OAS Newsletter April 2016
Contents Page 3. Planetary Positions Page 4. Lunar Occulations Page 5. Meteor Showers Page 6. Deep Sky Objects Page 7. Binocular Tour
Our new Diploma in Astrophysics and Space Science Please click here to learn more https://issuu.com/oasacademy2/docs/ass_brochure
Planetary Positions Mercury – puts on its best evening appearance of the year this month and it reaches greatest eastern elongation on 18th April. It is brightest at the start of the month, when it will be at mag -1.5, then fades to mag +2.8 by the end of April. It is visible for about 45 minutes after sunset (between 9pm – 10pm), above the west-north-west horizon. On 8th April, Mercury lies close to the 1 day old Waxing Crescent Moon; binoculars will help you to see this conjunction. Towards the end of the month, look for Mercury near to M45 the Pleiades star cluster Venus – is not easily visible this month as it is very close to the Sun Mars – located on the borders of Scorpius & Ophiuchus, Mars brightens from mag -0.5 to -1.5 during April. It rises just before midnight, then remains visible above the southern horizon until dawn. On 17th April it reaches a stationary point at 3am; then it begins another period of retrograde motion. It remains close to Saturn all month, forming a triangle with the red giant star, Antares. On 25th April, the Waning Gibbous Moon lies near to Mars, Antares & Saturn
Jupiter – dominating the evening sky at mag -2.2, you can’t fail to spot magnificent Jupiter below the stars of Leo. It remains visible all night, setting at around 5am. On 7th April, Jupiter passes just north of Chi Leonis. On 17th April, the Waxing Gibbous Moon lies close to Jupiter Saturn – located in Ophiuchus and rising at around half an hour after Mars, is the slightly duller Saturn at mag +0.4. It remains close to Mars all month, forming a triangle with the red giant star, Antares. On 25th April, the Waning Gibbous Moon lies near to Mars, Antares & Saturn. On 26th April the Waning Gibbous Moon lies near to Saturn Neptune – keen observers may catch a glimpse of mag +7.9 Neptune before dawn. Located in Aquarius and rising at 5am, it is visible very low in the east Uranus – is not visible this month
Lunar Occultation of Hyades – on the evening of 10th April, the Waxing Crescent Moon occults several stars of the Hyades star cluster in Taurus, principally Theta1 and Theta2 Tauri. The stars
will disappear behind the darkened limb of the crescent Moon and reappear from the illuminated side. The occultation times vary depending on location, but the approximate times are as follows:
Meteor Showers Lyrids Meteor Shower This shower is active from 16th – 25th April, with its peak on 22nd April. It has a zenith hourly rate of around 10 meteors per hour. However, the Full Moon will severely hamper observations, with only the brightest meteors being visible GCSE Astronomy by distance learning Interested in gaining a qualification with Online Astronomy Society Academy? Why not enrol on our GCSE Astronomy program. For only £180 we provide 24/7 access to online portal Textbook Online worksheets Study planner Tutor support Even final exam
Deep Sky Objects This month’s Sky at Night Magazine Deep Sky Tour is centred on several galaxies which can be found in the sky near Canes Venatici. With a small or medium telescope, look for NGC 4656 & NGC 4657 which are jointly known as the Hockey Stick Galaxy. Northwest of the Hockey Stick is NGC 4631 the Whale Galaxy, with the faint dwarf elliptical galaxy NGC 4627 just above it. Also visible with a small or medium telescope is NGC 4214, a dwarf barred irregular galaxy. Just 1.5 degrees north of NGC 4214 you will find NGC 4244, an edge-on galaxy. Finally, if you have a large telescope, look for the Seyfert spiral galaxy NGC 4395, which contains several bright patches. For full details of where to find these objects, pick up the April issue of Sky at Night magazine
Binocular Tour This month’s Sky at Night Magazine Binocular Tour focuses on the area around Cancer. With 10x50 binoculars, look for M44 the Beehive Cluster. A favourite imaging target, M44 is a naked eye visible open cluster containing over 1,000 stars. M44 is framed by an asterism called the Manger. Also with 10x50s, look for the asterism called the Little Crab, which spans nearly 7 degrees, the open cluster M67, and the asterism within Hydra called Hydra’s Head which contains stars with a variety of different colours. If you have 15x70 binoculars, look for the double star Iota Cancri which contains a mag +4.0 yellow giant and mag +6.0 white main sequence star. Finally, look for the open cluster M48. In 15x70 binoculars you should see more than a dozen stars against a background of fainter ones. For full details of where to find these objects, pick up the April issue of Sky at Night magazine M101 The Pinwheel Galaxy - Astronomy Now’s Object of the Month is M101. It is a face-on spiral galaxy with well-defined arms. It is in the circumpolar region of Ursa Major, just above the “handle” of the Plough. During April it is best placed for observation because it
is almost directly overhead. Although its magnitude is +7.9, it has a low surface brightness so even with a 70mm telescope, it will only be a small hazy smudge and probably only visible with averted vision. A telescope of 200mm or larger with high power eye pieces will reveal more structure. Good transparency & seeing are essential. If you want to photograph it, it responds well to LRGB imaging with a CCD camera but you can also get good results with a DSLR. Narrowband imaging a with narrowband hydrogen alpha filter will help to bring out the HII regions and give even better results. For more information on how best to observe and image this object, take a look at the April issue of Astronomy Now magazine Solar Observations – now that the days are longer than the nights and the Sun is getting higher in the sky, it is the ideal time to begin the new season of solar observations. A white light filter will show sunspots, faculae and maybe some granulation. A specialist hydrogen-alpha telescope will show filaments, prominences and if you are lucky you may catch a solar flare in action SAFETY WARNING: Never attempt to observe or photograph the Sun without the correct equipment.
Failure to do so will result in permanent damage to your eyes or even blindness! Comets Visible This Month: Comet 252P/LINEAR – currently at mag +9, it moves up through Ophiuchus during April. At the beginning of the month it rises at round 2:30am in the south west and remains visible low in the south-south-west until dawn. By the end of the month it will be visible about 20 degrees above the eastern horizon at dusk, then remains visible until dawn. Click here to view the finder chart: http://bit.ly/1RHyPBk Comet C/2013 US10 Catalina – currently at mag +10.4 and fading, it is located in Perseus this month. It becomes visible at dusk when it is located about 50 degrees above the north western horizon, then remains visible until dawn, when it will be very low in the north. Click here for the finder chart: http://bit.ly/1RZwvYI Comet 81P/Wild – at mag +10.8, it starts the month in Taurus then moves into Gemini. It becomes visible after dusk, when it is located 49 degrees above the
south west horizon. It then sinks towards the horizon and sets at around 2:30am. Click here to view the finder chart: http://bit.ly/21R08Pm For up to date information about the comets visible this month, please visit https://in-thesky.org/data/comets.php, the BAA Comets Section: https://www.ast.cam.ac.uk/~jds/ or Seiichi Yoshida’s home page: http://www.aerith.net/index.html NB: All of the above information is taken from Night Scenes 2016 by Paul L Money, Philips Stargazing 2016, Astronomy Now Magazine, Sky at Night Magazine, Stellarium, the BAA Comets Section website https://www.ast.cam.ac.uk/~jds/, www.inthesky.org and Seiichi Yoshida’s home page: http://www.aerith.net/index.html Information collated by Mary Spicer