen into helium, expands towards our solar system’s asteroid belt and turns into a white dwarf. The core of this will be mostly carbon and oxygen, with a thin layer of helium surrounding it. Once a white dwarf, there is no further nuclear fusion occurring. Therefore, the star cools as there is no energy production.
The supernova SN2021yfj drew global attention over the second half of August because, as it burned its fuel, it became stripped down to what the scientists call ‘bare bones’. This is an unusual event to witness. This supernova challenges previous thoughts on the process of a supernova. The challenge lay in the fact that the star lost its outer layers prior to explosion, rather than during. Another thought that astrophysicists were challenged by was the fact that the elements in this supernova were silicon, sulphur and argon in large amounts rather than being mostly carbon or oxygen.
Stars begin in wombs called molecular clouds. Unlike wombs, molecular clouds are cold. Gases clump, forming high-density pockets. As the clumps collide or collect more matter, they gain mass and their gravitational force grows. When gravity causes these clumps to collapse, friction makes them hot, and they become protostars, or baby stars. Fusion is not yet taking place because though they are hot, they aren’t yet hot enough. When enough of these stars accumulate into a batch, astronomers call these batches clusters. When there are a few star clusters in a molecular cloud, stellar nurseries occur.
The protostar begins to burn energy as disturbances in the molecular cloud, such as nearby supernovae, send it spinning. The star then generates a strong magnetic field. This magnetic field keeps the atoms that collide during fusion within the star’s mass. When the core temperature exceeds 10 million K, the protostar becomes a main-sequence star Smaller stars, with 0.08 times the sun’s mass, become brown dwarfs. These are stars that never ignite because they don’t have enough fuel to begin burning.
There are 7 main types of main-sequence stars. These are O (Blue; 50 SM), B (Blue; 10 SM), A (Blue; 2 SM), F (Blue/White; 1.5 SM), G (White/Yellow; 1 SM), K (Orange/Red; 0.7 SM) and M (Red; 0.2 SM) stars. A common mnemonic for remembering this sequence was: Oh Be A Fine Girl Kiss Me. There are also giant stars, white dwarfs and supergiant stars. Giant stars are low-mass stars nearing the end of their life. White dwarfs are the remnants of a dying star. Supergiant stars are stars of a high mass nearing the end of their life.
Astrophysicists define stars using a spectrograph. Spectrographs split light into its component wavelengths. These wavelengths help scientists learn what kinds of elements a star is burning or emitting. Spectrographs may be handheld, or they may be as large as the WHT Enhanced Area Velocity Explorer (WEAVE). The astrophysicists who saw SN2021yfj, in all its naked glory, used a wide-field ZTF camera attached to a 48-inch Samuel Oschin robotic telescope (P48) at the Palomar Observatory in Southern California, USA. The mosaic science camera operates on multiple levels, including as a spectrograph. The images from this camera revealed what elements the supernova was burning prior to exploding. Isn’t science neat?
James Bradley’s quiet brilliance reshaped our understanding of the cosmos.
By Mary Hughes
James Bradley was educated at Balliol College, Oxford, where he received a B.A. in 1714 and an M.A. in 1717. His uncle, the Rev. James Pound, a clergyman and himself a skilled amateur astronomer, instructed him in observational astronomy at Wanstead, Essex. He also introduced him to the then famous astronomer Edmund Halley.
Maybe it wasn’t surprising that in 1742, James Bradley succeeded Edmund Halley as Astronomer Royal at Greenwich. Fortunately, unlike his 2 predecessors his enhanced reputation enabled him to apply successfully for a set of instruments costing GB£1,000; and with an 8-foot quadrant completed for him in 1750 by John Bird, he accumulated at Greenwich in ten years materials of inestimable value for the reform of astronomy. A crown pension of GB£250 a year was conferred upon him in 1752.
He is best known for two fundamental discoveries in astronomy:
The aberration of light (1725–1728),
The nutation of the Earth’s axis (1728–1748).
It is to these two discoveries by James Bradley that we owe the exactness of modern astronomy. Bradley was elected a fellow of the Royal Society on 6 November 1718. In 1721 Bradley was appointed as Savilian professor of Astronomy at Oxford. Bradley measured the diameter of Venus with a large aerial telescope - objective focal length of 65 m.
As is often the case, his discovery of the aberration of light was made while attempting to detect stellar parallax. Bradley worked with another astronomer Samuel Molyneux setting up a zenith pointing telescope to try to measure the parallax of Gamma Draconis (a star in the northern constellation of Draco).
This stellar parallax ought to have shown up, if it existed at all, as a small annual cyclical motion of the apparent position of the star. However, while Bradley and Molyneux did not find the expected apparent motion due to parallax, they found instead a different and unexplained annual cyclical motion. Bradley later used the same method to discover the aberration of starlight, an apparent slight change in the positions of stars caused by the yearly motion of the Earth. The basis on which Bradley distinguished the annual motion actually observed from the expected motion due to parallax, was that its annual timetable was different. The diagram below demonstrates parallax.
Bradley further calculated that, if there had been any appreciable motion due to parallax, the star should have reached its most southerly apparent position in December, and its most northerly apparent position in June. What Bradley found instead was an apparent motion that reached its most southerly point in March, and its most northerly point in September; and that could not be accounted for by parallax. A story has often been told, that the solution to the problem eventually occurred to Bradley while he was in a sailingboat on the River Thames.
He noticed that when the boat turned about, a little flag at the top of the mast changed its direction, even though the wind had not changed; the only thing that had changed was the direction and speed of the boat. Bradley worked out the consequences of supposing that the direction and speed of the earth in its orbit, combined with a consistent speed of light from the star, might cause the apparent changes of stellar position that he observed.
He found that this fitted the observations well, and also gave an estimate for the speed of light, and showed that the stellar parallax, if any, with extremes in June and December, was far too small to measure at the precision available to Bradley. (The smallness of any parallax, compared with expectations, also showed that the stars must be many times more distant from the Earth than anybody had previously believed.)’
This finding provided the first direct evidence for the revolution of the Earth around the Sun and supported the correctness of Aristarchus’ and Kepler’s theories. The announcement was made to the Royal Society in January 1729.
Having confirmed his theory of the aberration also gave Bradley a means to improve on the accuracy of the previous estimate of the speed of light. After the publication of his work on the aberration, Bradley continued to observe, to develop and check his second major discovery, the nutation of the Earth’s axis, but he did not announce this in print until 14th February 1748, when he had fully tested its reality by minute observations during an entire revolution (18.6 years) of the moon’s nodes.
Bradley retired in broken health, nine years later, to the Cotswold village of Chalford in Gloucestershire, where he died at Skiveralls House on 13 July 1762. The time and effort to record the calculations over such a long period of time must have taken its toll.The publication of his observations was delayed by disputes about their ownership; but they were finally issued by the Clarendon Press, Oxford, in two folio volumes (1798, 1805).
The insight and industry of Friedrich Wilhelm Bessel were, however, needed for the development of their fundamental importance. It wasn’t until 1838 that Bessel announced that 61 Cygni (a binary star system in the constellation Cygnus) had a parallax of 0.314 arc seconds; which, given the diameter of the Earth’s orbit, indicated that the star was 10.3 light years away.
Given the current measurement of 11.4 light years, Bessel’s figure had an error of 9.6%, which was the most accurate proof of parallax and he was credited with the discovery. Unfortunately, this discovery had eluded James Bradley. James Bradley was awarded the Copley Medal in 1748;
“On account of his very curious and wonderful discoveries in the apparent motion of the Fixed Stars, and the causes of such apparent motion”
A fitting tribute I think!
Sometimes I sits and thinks and sometimes I just sits.
Or the musings of a man who should be mowing the lawn.
By John Tuffin
On the few occasions I sits and thinks, I occasionally thinks about ‘time’. First: What is it? We are slaves to it in our daily lives, and we are excellent at measuring it, but what is it and how does it relate to Einstein’s space-time? Is it just a construct of the human imagination? Second, what does it mean to think about “the time before the Big Bang”?
We know that time never stands still, because everything is always changing, and nothing can change without having time to do so. Mountains rise and crumble and take millions of years to do so, while each of our body cells has millions of organelles whizzing around and bumping into each other billions of times per second. Of course, there are an infinite number of other examples,
And the second question relates to the first. According to the Big Bang Theory (and I am not talking sitcoms here), time and space were created in the Big Bang. Try getting your head around that!!! What was before the Big Bang, and if time was created in it, can we even talk about ‘before the Big Bang’? Not according to Stephen Hawking. Hawking says, asking that question is like asking “what is north of the North Pole?” Sometimes it hurts when you “sits and thinks”.
It is often said that the answer probably belongs in a realm beyond the human imagination. However, even though that is likely to be the case, I like to try. It’s easier and more interesting than mowing the lawn, which I should be doing now. My hypothesis is that time must have been created in the Big Bang along with everything else.
It is only from the Big Bang forward that anything existed, and if absolutely nothing exists, ie no particles, no forces, no dark matter, no energy, no mass, etc, etc, then nothing can change because there is nothing to change. If nothing can change, then time becomes meaningless; there would be no difference between five minutes and five millennia because nothing exists so nothing changes, and there can be no measurements taken, because some sort of ‘clock’ is required. But ‘clocks’ of any sort can’t exist pre-big bang. In this situation, there can be no minutes or millennia.
Perhaps entropy and time are the two sides of the same coin. They both only go one way (I think). It also has to do with black holes, the ‘event horizon’ and singularities at their centre matter is so compressed into an infinitely small ‘region’ - and time and space break down. String theory and ‘Mock theta functions’ (I had never heard of them either) help describe black holes.
At our 2024 Summer Lecture on Black Holes, Dr Adelle Goodwin (the excellent speaker and one of our volunteers) mentioned that inside a black hole space-time is twisted around within the Black Hole, and so nothing can escape, because we can’t escape space-time. I found that a fascinating concept because I had never thought of it like that before, but it makes sense (well, as much sense as anything else does!) A question for another time, might be, ‘if space time twists around and crosses itself, or forms a continuous loop in a Black Hole, what does that mean? If it crosses itself, does that mean present and past exist simultaneously at that point?’ That’s for another time and someone else who doesn’t have to mow a lawn.
Well, the lawn has had a bit more time to grow and so I will need more time to mow it. I certainly haven’t answered the question of ‘what is time’, but I have come up with a hypothesis as to why time can only exist post Big Bang. Whether my hypothesis is consistent with mainstream scientific thought, I have no idea.
My hypothesis, (in one long, tortured sentence), is that, if absolutely nothing exists, then nothing can change, (and the moment a clock of some sort, is snuck in, then it must be ‘post-Big Bang’, because a ‘clock’ is ‘something’ and can only exist post BB) and if nothing changes there can be no entropy; no Entropy means no time.
It’s post Big Bang now, and so the lawn has changed, and I must go and mow it (but maybe I’ll have a cup of tea first).
PS: It occurs to me that maybe almost the same argument could be used to show that space did not exist before the Big Bang. Space requires dimensions, e.g. the distance between us and Alpha Centauri is 4.2 light years; and so it requires a beginning point where there is ‘something’, ‘us’, and an end point, ‘the Alpha Centauri star system’, in this case.
However, there can be no ‘something’ before the Big Bang. If we think in terms of volume for space the same argument applies. There has to be a boundary to the space. Except when we think of the volume of space as being infinite we can take subsets of noninfinite volumes. How can we think of space as having boundaries if there is no way of placing markers to define this non-infinite volume, because nothing can act as a marker before the Big Bang.
I’ve changed my mind, mowing the lawn would have been easier. But I will still have my ‘cuppa’ first.
by Jodie Sims
In the vast expanse of the cosmos, where mysteries abound and questions outnumber answers, Netflix’s latest venture, ‘3 Body Problem’, emerges as a compelling exploration of humanity’s place in the universe. Adapted from Liu Cixin’s acclaimed novel series, this ambitious production delves deep into the realms of science fiction while intertwining elements of hard science and philosophical inquiry.
Liu Cixin’s ‘3 Body Problem’ trilogy serves as the foundational source material for this gripping TV series. Set against the backdrop of China’s Cultural Revolution and spanning across decades, the narrative weaves together a tapestry of complex characters, intricate plotlines and mind-bending concepts.
At its core lies the enigmatic ‘three-body problem’, a mathematical puzzle that symbolises the unpredictable nature of celestial mechanics and serves as a metaphor for the unpredictability of human destiny.
The ‘three-body problem’ refers to a classic conundrum in celestial mechanics wherein the gravitational interactions between three celestial bodies are examined. While the two-body problem (such as the Earth orbiting the Sun) can be solved using Newton’s laws of motion and gravity the addition of a third body introduces complexity that defies straightforward analytical solutions.
In essence, the challenge lies in predicting the future motion of three mutually interacting bodies under the influence of gravity.
The gravitational pull exerted by each body on the others constantly changes their trajectories, leading to highly chaotic and unpredictable behaviours over time.
Mathematically, the equations governing the motion of three bodies are notoriously difficult to solve analytically. Unlike the two-body problem, where solutions can be expressed in terms of simple elliptical orbits, the three-body problem typically requires numerical simulations or approximations to determine the behaviour of the system accurately.
One famous example of the three-body problem’s complexity is the case of the Sun, Earth and Moon. While we can accurately predict the motion of the Earth around the Sun and the Moon around the Earth, predicting the long-term behaviour of the Earth-Moon-Sun system becomes increasingly challenging due to their mutual gravitational interactions.
Central to both the novels and the TV adaptation are themes of contact with extraterrestrial intelligence, which brings us to the forefront of scientific inquiry into the existence of alien life. This exploration naturally leads us to confront the Drake Equation and the Fermi Paradox, two pillars of astrobiology and cosmology.
The Drake Equation, formulated by astronomer Frank Drake in 1961, attempts to estimate the number of active, communicative extraterrestrial civilisations in our Milky Way galaxy. By considering factors such as the rate of star formation, the fraction of stars with planets, and the probability of life evolving on those planets, the equation offers a framework for contemplating the prevalence of intelligent life in the cosmos.
However, the Fermi Paradox casts a shadow over the optimism of the Drake Equation. Named after physicist Enrico Fermi, this paradox succinctly asks: ‘Where is everybody?’ Despite the seemingly high probability of extraterrestrial civilisations, we have yet to detect any conclusive evidence of their existence. This disjunction between the expected abundance of alien life and the lack of observable contact fuels a plethora of speculative theories and hypotheses.
One of the pivotal moments in the series occurs when an unexpected signal from deep space triggers a frenzy of scientific investigation and existential contemplation. This signal, reminiscent of the renowned ‘Wow!’ signal detected in 1977 by astronomer Jerry R. Ehman while working on a SETI project at Ohio State University’s Big Ear radio telescope, lasted for 72 seconds and displayed characteristics suggesting potential extraterrestrial origin.
Named for Ehman’s handwritten exclamation ‘Wow!’ on the data printout, it serves as a beacon of possibility, hinting at the intriguing prospect of contact with intelligent life beyond our solar system. As one of the main characters races to decode its enigmatic message, she grapples with profound questions about humanity’s cosmic significance and the repercussions of encountering a distant civilisation, shaping a pivotal moment in the series.
As ‘3 Body Problem’ unfolds, viewers are invited to ponder these existential questions and wrestle with the implications of our place in the universe and what contact with another world may mean for humanity. Yet, amidst the cosmic contemplations, the series also delves into the realm of speculative science, prompting viewers to consider hypothetical means of interstellar travel.
Without giving too much away, in summary, Netflix’s ‘3 Body Problem’ offers a thoughtprovoking blend of gripping storytelling, scientific inquiry and philosophical musings. By delving into the intricacies of the three-body problem, grappling with the mysteries of the cosmos, and envisioning the possibilities of interstellar travel, the series invites viewers on an intergalactic odyssey that transcends the boundaries of space and time. Whether you’re a fan of hard science fiction or simply intrigued by the enigmas of the universe, this captivating series promises an unforgettable journey into the unknown.
Perth Observatory is a member of the Global Meteor Network, and we now have seven cameras recording the night sky. These state-of-the-art cameras capture meteors, satellite passes and other celestial events, providing us with a unique view of the Solar System’s formation and evolution.
The footage captured by these cameras is not only valuable for scientific research but also for public viewing. You can watch live images from the cameras at night, which update every three minutes during the night. Additionally, we’ve made available condensed footage from the previous night, highlighting every meteor detection. Be warned, it’s hard not to get hooked on watching these videos.
By Dr Craig Bowers
During my time as the POBS/POVG Historian researching the Perth Observatory’s history, I have come across many artefacts that predate the Perth Observatory’s 1896 foundation.
How did we end up with a photographic glass plate from 1882 when the Astrographic telescope did not arrive until 1899?
How did we end up with photographic glass plates of Comet Gale from the Cape Observatory?
How did we end up with a telescope from the 1880s in England, then Queensland, then Mt Stromlo, Mt Bignar and responsible for the location of Siding Springs and finally, the University of Western Australia
How did we end up with Meteorological books and a Day Book from the WA Lands and Survey Department?
As you all know, the Perth Observatory formally dates to September 1896, so how do we have records from 1882 as a starter?
In the beginning, daily activities, finances and communications of the Perth Observatory were recorded in wonderful leather-bound books called ‘Day Books’ or ‘Letter Books’ for most Government Departments like this one.
During a recent scanning project, I came across a Day Book from 1882. So, how? Why?
The Perth Observatory was formed off the back of the Survey Office in 1829, when initially we were the Swan River Colony and later Perth City. The Survey Office changed over the years to end up today as Landgate. However, from April 1828 onwards, it recorded meteorological readings for the State as part of its duties. As the requirements of surveying increased and WA residents registered complaints regarding meteorological reports and predictions, the then WA Crown Lands and Surveys Department formed a dedicated Meteorological Branch in 1873, which carried on until the Perth Observatory took over the meteorological role in 1896.
The first scan shows one of the pages for the meteorological outstation of Geraldton, WA. By 1903, we had 45 towns recording the weather. The writing appears smeared, see second scan, but a result of the use of highly corrosive Iron Gall ink on the paper, making reading sometimes impossible. My next job is to investigate improving the readability of the images. The signature is Mr Robert Cecil Clifton, Chief Clerk for the WA Lands Department in 1880 and Under Secretary in 1891 until retirement in 1918.
This book is the only copy!
Leather, book binding, gold leaf, handmade paper, the smell, Arh!
By Louise Kaestner
Albireo - Beta Cygni:
Are they really together, or are they just sitting next to each other? This double binary is found to our North, dazzling viewers with their striking colour difference. Albireo, the beak star, in the constellation of Cygni, may or may not be bound by gravity. The star is called a double binary because the 2 stars seem close to each other and are gravitationally bound.
The more interesting facts of Albireo lie less in the star itself and more towards the constellation it decorates. It is a well-known fact, mythically speaking, that our darling Grecian God, Zeus, did love the ladies. Back in the day, the Gods didn’t have an app called Tinder. However, they were still able to transform into mysterious creatures, thus creating their fake profiles in the sky. With this profile, Zeus wooed many a maiden, and some missuses. That’s one story. Another revolves around the myth of Orpheus, who was transformed into a swan after a vicious murder. Lyra, a constellation next to Cygnus, is said to be his lyre.
Then there is Phaethon, who may have had a bit too much ambrosia and couldn’t quite drive his chariot straight. Zeus smacked him down with a well-placed bolt and left Phaethon’s lover, Cygnus, weeping and searching for his grave. The Gods felt bad and transformed Phaethon into a Swan, placing him amongst the stars. The Chinese also entertained their own mythology of the Milky Way being a river and Cygnus as a bridge.
Dumbbell Nebula - M27 and NGC6853:
This is a planetary or emission nebula shaped like a Dumbbell. This nebula is visible in our North. This sort of nebula has nothing to do with a planet, nor is it the normal kind of nebula that acts as a stellar womb. Instead, it is the opposite. It is a star graveyard. This kind of nebula forms after the star dies. It is made up of the shell material from the once living star. The shell of gases emitting from the star is why these planetary nebulae are called emission nebulae.
The Dumbbell Nebula was the first planetary nebula ever discovered by Charles Messier. The star emitting the gases isn’t a big star. Rather, it is a white dwarf. It’s also not an old star. Its estimated age is about 3500 years old. The Dumbbell Nebula is bright, which means you should be able to see it even with binoculars. If you want to find it without help, sight your peepers on Cygnus and Aquila, both large constellations. Then, narrow it down to Lyra, Delphinus and Sagitta. Finally, you’ll find the Dumbbell Nebula in the Vulpecula constellation nestled within the above constellations.
By Louise Kaestner
What is not to love about a planet that delivers hard lessons and divine justice? When we talk about skating on thin ice, it’s all about Saturn and its rings, which are now side on to Earth. Saturn is his Roman name. He is known as the God of harvest and time, Chronos, in Roman and Greek mythology. In Hindu mythology, Saturn is known as Shani and the God of Karma. However, he isn’t unjust. Though injustice may reign for a while, he always collects his due.
The rings are what draw the eye to this awe-inspiring and soul-shattering sight. They surround the planet from 7000 – 80000 kilometres above, and they are made of ice and dust. The rings go edge on every 14 and a half years, and that is the point where we are at. Galileo thought the rings were moons because his telescope was low-powered. It wasn’t until 1655, when telescopes had a bit more juice, that astronomers confirmed the rings.
47 Tucanae - C106 and NCG104:
47 Tucanae is circumpolar and found in the constellation of Tucana, otherwise known as the Toucan. 47 Tuc is the second-brightest globular cluster after Omega Centauri. The cluster is home to about a million stars. Globular clusters are stars, bound tightly through gravitation, ranging from the tens of thousands to the millions. They are stable because they are thus bound. Due to the gravitational pull of the stars in the cluster, the clusters tend towards a spherical. However, when you’ve seen one, you have not seen them all. It’s great fun to start counting the stars when you feast your eyes upon them. I get to 5 and go, yeah, nah.
The Toucan is not an ancient constellation. Rather, Dutch astronomer Petrus Plancius decided on the creation of this constellation based on 16th-century sailors Frederick de Houtman and Pieter Dirkszoon Keyser. Within the constellation are many remarkable deep sky objects keeping 47 Tucanae company, such as the Tucana Dwarf galaxy, other globular clusters, and the Small Magellanic Cloud.
By Louise Kaestner
Sculptor Galaxy - Silver Dollar Galaxy, Silver Coin Galaxy, C65 and NGC253:
The Sculptor Galaxy is the second easiest galaxy to view after the Andromeda galaxy. Caroline Hershcell discovered it in 1783 as she searched for comets. The Silver Dollar galaxy is found in the Sculptor constellation, and the galaxy is a barred, or starburst, galaxy. It remains in the company of galaxies grouped around the south galactic pole. Together, the group of galaxies are called the South Polar Group.
The Silver Dollar Galaxy is considered a barred, spiral galaxy because it has spiral arms stretching out from the centre in a semi-circle, hugging the middle. The galaxy is also considered a starburst galaxy because of the large number of stellar nurseries where hot, young blue stars are born. These young stars emitting radiation are what give this distinctive galaxy, easy to see through binoculars, the beautiful colours.
Pleiades - M45, 7 Sisters or Brothers, Subaru, and Matariki:
The Pleiades, an open cluster in Taurus, is visible to the naked eye and steeped in ancient myth. However, to appreciate its worth, one should view it through binoculars or a telescope and dive deep into its history. The ancient Greeks derived their myth around this cluster due to its importance in denoting the season it was safe to sail. Even the Noongar and Indigenous tribes of Australia had detailed myths around this cluster. In 250 million years, or another rotation of our Milky Way Galaxy, the cluster will no longer be. The myths surrounding them will be naught but ancient history.
Open clusters are not as big as globular clusters. However, open clusters are born from the same molecular cloud or stellar womb, like globular clusters. They are bound through gravitation to each other. However, it is a bond more like distant relatives than close siblings. These clusters tend to be on the young side and are prone to instability due to the tidal forces of the galaxies they reside in. As the Milky Way rotates, the stars in the cluster encounter other clusters and clouds of dust, dispersing in the process.
Help Perth Observatory through the Containers for Change scheme.
Please take glass, plastic, aluminium, steel, and paper-based cartons between 150ml and 3L to your local refund depot and use the Perth Observatory (Scheme ID: C10424615).
The Perth Observatory Volunteer Group will receive 10 cents for each container. Save the ID on your phone for every time you recycle your containers. Find your local refund depot and get more info on what containers are eligible for refunds here:
Can’t get to a refund centre? We have a dedicated and labelled bin on-site for you to add your clean container donations when you next visit the observatory.
Our maintenance volunteers collect donated containers and take them to the refund centre.
Thank you for helping the POVG promote sustainable and environmentally conscious practices and diversifying ways for us to raise much-needed funds.
Your help supports the continuing upkeep and running of Western Australia’s oldest observatory!
