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The Eclipse of Dec 10, 2011 It’s the last lunar eclipse of 2011 . Don’t miss it for anything!

Its winter season in Delhi. The weather is at its best and so are the heavens. Winter is arguably the best time in the year when observational astronomy is a pleasurable activity to indulge yourself in the NCR region. No more mosquitos after the monsoon showers and no more sticky and sweltering weather to bear. So grab your binoculars as the Moon enters the earth’s umbral shadow on December 10th 2011. Plus its Saturday evening. What better way to relax with your better half (or more than half ;) ) than to gaze at the moon that night. The eclipse will be a rather long event slated to begin at 6:02 pm in the evening with the deepest umbral phase at around 8pm IST. During the eclipse moon will be in Taurus in the eastern sky. You can also join the festivities with the AAAD. The AAAD, in conjunction with Nehru Planetarium, New Delhi will be organizing a grand observation from the sprawling Teen Murti Lawns. There will be plenty of big binoculars and telescopes to watch the moon and the planets that night.

Location of Moon in Taurus during the December 10, 2011 Lunar Eclipse


Simply Spectacular: A brilliant image of the grandeur of the winter milky way through Orion. Photo courtesy AAAD member Ajay Talwar, Turn to page 4 for photographers notes


Photography Notes: By Ajay Talwar

HIDDEN EARTH

This photo is special in a way. I

Did you know that Saturn’s moon Titan is very similar to earth having a dense earth like atmosphere. Although it’s a bit chilly there (-180 °C), who knows what surprises may lurk under the ice.

have a very old Pentax lens 50mm f/1.2, the lens is called normal (when talking about 35 film format), but it is actually ab -normal because of it's fast fratio of 1.2. The lens had cost me a lot, more than the pentax

EPHEMERIS

camera body. It had been used

1.12.2011: Venus is 5°.4’ degrees South of Pluto

sparingly and soon after I start-

1.12.2011: Neptune is 6°.1’ South of Moon

ed digital. I came to know about

2.12.2011: Moon is at greatest latitude 5°.15’ North

an adapter that will connect the Canon body and Pentax lenses

2.12.2011: Moon reaches its first quarter

and further it will also provide

4.12.2011: Mercury is in inferior conjunction 1°.16’ North of Sun

feedback

5.12.2011: Mercury is in perihelion

about

focusing.

I

bought the adapter and this photograph was the very first result of the combination.

5.12.2011: Jupiter 5°.2’ south of Moon 10.12.2011: Full Moon: LUNAR ECLIPSE 13.12.2011: Geminids Peak

The sub-exposure in this image is 45 seconds at ISO 1600, and amazingly it has captured the

17.12.2011: Mars is 8°.5’ North of Moon 18.12.2011: Last Quarter of Moon

faint Barnard's Loop in Orion.

20.12.2011: Saturn is 6°.5’ South of Moon

No doubt being at the Indian

22.12.2011: Moon at perigee

Astronomical

Observatory

at

Hanle helped a lot in easily capturing the Barnard's Loop. I shot

24.12.2011: New Moon 27.12.2011: Venus is 6°.4’ South of Moon

plenty of sub-frames for this im-

5.01.2012: Quadrantids Meteor Shower, peaks of 40 per hour

age - 367 in number, that's

9.01.2012: Full Moon

about 4.5 hours of shooting. Ac-

23.01.2012: New Moon

tually the purpose of shooting so many frames was to make a movie

of

the

Geostationary

Highway, the resultant movie is

You can now follow us on

here: http://youtu.be/p4Q10hHcqjU?hd=1

http://www.twitter.com/ aaadelhi


Great Observatories: The Search for Gravitational Waves

Continued from page 1...

When large masses move suddenly, some of this space-time curvature ripples outward, spreading in much the way ripples do the surface of an agitated pond. Imagine two neutron stars orbiting each other. A neutron star is the burned-out core often left behind after a star explodes. It is an incredibly dense object that can carry as much mass as a star like our sun, in a sphere only a few miles wide. When two such dense objects orbit each other, space-time is stirred by their motion, and gravitational energy ripples throughout the universe. In 1974 Joseph Taylor and Russell Hulse found such a pair of neutron stars in our own galaxy. One of the stars is a pulsar, meaning it beams regular pulses of radio waves toward Earth. Taylor and his colleagues were able to use these radio pulses, like the ticks of a very precise clock, to study the orbiting of neutron stars. Over two decades, these scientists watched for and found the tell-tale shift in timing of these pulses, which indicated a loss of energy from the orbiting stars -- energy that had been carried away as gravitational waves. The result was just as Einstein's theory predicted.

How LIGO Works LIGO is an acronym for Laser Interferometer Gravitational wave Observatory. LIGO is designed to detect the ripples in space-time by using a device called a Michaelson interferometer, in which the time it takes light to travel between suspended mirrors is measured with high precision using controlled laser light. Two mirrors hang far apart, forming one "arm" of the interferometer, and two more mirrors make a second arm perpendicular to the first. Viewed from above, the two arms form an L shape (cover photo). Laser light enters the arms through a beam splitter located at the corner of the L, dividing the light between the arms. The light is allowed to bounce between the mirrors repeatedly before it returns to the beam splitter. If the two arms have identical lengths, then interference between the light beams returning to the beam splitter will direct all of the light back toward the laser. But if there is any difference between the lengths of the two arms, some light will travel to where it can be recorded by a photodetector.


The Great Orion Nebula (M42), Photograph courtesy Deepak Dogra, Nikon D90. Sigma 120-400@400mm. ISO800. f7.1. Stack of various exposures: 3x5min, 7x3min, 8x2min, 15x1min. Astrotrac.


We know that any mass bearing object is able to displace spacetime, the amount being directly related to the mass of the object. This is pretty similar to how you warp your mattress when you sleep on it! The motion or sudden change of this mass can sat up a ripple in spacetimeo or your mattress. LIGO hopes that a passing gravity wave would cause the “relative� length of the two arms to change and hence be recorded as an interference pattern. In principle, this is a pretty simple process. However differentiating real data from noise is a big engineering challenge. LIGO is affected by earthquakes, air turbulence, and is sensitive enough to pick up vibrations from man made activities several miles away!

This picture shows how gravity can bend spacetime. Light appears bent under the influence of gravity. The truth it is gravity bends the very fabric of space and hence light appears bent!. Image courtesy NASA

XKCD: THE IMPORTANT FIELD

LEARN HOW TO TAKE SUNSPOT PHOTOS Learn how to take great images of the solar disc by this great tutorial by Anindya. Follow the link below or point your smartphone to the QR code

http://tinyurl.com/853nkky


True . . . Space is more enormous than what hu-

What is very interesting is what the human imagi-

man imagination can ever fathom but that has not

nation makes of these constellations. Each differ-

stopped humans over the centuries from trying to

ent culture developed its own set of interpretation

imagine as well as comprehend what lies beyond.

for the same constellation, which was a reflection

All over the world, consciously or unconsciously,

of their environment and times.

people have made the universe a part of their daily lives. Since the Stone Age, the sky has shaped

One good example is the Big Dipper, an asterism

the human past and continues to influence us

(pattern) of 7 stars and part of the much bigger

still. Be it agriculture, navigation, architecture,

constellation of Ursa Major or the Big Bear. Alt-

art, science or even religion and God – the an-

hough most see it as a dipper or a question mark,

swers to all such things had its origins in the sky .

the Chinese see it as a wheel barrow, since they invented it; the people of the Middle East see a

If you raised your eyebrow at that last sentence,

hearse (since they witnessed a lot of deaths in

think again. When ancient man looked heaven-

wars and violence); for North American Indian

wards he learnt that all things on earth die but the

tribes, the bowl of the Big Dipper is a bear, and

sun, moon, and stars survive night after night,

the stars in the handle represented hunters track-

month after month, year after year. Their absenc-

ing the bear; the British call it a Plough; and the

es are only temporary. They started to think of

ever-gastronomic French see a sauce-pan (how

these celestial objects as eternal entities and thus,

predictable). Indians call it the Sapt Rishi and in

was born the concept of the immortal God. The

certain Hindu weddings, it is customary for the

various world religions took time to evolve but it

newly-weds to see the stars Alcor and Mizar, who

all started with myths and legends associated with

represent the faithful Arundhati and her husband

the heavens.

Sage Vasistha respectively.

It is interesting to note that across the ancient world all cultures saw the sky as either the dwelling place of gods (the heaven). Certain unexplainable things like thunder and lightening got associated with the king of gods. Thus, the Greeks

Interestingly, in 19th century USA, the Big Dipper

thought that Zeus, king of the Greek pantheon of

became a symbol of freedom for runaway slaves

gods, hurled a bolt of lightening when angry.

from the South before the Civil War. Since a ma-

While the Romans thought the same about Jupi-

jority of the slave population was illiterate, there

ter. Likewise, Thor was the Viking Norse god of

were songs with veiled messages and references to

thunder and rain. Even Hindu mythology says

follow the ‘Drinking Gourd’ for a better life.

that Indra’s astra (weapon) was the thunderbolt. Many cultures believed that the positions of the

The Big Dipper pointing towards the Pole Star at

stars were their God's way of telling stories. So it

the north was not only the guiding light for runa-

seemed natural to recognize patterns in the sky,

way slaves but was used extensively historically by

give them names, and tell stories about them.

sailors for navigation.


The Phoenicians, who were the first enterprising

the prehistoric megaliths of Stonehenge, the medi-

Mediterranean

civilization

cine wheels of North America, the Aztec ‘Calendar

around 1550 BC to 300 BC, must have used the

Stone’ and prehistoric observatories such as the

stars to navigate their way to Greek ports of the

megalithic Kintraw monument in Scotland were

time. There they learnt about the Greek mythologi-

used for the practical applications of farming by

cal legends and used these to name the constella-

measuring time and seasons using the sun and

tions for easy use. And till this day we have con-

stars. Thus, astronomy went on to play a much

stellations named after Perseus and his winged-

greater role in agriculture, engineering and archi-

horse Pegasus, Orion the hunter and his nemesis

tecture. Later in the course of human history,

Scorpius, and many more scattered in the northern

many more archaeological sites such as Mayan

skies. New constellations were formed by sailors

temples, Chinese tombs, Egyptian and Mexican

south of the equator where the Pole Star is not visi-

pyramids also illustrate the profound connection

ble. Since people started venturing to the southern

between celestial phenomena and human beliefs.

seas only during the 18th century, most of the con-

The great pyramids of the Egyptian pharaohs were

stellations were named after objects that came into

supposed to be monuments which facilitated

prominence around the Industrial Revolution.

man’s ascent to the divine. However, there were

Thus, we have Fornax (Latin for furnace), Caelum

also certain monuments erected only for astro-

(Latin for chisel), Horologium (Latin for clock),

nomical purposes, such as the four Jantar Mantars

Microscopium (named after the Microscope), and

in India.

maritime

trading

Octans (named after the octant, a navigational instrument).

The astronomical bodies also aided artists in their flights of imagination. The effects of light at night

The stars and the constellations have thus, helped

provided the subject for some of Dutch post-

in the discovery of new countries like the Americas

impressionist artist Vincent Van Gogh’s most fa-

and Australia, which in turn facilitated coloniza-

mous paintings. He painted star-filled skies in Star-

tion by the Europeans and the subsequent spread

ry Night over the Rhone, Cafe Terrace at Night and

of their culture.

his magnum-opus Starry Night.

The regularity of the motions of celestial objects

While the stars inspired Van Gogh to paint Starry

enabled our ancestors to orient themselves in time

Night, his painting became the inspiration for

and space, satisfying their need for human order.

French composer Henri Dutilleus’s orchestral work

The ancient people learnt about the changes in the

Timbres, Espace, Mouvement, American poet Anne

season from repeated observation of the night sky.

Sexton’s poem The Starry Night, Canadian compos-

Orion heralded winter, while the Summer Triangle

er Giancarlo Scalia’s piano composition Starry

was the harbinger of summer or spring. The con-

Night and for Don McLean’s song Vincent, which is

stellations made it easier for the farmers to plan

also known by its opening words, "Starry, Starry

ahead and form the science of agriculture.

Night."

Most ancient civilizations used astronomical calendars to sow and reap their crops. Many believe that


It’s not Van Gogh’s Starry nights, but this tribute to the masterpiece by Rip Cronk is an central icon in Venice’s streetscape.


Likewise, the great unknown spawned an entire

ter’s song Calling Occupants of Inter-Planetary

generation of science fiction literature (The Time

Craft. Pink Floyd wrote a number of space-

Machine, The Hitchhiker’s Guide to the Galaxy,

themed songs like Astronomi Domine and

Cosmos, A.I. to name a few) and authors such as

Eclipse, and they have also been played time and

H. G. Wells, Jules Verne, Carl Sagan, Issac Asimov

time again in outer space. Russian astronauts took

and Arthur C. Clarke ignited the imagination of

a recording of their album Delicate Sound of

common man to think beyond the normal. By the

Thunder, into space with them. Similarly, the late

1970s, sci-fi movies and the popular TV series,

Kalpana Chawla took Deep Purple’s Space

such as Star Wars and Star Trek, gave a more con-

Truckin’ and The Aviator as her wakeup music on-

crete shape to what the human mind had imag-

board Columbia. Likewise, the great unknown

ined about extra-terrestrial life forms in galaxies

spawned an entire generation of science fiction

far, far away.

literature (The Time Machine, The Hitchhiker’s Guide to the Galaxy, Cosmos, A.I. to name a few)

In conclusion, one can say that astronomy was the

and authors such as H. G. Wells, Jules Verne, Carl

first science, which went on to nurture several sib-

Sagan, Issac Asimov and Arthur C. Clarke ignited

lings (in both sciences and arts). In several African

the imagination of common man to think beyond

cultures, the first words ever spoken to a newborn

the normal. By the 1970s, sci-fi movies and the

child is under the open starlit sky by the father

popular TV series, such as Star Wars and Star

who lifts the baby skyward and says: “Behold at

Trek, gave a more concrete shape to what the hu-

the only thing that is and always will be superior

man mind had imagined about extra-terrestrial

and greater than you.” The universe and astrono-

life forms in galaxies far, far away.

my is definitely superior and greater than our grasp, as well as the only thing that stays constant,

In conclusion, one can say that astronomy was the

yet ever-changing from our birth till our death.

first science, which went on to nurture several siblings (in both sciences and arts). In several African

Poets and song writers have always been intrigued

cultures, the first words ever spoken to a newborn

by the night sky. There are numerous songs in all

child is under the open starlit sky by the father

Indian languages that use the moon and the stars

who lifts the baby skyward and says: “Behold at

as metaphors. In fact, modern day songsters re-

the only thing that is and always will be superior

peatedly use the celestial bodies for appreciation

and greater than you.” The universe and astrono-

of beauty and an expression of love. But many

my is definitely superior and greater than our

have also written solely about the wonder of space

grasp, as well as the only thing that stays constant,

and what lies beyond, such as Boney M’s ballad

yet ever-changing from our birth till our death.

about 10000 Light Years Away and The Carpen-

Photo: J. Stoop


The instruments of the Jaipur Observatory are better maintained, and their usage for a gathering of a database of astronomical observations to characterize the instruments, is a more easily feasible project. The basic structures of the Jantar Mantar instruments are yet reasonably preserved. Whatever damage has happened to the instruments is mostly surface damage which can be repaired. The Jaipur instruments are the best maintained, although, there are concerns with respect to the maintenance, condition and sustained usage of all the four Jantar Mantar observatory instruments those at Delhi, Jaipur, Varanasi and Ujjain.

A view of the Chakra Yantra of the Jaipur Observatory, with the Equinoctial sundial the Laghu Samrat Yantra in the background.

The Observatories have the potential to be a live teaching laboratory. Any modern day student of

three months, to make a temporary observational

Astronomy and Astrophysics would need to know

calibration of the Samrfestival was then held on the

the basics of positional Astronomy, and would do

Winter Solstice day where time measurements ob-

that learning very well, from these observatories.

tained by the visitors and school students were

The Samrat Yantra, an equinoctial sundial, was

compared with a clock set to 1 second accuracy

evolved into a serious positional astronomy instru-

with kind help from the National Physical Labora-

ment by Sawai Jai Singh, and was installed by him

tories, New Delhi. at Yantra, for every minute.

in each of the Jantar Mantar Observatories that he had built. The largest at the Jaipur Observatory and the second largest at the Delhi Observatory, were both marked at some time, with a least count of 2 seconds for measurement of time. There have been serious criticisms of realistically achieving this accuracy, given the uncertainty in shadow reading from the penumbra. However, in December 2006, it was practically demonstrated for the Samrat Yantra of the Delhi Observatory that achieving 1 second accuracy in time measurement is a feasibility even in its current state of dis-

The Misra Yantra of the Delhi Observatory is a unique teaching instrument for positional Astronomy, thought to have been built, not by Sawai Jai Singh, but, by his son Madho Singh, who also had some astronomy interest. The most recognized aspect of this instrument is the arched marble Niyat Chakra which defines its front elevation. These measure the Declination (angular distance from the celestial equator) of the Sun and other celestial objects in a beautifully simple manner.

repair, absence of markings and presence of so

The other functionalities of the Misra Yantra in-

many masonry irregularities.

clude time measurements similar to the Samrat

This demonstration was made by a group of observers from the Nehru Planetarium, New Delhi and amateur astronomers, working over a period of

Yantra, measurement of Meridian Altitudes using the Dakshinottara Bhitti Yantra and the measurement


of Ecliptic co-ordinates using the Karka Rasi Valaya instrument on the back wall of the Misra Yantra. There are the Ram Yantra instruments of the Delhi and Jaipur observatories which make Altitude and Azimuth measurements of the Sun and celestial objects seem like a fun game being played by children crawling around under the aesthetically pleasing wall and floor sectors of these cylindrical

instruments.

There are the bowl shaped Jai Prakas and Kapala Yantras which can measure celestial

Error in time obtained from using the temporarily calibrated Samrat Yantra

co-ordinates in many different co-ordinate systems and are complete positional astronomy instruments, in some sense. One of the Kapala Yantras at the Jaipur observatory has also a built in capability for theoretical conversions between different co-

in time keeping was achieved around 1720s. At that time, India also had an instrument that was capable of achieving 1 second or even better accuracy in time keeping.

ordinate systems. There is the Chakra Yantra for

For 300 years this fact had not been appreciated in

measuring equatorial co-ordinates of celestial ob-

practice, although theoretical statements about the

jects whose mounting is akin to a modern day

accuracy of these instruments are scattered in all

equatorially mounted telescope.

the guide books. Every day there are hundred of

There is another aspect to be bought out, about the observatories. We have been working with the cali-

visitors passing through the Observatory – not being able to appreciate this practically, even today.

bration of the Samrat Yantra of the Delhi observa-

For this appreciation, a complete restoration with

tory, for its usage as an equinoctial sundial. The

all markings in place is needed for the Delhi Obser-

amazing practical result that we found was that,

vatory. What is also needed is a very large sized

even with very temporary calibration markings

modern day digital clock – set accurate to 1 second

made in chalk, the Samrat Yantra of the Delhi ob-

precision by the National Physical Laboratories –

servatory, is capable of reading time to an accuracy

on display near the Observatories. This clock

of 1 second. With more permanent calibration

should be visible from all the instruments of the

markings, it should be able to better this accuracy.

observatory, and every day’s visitor would then be

This aspect needs to be studied, analyzed and em-

able to appreciate the accuracies of these beautiful

phasized more. The world over, 1 second accuracy

instruments.


Acknowledgements To all the observers without whose patient work, the calibration of the Samrat Yantra could not have been completed – Anurag Garg, Dayal Singh, Ramesh Chikara, K. S. Balachander, Sneh Kesari, Vidushi Bhatia, Vikrant Narang, Pritpal Kaur, Arpita Pandey, Vidur Prakash and many other students and amateur astronomers who lent a hand. To the staff of the Jantar Mantar and the Archeological Survey of India, for their support

ANGELS & DEMONS? Yup!, that was a misleading title. There is nothing demonic about this

Image courtesy: Mike White, New Zealand

picture here. But then what is this strange halo that you see around the moon. This

The big question is why have sightings of moon ha-

winter, when you step outside the house and look

los increased suddenly in recent times? Is it cli-

at the moon, you may yourself bear witness to

mate change? Your guess is as good as mine.

this peculiar sighting. “Moon Halos” or “Moon dogs” as they are called, are a very interesting atmospheric phenomena that occurs during winter time. Moon halos or their daytime

counterparts “sun halos” were virtually

unheard of in India a few years ago. However the number of moon halo sightings has increased recently. Moon haloes are though to be caused by light passing through ice crystals suspended in the sky. A very interesting characteristic of a moon halo is that it is always of the same size. The halo has a 22 degree optical spread. This means that the angle formed between two opposite ends of the halo at the eye is always 22 degrees.


IN THE NEWS AMATEUR ASTRONOMER IMAGES EXTRASOLAR PLANETARY DISC Just when you thought that amateur astronomy could not compete with the pros, a fellow amateur astronomer Rolf Olsen in New Zealand has been able to catch glimpses of a exoplanet system debris around β– Pictoris. In the 1980s an Infrared orbiting observatory called IRAS discovered this disc orbiting β-Pictoris which was later thought to be a planet forming region. Now for the first time ,this disc has been captured in visible light. What Rolf did was pretty simple. He took a bunch of pictures of β-Pictoris (in the southern constellation Pictor), and then a bunch of pictures of α-Pictoris. Then using image processing software he subtracted the two images thus blocking out the overwhelming brightness of the star. It was important that the two stars that were subtracted have to be similar, or the subtraction will not be complete. This method is not what astronomers typically use for exoplanet detection. Typically

Photo © 2011 Rolf W. Olsen. Used with permission The picture above shows the protoplanetary disc around β-Pictoris. The glare from this star is subtracted to reveal the disc. For comparison see the IR image in the inset. (L. D Etangs et. al, 1993 )

exoplanets can be detected using photometry, where a eclipsing planet would cause a periodic dip in the star’s brightness. A second, but more direct approach is to use interferometry. Light from two telescopes can be combined optically to remove the bright starlight. This is what observatories like the W. M. Keck observatory in Hawaii do. The thing to keep in mind is that Rolf did not do this using sophisticated equipment. The picture you see here was produced using a 10 inch truss Dobsonian! On behalf of the AAAD, I would like to congratulate Rolf on this achievement!



Krittika