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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 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."
It’s
no
t V
an
Go
gh
’s S
tarr
y n
igh
ts,
bu
t th
is t
rib
ute
to
th
e m
ast
erp
iece
by
Rip
Cro
nk
is
an
ce
ntr
al
ico
n i
n V
en
ice
’s s
tre
ets
cap
e.
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 )