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 observa-

tional 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. Dur-

ing 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 obser-

vation 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

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EPHEMERIS

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

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

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

2.12.2011: Moon reaches its first quarter

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

5.12.2011: Mercury is in perihelion

5.12.2011: Jupiter 5°.2’ south of Moon

10.12.2011: Full Moon: LUNAR ECLIPSE

13.12.2011: Geminids Peak

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

18.12.2011: Last Quarter of Moon

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

22.12.2011: Moon at perigee

24.12.2011: New Moon

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

5.01.2012: Quadrantids Meteor Shower, peaks of 40 per hour

9.01.2012: Full Moon

23.01.2012: New Moon

This photo is special in a way. I

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 f-

ratio of 1.2. The lens had cost me

a lot, more than the pentax

camera body. It had been used

sparingly and soon after I start-

ed digital. I came to know about

an adapter that will connect the

Canon body and Pentax lenses

and further it will also provide

feedback about focusing. I

bought the adapter and this

photograph was the very first

result of the combination.

The sub-exposure in this image

is 45 seconds at ISO 1600, and

amazingly it has captured the

faint Barnard's Loop in Orion.

No doubt being at the Indian

Astronomical Observatory at

Hanle helped a lot in easily cap-

turing the Barnard's Loop. I shot

plenty of sub-frames for this im-

age - 367 in number, that's

about 4.5 hours of shooting. Ac-

tually the purpose of shooting

so many frames was to make a

movie of the Geostationary

Highway, the resultant movie is

here:

Photography Notes:

By Ajay Talwar

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

You can now follow us on

http://www.twitter.com/ aaadelhi

HIDDEN EARTH

Did you know that Saturn’s moon

Titan is very similar to earth hav-

ing a dense earth like atmos-

phere. Although it’s a bit chilly

there (-180 °C), who knows what

surprises may lurk under the ice.

Great Observatories: The Search for Gravitational Waves

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 ob-

ject 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 puls-

es, which indicated a loss of energy from the orbiting stars -- energy that had been carried away as gravi-

tational waves. The result was just as

Einstein's theory predicted.

How LIGO Works LIGO is an acronym for Laser Interfer-

ometer Gravitational wave Observato-

ry. LIGO is designed to detect the rip-

ples in space-time by using a device

called a Michaelson interferometer, in

which the time it takes light to travel

between suspended mirrors is meas-

ured with high precision using con-

trolled laser light. Two mirrors hang

far apart, forming one "arm" of the in-

terferometer, 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 di-

rect 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.

Continued from page 1...

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This picture shows how gravity can bend spacetime. Light appears bent under the influence of gravity. The truth it is gravi-

ty bends the very fabric of space and hence light appears bent!.

Image courtesy NASA

XKCD: THE IMPORTANT FIELD

We know that any mass bearing object is able to dis-

place 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 pass-

ing gravity wave would cause the “relative” length of

the two arms to change and hence be recorded as an in-

terference 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 turbu-

lence, and is sensitive enough to pick up vibrations

from man made activities several miles away!

LEARN HOW TO TAKE SUN-

SPOT 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-

man imagination can ever fathom but that has not

stopped humans over the centuries from trying to

imagine as well as comprehend what lies beyond.

All over the world, consciously or unconsciously,

people have made the universe a part of their dai-

ly lives. Since the Stone Age, the sky has shaped

the human past and continues to influence us

still. Be it agriculture, navigation, architecture,

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

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

If you raised your eyebrow at that last sentence,

think again. When ancient man looked heaven-

wards he learnt that all things on earth die but the

sun, moon, and stars survive night after night,

month after month, year after year. Their absenc-

es are only temporary. They started to think of

these celestial objects as eternal entities and thus,

was born the concept of the immortal God. The

various world religions took time to evolve but it

all started with myths and legends associated with

the heavens.

It is interesting to note that across the ancient

world all cultures saw the sky as either the dwell-

ing place of gods (the heaven). Certain unexplain-

able things like thunder and lightening got associ-

ated with the king of gods. Thus, the Greeks

thought that Zeus, king of the Greek pantheon of

gods, hurled a bolt of lightening when angry.

While the Romans thought the same about Jupi-

ter. Likewise, Thor was the Viking Norse god of

thunder and rain. Even Hindu mythology says

that Indra’s astra (weapon) was the thunderbolt.

Many cultures believed that the positions of the

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

seemed natural to recognize patterns in the sky,

give them names, and tell stories about them.

What is very interesting is what the human imagi-

nation makes of these constellations. Each differ-

ent culture developed its own set of interpretation

for the same constellation, which was a reflection

of their environment and times.

One good example is the Big Dipper, an asterism

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

constellation of Ursa Major or the Big Bear. Alt-

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

the Chinese see it as a wheel barrow, since they

invented it; the people of the Middle East see a

hearse (since they witnessed a lot of deaths in

wars and violence); for North American Indian

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

the stars in the handle represented hunters track-

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

ever-gastronomic French see a sauce-pan (how

predictable). Indians call it the Sapt Rishi and in

certain Hindu weddings, it is customary for the

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

represent the faithful Arundhati and her husband

Sage Vasistha respectively.

Interestingly, in 19th century USA, the Big Dipper

became a symbol of freedom for runaway slaves

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

jority of the slave population was illiterate, there

were songs with veiled messages and references to

follow the ‘Drinking Gourd’ for a better life.

The Big Dipper pointing towards the Pole Star at

the north was not only the guiding light for runa-

way slaves but was used extensively historically by

sailors for navigation.

The Phoenicians, who were the first enterprising

Mediterranean maritime trading civilization

around 1550 BC to 300 BC, must have used the

stars to navigate their way to Greek ports of the

time. There they learnt about the Greek mythologi-

cal legends and used these to name the constella-

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

stellations named after Perseus and his winged-

horse Pegasus, Orion the hunter and his nemesis

Scorpius, and many more scattered in the northern

skies. New constellations were formed by sailors

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

ble. Since people started venturing to the southern

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

stellations were named after objects that came into

prominence around the Industrial Revolution.

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

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

Microscopium (named after the Microscope), and

Octans (named after the octant, a navigational in-

strument).

The stars and the constellations have thus, helped

in the discovery of new countries like the Americas

and Australia, which in turn facilitated coloniza-

tion by the Europeans and the subsequent spread

of their culture.

The regularity of the motions of celestial objects

enabled our ancestors to orient themselves in time

and space, satisfying their need for human order.

The ancient people learnt about the changes in the

season from repeated observation of the night sky.

Orion heralded winter, while the Summer Triangle

was the harbinger of summer or spring. The con-

stellations made it easier for the farmers to plan

ahead and form the science of agriculture.

Most ancient civilizations used astronomical calen-

dars to sow and reap their crops. Many believe that

the prehistoric megaliths of Stonehenge, the medi-

cine wheels of North America, the Aztec ‘Calendar

Stone’ and prehistoric observatories such as the

megalithic Kintraw monument in Scotland were

used for the practical applications of farming by

measuring time and seasons using the sun and

stars. Thus, astronomy went on to play a much

greater role in agriculture, engineering and archi-

tecture. Later in the course of human history,

many more archaeological sites such as Mayan

temples, Chinese tombs, Egyptian and Mexican

pyramids also illustrate the profound connection

between celestial phenomena and human beliefs.

The great pyramids of the Egyptian pharaohs were

supposed to be monuments which facilitated

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

also certain monuments erected only for astro-

nomical purposes, such as the four Jantar Mantars

in India.

The astronomical bodies also aided artists in their

flights of imagination. The effects of light at night

provided the subject for some of Dutch post-

impressionist artist Vincent Van Gogh’s most fa-

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

ry Night over the Rhone, Cafe Terrace at Night and

his magnum-opus Starry Night.

While the stars inspired Van Gogh to paint Starry

Night, his painting became the inspiration for

French composer Henri Dutilleus’s orchestral work

Timbres, Espace, Mouvement, American poet Anne

Sexton’s poem The Starry Night, Canadian compos-

er Giancarlo Scalia’s piano composition Starry

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

also known by its opening words, "Starry, Starry

Night."

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Likewise, the great unknown spawned an entire

generation of science fiction literature (The Time

Machine, The Hitchhiker’s Guide to the Galaxy,

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

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

and Arthur C. Clarke ignited the imagination of

common man to think beyond the normal. By the

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

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

crete shape to what the human mind had imag-

ined about extra-terrestrial life forms in galaxies

far, far away.

In conclusion, one can say that astronomy was the

first science, which went on to nurture several sib-

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

cultures, the first words ever spoken to a newborn

child is under the open starlit sky by the father

who lifts the baby skyward and says: “Behold at

the only thing that is and always will be superior

and greater than you.” The universe and astrono-

my is definitely superior and greater than our

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

yet ever-changing from our birth till our death.

Poets and song writers have always been intrigued

by the night sky. There are numerous songs in all

Indian languages that use the moon and the stars

as metaphors. In fact, modern day songsters re-

peatedly use the celestial bodies for appreciation

of beauty and an expression of love. But many

have also written solely about the wonder of space

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

about 10000 Light Years Away and The Carpen-

ter’s song Calling Occupants of Inter-Planetary

Craft. Pink Floyd wrote a number of space-

themed songs like Astronomi Domine and

Eclipse, and they have also been played time and

time again in outer space. Russian astronauts took

a recording of their album Delicate Sound of

Thunder, into space with them. Similarly, the late

Kalpana Chawla took Deep Purple’s Space

Truckin’ and The Aviator as her wakeup music on-

board Columbia. Likewise, the great unknown

spawned an entire generation of science fiction

literature (The Time Machine, The Hitchhiker’s

Guide to the Galaxy, Cosmos, A.I. to name a few)

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

Sagan, Issac Asimov and Arthur C. Clarke ignited

the imagination of common man to think beyond

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

popular TV series, such as Star Wars and Star

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

man mind had imagined about extra-terrestrial

life forms in galaxies far, far away.

In conclusion, one can say that astronomy was the

first science, which went on to nurture several sib-

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

cultures, the first words ever spoken to a newborn

child is under the open starlit sky by the father

who lifts the baby skyward and says: “Behold at

the only thing that is and always will be superior

and greater than you.” The universe and astrono-

my is definitely superior and greater than our

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

yet ever-changing from our birth till our death.

Photo: J. Stoop

The instruments of the Jaipur Observatory are bet-

ter maintained, and their usage for a gathering of a

database of astronomical observations to charac-

terize the instruments, is a more easily feasible

project. The basic structures of the Jantar Mantar

instruments are yet reasonably preserved. Whatev-

er 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.

The Observatories have the potential to be a live

teaching laboratory. Any modern day student of

Astronomy and Astrophysics would need to know

the basics of positional Astronomy, and would do

that learning very well, from these observatories.

The Samrat Yantra, an equinoctial sundial, was

evolved into a serious positional astronomy instru-

ment by Sawai Jai Singh, and was installed by him

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 measure-

ment is a feasibility even in its current state of dis-

repair, absence of markings and presence of so

many masonry irregularities.

This demonstration was made by a group of ob-

servers from the Nehru Planetarium, New Delhi

and amateur astronomers, working over a period of

three months, to make a temporary observational

calibration of the Samrfestival was then held on the

Winter Solstice day where time measurements ob-

tained by the visitors and school students were

compared with a clock set to 1 second accuracy

with kind help from the National Physical Labora-

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

The Misra Yantra of the Delhi Observatory is a

unique teaching instrument for positional Astrono-

my, 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 sim-

ple manner.

The other functionalities of the Misra Yantra in-

clude time measurements similar to the Samrat

Yantra, measurement of Meridian Altitudes using

the Dakshinottara Bhitti Yantra and the measure-

ment

A view of the Chakra Yantra of the Jaipur Observato-ry, with the Equinoctial sundial the Laghu Samrat

Yantra in the background.

of Ecliptic co-ordinates using

the Karka Rasi Valaya instru-

ment on the back wall of the

Misra Yantra.

There are the Ram Yantra in-

struments 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 un-

der 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

co-ordinates in many different co-ordinate systems

and are complete positional astronomy instru-

ments, in some sense. One of the Kapala Yantras at

the Jaipur observatory has also a built in capability

for theoretical conversions between different co-

ordinate systems. There is the Chakra Yantra for

measuring equatorial co-ordinates of celestial ob-

jects whose mounting is akin to a modern day

equatorially mounted telescope.

There is another aspect to be bought out, about the

observatories. We have been working with the cali-

bration of the Samrat Yantra of the Delhi observa-

tory, for its usage as an equinoctial sundial. The

amazing practical result that we found was that,

even with very temporary calibration markings

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

servatory, is capable of reading time to an accuracy

of 1 second. With more permanent calibration

markings, it should be able to better this accuracy.

This aspect needs to be studied, analyzed and em-

phasized more. The world over, 1 second accuracy

in time keeping was achieved around 1720s. At that

time, India also had an instrument that was capa-

ble of achieving 1 second or even better accuracy in

time keeping.

For 300 years this fact had not been appreciated in

practice, although theoretical statements about the

accuracy of these instruments are scattered in all

the guide books. Every day there are hundred of

visitors passing through the Observatory – not be-

ing able to appreciate this practically, even today.

For this appreciation, a complete restoration with

all markings in place is needed for the Delhi Obser-

vatory. What is also needed is a very large sized

modern day digital clock – set accurate to 1 second

precision by the National Physical Laboratories –

on display near the Observatories. This clock

should be visible from all the instruments of the

observatory, and every day’s visitor would then be

able to appreciate the accuracies of these beautiful

instruments.

Error in time obtained from using the temporarily calibrated Samrat Yantra

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. Bala-chander, Sneh Kesari, Vidushi Bhatia, Vikrant Narang, Pritpal Kaur, Arpita Pandey, Vidur Pra-kash and many other students and amateur astronomers who lent a hand. To the staff of the Jantar Mantar and the Archeological Sur-vey of India, for their support

ANGELS & DEMONS?

Yup!, that was a misleading title.

There is nothing demonic about this

picture here. But then what is this

strange halo that you see around the moon. This

winter, when you step outside the house and look

at the moon, you may yourself bear witness to

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 re-

cently.

Moon haloes are though to be caused by light pass-

ing 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.

The big question is why have sightings of moon ha-

los increased suddenly in recent times? Is it cli-

mate change? Your guess is as good as mine.

Image courtesy: Mike White, New Zealand

IN THE NEWS

AMATEUR ASTRONOMER

IMAGES EXTRASOLAR

PLANETARY DISC

Just when you thought that amateur as-

tronomy 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 Infra-

red orbiting observatory called IRAS dis-

covered 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 us-

ing image processing software he sub-

tracted 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 subtrac-

tion will not be complete.

This method is not what astronomers typi-

cally use for exoplanet detection. Typically

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!

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 )