Yes, Raghu, of course. One is active live help, the kind that Amateur
Astronomers provide with such dedication, as in the event that you are
mentioning.

In addition, I was also thinking of providing simple horizon views in
different directions for different seasons (for a specific location,
of course) - On request, these can be provided for any location.

There is a lot of software help freely available, to befriend the
skies, Atul. Try the simplest ones to begin with, like skyglobe. Just
type "skyglobe" and "download" in google, that would help find it.

I am also thinking that horizon views - the sky looking at North,
South, East and West or other combinations (at specific times)- would
be an added help, to begin with. It is these horizon views (for
different times, for Delhi) and putting them together on the website,
that will take me some time. If anyone else would also do that on
their websites (for different locations) and post with the link here,
it would be very useful.

Rathnasree

PS: is anyone getting bothered by receiving too many e-mails from the
group? There is the possibility of opting for daily digests or the
option of receiving no e-mail, but, participating from the group
website. Members can set these options on their own, at the group
website, or can let me know, if they would like their e-mail id to be
set for a daily digest or a no e-mail mode.

--- In Astronomy_Activities_2009@yahoogroups.com, RAGHU KALRA
<kalraraghu@...> wrote:
>
> mam i think AAAD will be doing something on International Sidewalk
Astronomy Day Night and Yuri’s night (both on 12th April 2008
Saturday)   may be something in the planetarium itself most probably
it it will be an evening observation
> raghu kalra
>

Hello

First of all, let me begin by introducing myself. I am a physics
student, having done my graduation from St. Stephen's at DU and am in
Cambridge at the moment, pursuing my masters in physics. I've been an
amateur astronomer for a while now.

With regard to the question on selective absorption by the atmosphere,
there is something that I'd like to point out - most of the absorption
occurs due to the excitations of molecules as a whole, and not atomic
ones. The reason is that atomic excitations require a lot of energy (~
few electron volts) and writing E = h*f, where h is Planck's constant
and f is the frequency of the radiation absorbed, we find that the
radiation absorbed mostly corresponds to the Ultraviolet and X-rays.

Large sections of the spectrum are absorbed rather by molecules like
water vapour present in the atmosphere. Infrared radiation causes
vibrational excitations and microwave radiation (wavelength ~
millimeters) causes rotational excitations of water vapour,
Carbon-di-oxide, ozone and other molecules present in the atmosphere.

If you go to the first reference link below, there is a graph showing
the wavelengths that are absorbed by the Earth's atmosphere. The blue
bands correspond to absorption. The region from 1 Angstrom to 1000
Angstrom corresponds to absorption by atoms, often getting ionised in
the process. This is followed by the window of visible and near UV,
where there is no absorptoin. The bands from 1000 Angstrom through to
infrared region are vibrational molecular excitations, followed by
rotational ones. This band has deep windows where no molecules absorb,
which allows ground-based infrared telescopes to function.

This is followed by the Radio window from hundreds of Gigahertz
(centimeter wavelengths) to about 10 MHz (wavelengths ~ tens of
meters). The atmosphere is transparent in this region, allowing radio
waves from distant galaxies to reach us. This is where Radio
telescopes like the GMRT operate. With longer wavelengths, the
ionosphere kicks in. The ionosphere is a region of ionised gas
starting about 85 km above the earth's surface, that absorbs strongly
any radiation passing through it below the plasma frequency, which is
a characteristic frequency depending upon the density of free
electrons. This varies with time of day and year. This is also the
atmospheric layer responsible for long distance high-frequency (HF)
radio propagation.

If one wishes to observe in any region of the spectrum which the
atmosphere does not allow through, the only way to do so is to place
observatories either on mountain tops (Mt. Palomar, Mt. Wilson, Kitt
Peak, Mauna Kea) or in sapce (Spitzer Space Telescope (infrared),
Chandra X-ray observatory, XMM-Newton X-ray observatory, Compton Gamma
ray observatory).

Tanmoy

References:
http://www.everythingweather.com/atmospheric-radiation/absorption.shtml
http://en.wikipedia.org/wiki/Ionosphere
http://en.wikipedia.org/wiki/Space_observatory

For what is meant by "molecular vibrational excitations":
http://en.wikipedia.org/wiki/Water_absorption
For what is meant by "molecular rotational excitations":
http://en.wikipedia.org/wiki/Rotational_spectroscopy
(Anyone has a simpler article on this?)

Atul, I am sure, there will be many resources made available, on
different websites of the members. Give me a week's time, I am
planning on something very specific related to giving very simple help
for naked eye sky gazing as well as a thumb rule help for quantifying
light pollution from different locations.

I say a week - maybe - it could be a little more than a week before I
could put that up :-)

Just at the moment, I am still struggling to put up some simple
eclipse information on our website, following a question in the group
- things may be slow, but, I am sure there will be a lot of useful
resources put up by various members soon.

Rathnasree

--- In Astronomy_Activities_2009@yahoogroups.com, Atul Asthana
<atulasthana@...> wrote:
>
> Are there any resources (tutorials) for naked eye astronomy?
>
>

Thank you so much, Prof. Govind Swaroop. It would be wonderful to have
an ISRO presence in the group. I myself have literally hundreds of
questions about Chandrayaan that I would like to ask.

I did utilise all oppurtunity of asking Prof. Annadurai, at the Nashik
meeting of Planetaria, that very kindly made such an interaction
possible. I now have many more questions and hopes of students from
here, working on some projects related with the Chandrayaan data.

Rathnasree, Nehru Planetarium, New Delhi

--- In Astronomy_Activities_2009@yahoogroups.com, "Govind Swarup"
<gswarup29@...> wrote:
>
> To Dr Jayati Datta, Program Director, ISRO, Bangalore
> Dear Dr Jayati
> Dr Ratnasree and others of the various planetariumss in India have
formed a
> yahoo group for the students to ask Qs. re astronomy and related
subjects.
> It is a wonderful initiative, only 2 weeks old or so, and has
created lot of
> enthusism. The initial idea is to serve a platform for the International
> Year of Astronomy 2009.
> It would be nice if you could get some scientists from ISRO to join
> particularly to answer Qs. re Space exploration, space astronomy etc.
>
> It was great meeting Dr Madhavan Nair, Prof. U R Rao, you and many
others at
> Ooty during the Space Science Symposium held at the ooty Radio Telescope
> from Feb 25-29 2008. Thanks very much for your team and to Prof.
Manoharan
> to make it highly successful.
>
> With best regards
>
> Govind Swarup
>

                                               INDIAN PHYSICS ASSOCIATION

PRIP Shed, Room No.4,

Bhabha Atomic Research Centre,

Trombay, Mumbai –400085, INDIA

Telephone: +91 22 2559 5369

14 March 2008

INVITATION

M.M. Chugani Memorial Award -2006

M. M. Chugani Memorial Award of the Indian Physics Association for the year 2006 has been given to G Madhavan Nair, Chairman, Indian Space Research Organisation, Secretary, Department of Space, Government of India

The Chugani award is given for excellence in applied physics and carries a citation, gold medal and cash of Rs. one lakh.

Prof. Ashok Misra, Director, Indian Institute of Technology Bombay, Mumbai will present award on 18 March 2008 at 4 p.m.at the P. C. Saxena Auditorium, I. I.T. Bombay, Powai, Mumbai - 400076

You all are cordially invited. 

Suhas B. Naik-Satam

Convenor-Media Relations

Indian Physics Association.

Tel.No24920510 (O), 25226410(R)

Fax. No. 24973827 Mobile: 9820000726

Are there any resources (tutorials) for naked eye astronomy?



--------Please help find cure for diseases----------
Your participation can help lead to a cure for diseases like Cancer,
Alzheimer's Disease,  Huntington's Disease, Osteogenesis Imperfecta,
Parkinson's Disease etc. You can donate some of your computing power to solve
mathematical problems related to protein folding. Read more at
http://folding.stanford.edu/

Thank you, Jyoti.

Your school students had participated with so much enthusiasm in the
Solar System Marathon that was conducted by our amateur astronomers.

Just at the moment, the greatest help that you could provide would be
to spread the word to your students and ask all those interested, to
join the group. If you like, you can just send to me the list of
e-mail addresses of interested students and I will add them to the group.

And, yes, I am sure that there would be many collaborative projects
with your school, related to IYA 2009, that could be discussed here
and that could materialise.

Rathnasree, Nehru Planetarium, New Delhi

--- In Astronomy_Activities_2009@yahoogroups.com, "Jyoti" <jarora@...>
wrote:
>
> Resp Ms Ratnashree
>
>
>
> We at Amity International School would like to participate actively
in the
> International Year of Astronomy 2009. We would be happy to host any
event /
> seminar/workshop/prog or contribute in any way you find appropriate.
>
> If need be I can come over to meet you.( I have been wanting to meet
me in
> person & personally congratulate you for all the fantastic work
going on in
> the planetarium for the children!)
>
>
>
> All the best for the Programme!
>
>
>
> Thanks & Regards
>
>
>
> Jyoti Arora
>
> Coordinator
>
> VIDYUTTAM
>
> Amity Educational Resource Centre
>
> AMITY INTERNATIONAL SCHOOLS
>
> E-27 Defence Colony, New Delhi-110024
>
> Tel: +91 (11) 41888315
>
> Mobile: +91 9810347744
>
> website: www.amity.edu
>
>
>

Thank you, please do help us by spreading the word around - as many
students and astronomy enthusiasts as possible - and the group will, I
hope, be a place where there could be a very fruitful co-existence of
questions asked without any hesitation by just about anyone, along
with expert discussions.

Rathnasree

--- In Astronomy_Activities_2009@yahoogroups.com, "srijays"
<srijays@...> wrote:
>
> Hi Ratnasree,this is a brilliant initiative in popularizing astronomy
> and Astrophysics.
>

--- In Astronomy_Activities_2009@yahoogroups.com, "larry"
<hilltopobservatory@...> wrote:
>
> Hello I guess I should introduce myself to the group. I am 53 years
> old, and have been observing the night sky for 35 years. I have a
> private observatory in southwest Texas, and have been rewarded with
> exceptional skies for viewing. I have written a book on astronomy, and
> would be glad to share what I know with the group.
>
> Respectively Yours
>
> Larry Stringer
>

Welcome to the group, Larry, it is wonderful to have members from such
widely separated geographical locations and with such expertise, in
the group.

The student membership (though steadily increasing) is yet to grow -
any help that can be given to make this grow, would be great!

Rathnasree, Nehru Planetarium, New Delhi

Hello I guess I should introduce myself to the group. I am 53 years
old, and have been observing the night sky for 35 years. I have a
private observatory in southwest Texas, and have been rewarded with
exceptional skies for viewing. I have written a book on astronomy, and
would be glad to share what I know with the group.

Respectively Yours

Larry Stringer

--- In
Astronomy_Activities_2009@yahoogroups.com, "nandivada_rathnasree"
<rathnasree@...> wrote:
>
> --- In Astronomy_Activities_2009@yahoogroups.com, "larry"
> <hilltopobservatory@> wrote:
>
> > As I have stated before I am willing (with pleasure I might add)
to
> > discuss any astronomy topic that you may desire. All you have to
do
> > is ask.
> >
> > Larry
> >
>
> We may be a little slow going as we are not using very active
> advertising of the group - only through students who visit the
> Planetarium.
>
> However, there are a few questions that have been asked by the
> students - off group or during their visit at the Planetarium and
> questions that have not been discussed fully.
>
> One question asked by some students had been to do with the reason
why
> most of the radiation other than Optical and Radio, is absorbed by
the
> atmosphere - why there are those specific absorptions are scattering
> that are responsible for this. I think that the students (DIET
> students?) who asked this question are in the group.
>
> If this could be discussed in some amount of detail, it would be
very
> interesting. I do mean to learn a little more about this and post
with
> whatever I have learnt, but, I might not be able to do that until
the
> day after tomorrow.
>
> Meanwhile, I will definitely put up the eclipse information that I
> promised Richa, on our website.
>
> Rathnasree, Nehru Planetarium, New Delhi
>
Atmospheric Absorption of Radiation by our Atmosphere

  Most of the gases that make up our atmosphere are referred to
as "selective absorbers". What I mean by that is, each gas absorbs
only certain wavelengths of light. The reason for this of course is
that the electrons that orbit the nucleus of an atom have what we
call fixed orbital shells. The orbital shell for each atom is
different. For example an atom like hydrogen, its electrons, orbit at
set distances and are different than those for atoms of say
nitrogen.

  Each orbital shell is associated with a given energy level; the
greater the distance from the nucleus of the atom, the greater the
energy level. In observing atoms, you will find that electrons will
jump to a higher shell when excited by the absorption of energy. The
photon must have the exact amount of energy to move the electron
from, say, shell one to shell two. If the incoming light (photons)
doesn't have enough energy to move the electron to shell two, then no
action will take place so the atom will not stay in this excited,
state for any length of time. When the potential energy is emitted,
and the electron returns to a stable state or its "ground state" (as
some people call it) which is the lowest energy level or orbital
distance that it can achieve. If you recall your physics class you
will remember that the amount of energy carried by a photon depends
on the carrier wavelength. Thus the atoms that comprise a gas can
only absorb, or emit, particular wavelengths of energy.

  So to make a long story short, when you look at the results of
selective absorption, you will find that there is very little
absorption for the atmosphere as a whole in the shortwave end of the
light spectrum, especially in the visible light band, which is the
band of maximum emission for the Sun. So in a nut shell, the
atmosphere absorbs far more emmissions in the longwave band of the
electromagnetic spectrum which is the region of maximum emission
(10µm) for the Earth. Well I hope that I have not bored you guy's to
death, and I hope that maybe I have cleared some things up for you.

Peace To All

Larry




----------------------------------------------------------------------
----------

Hi Ratnasree,this is a brilliant initiative in popularizing astronomy
and Astrophysics.

Vikram, nice to see you in the group and please do help us get some
BITS Pilani students in the group.

Vidhu, likewise, it would be wonderful if Sardar Patel Vidyalaya
students could be enticed to join the group.

And so on, to all the teachers in the group.

I have prepared several single page word documents, which advertise
the group and give information regarding joining the group. I will
upload them to the files section of the group tomorrow and if anyone
would download them and put them up in their
schools/colleges/Institutions it would help so much.

Alternately, anyone could make a poster of their own  - the poster I
have made only states the name of the group and the method of joining
the group - no other affiliation, as this is going to be so much of a
joint effort - we are going to take help from just about every
enthusiast - from anywhere in the world :-)

Rathnasree, Nehru Planetarium, New Delhi

Vikram, nice to see you in the group and please do help us get some
BITS Pilani students in the group.

Vidhu, likewise, it would be wonderful if Sardar Patel Vidyalaya
students could be enticed to join the group.

And so on, to all the teachers in the group.

I have prepared several single page word documents, which advertise
the group and give information regarding joining the group. I will
upload them to the files section of the group tomorrow and if anyone
would download them and put them up in their
schools/colleges/Institutions it would help so much.

Alternately, anyone could make a poster of their own  - the poster I
have made only states the name of the group and the method of joining
the group - no other affiliation, as this is going to be so much of a
joint effort - we are going to take help from just about every
enthusiast - from anywhere in the world :-)

Rathnasree, Nehru Planetarium, New Delhi

--- In Astronomy_Activities_2009@yahoogroups.com, "larry"
<hilltopobservatory@...> wrote:

> As I have stated before I am willing (with pleasure I might add) to
> discuss any astronomy topic that you may desire. All you have to do
> is ask.
>
> Larry
>

We may be a little slow going as we are not using very active
advertising of the group - only through students who visit the
Planetarium.

However, there are a few questions that have been asked by the
students - off group or during their visit at the Planetarium and
questions that have not been discussed fully.

One question asked by some students had been to do with the reason why
most of the radiation other than Optical and Radio, is absorbed by the
atmosphere - why there are those specific absorptions are scattering
that are responsible for this. I think that the students (DIET
students?) who asked this question are in the group.

If this could be discussed in some amount of detail, it would be very
interesting. I do mean to learn a little more about this and post with
whatever I have learnt, but, I might not be able to do that until the
day after tomorrow.

Meanwhile, I will definitely put up the eclipse information that I
promised Richa, on our website.

Rathnasree, Nehru Planetarium, New Delhi

--- In
Astronomy_Activities_2009@yahoogroups.com, "nandivada_rathnasree"
<rathnasree@...> wrote:
>
>
> We have crossed the half century mark in membership,although the
> student membership is yet to grow. We have less of students and more
> of educators in the group as yet. Please do spread the word around
> about the group (although activity has not yet picked up in the
group,
> I am confident it will, in a few week's time).
>
> The spirit of the group is to function as a "Ask an
> Astronomer/Educator" chat room.
>
> For the students in the group, I wanted to mention that please do
not
> feel hesitant to post anything that comes to your mind, related to
> astronomy - whatever questions that you have. It may take some time
> for questions to be discussed as everyone would be having busy
> schedules, but, there are sure to be discussions related to your
> questions sometime or other. If a question has been ignored for some
> time due to everyone being busy just at that time, repeat it after a
> few days.
>
> Richa, you mentioned that you wanted to know more about solar
> eclipses.   If you would like to, please do post again being a
little
> more specific about which aspect of a solar eclipse you would like
to
> have clarificaions about. Please do not hesitate to ask whatever
comes
> to your mind.
>
> I will also be posting a little later about a simple method with
which
> one might be able to estimate relative angular diameters of the Sun
> and the Moon, when we are witnessing the partial phases of a solar
> eclipse. We did this measurement with two solar eclipses - one a
total
> one and another an annular one (I will discuss these two kinds of
> eclipses in another mail, if you want clarification about these two
> kinds) - both these eclipses were seen partial at Delhi and with our
> simple method we could measure the relative angular diameter of the
> Sun and the Moon and infer why one eclipse was total while one was
> annular.
>
> Richa, would you like me to elaborate on this measurement and the
two
> kinds of solar eclipses?
>
> Rathnasree, Nehru Planetarium, New Delhi.
>

As I have stated before I am willing (with pleasure I might add) to
discuss any astronomy topic that you may desire. All you have to do
is ask.

Larry

We have crossed the half century mark in membership,although the
student membership is yet to grow. We have less of students and more
of educators in the group as yet. Please do spread the word around
about the group (although activity has not yet picked up in the group,
I am confident it will, in a few week's time).

The spirit of the group is to function as a "Ask an
Astronomer/Educator" chat room.

For the students in the group, I wanted to mention that please do not
feel hesitant to post anything that comes to your mind, related to
astronomy - whatever questions that you have. It may take some time
for questions to be discussed as everyone would be having busy
schedules, but, there are sure to be discussions related to your
questions sometime or other. If a question has been ignored for some
time due to everyone being busy just at that time, repeat it after a
few days.

Richa, you mentioned that you wanted to know more about solar
eclipses.   If you would like to, please do post again being a little
more specific about which aspect of a solar eclipse you would like to
have clarificaions about. Please do not hesitate to ask whatever comes
to your mind.

I will also be posting a little later about a simple method with which
one might be able to estimate relative angular diameters of the Sun
and the Moon, when we are witnessing the partial phases of a solar
eclipse. We did this measurement with two solar eclipses - one a total
one and another an annular one (I will discuss these two kinds of
eclipses in another mail, if you want clarification about these two
kinds) - both these eclipses were seen partial at Delhi and with our
simple method we could measure the relative angular diameter of the
Sun and the Moon and infer why one eclipse was total while one was
annular.

Richa, would you like me to elaborate on this measurement and the two
kinds of solar eclipses?

Rathnasree, Nehru Planetarium, New Delhi.

Hello Vidur,

That's a very useful preview that you have put at the AAAD site. We
should probably have a small segment somewhere that would help
visitors understand the terms in the PDF files (all those contacts!),
with figures. Of course, these are explained at the Espenak NASA site,
but, no harm in putting it down in our own bohemianz way :-)

Rathnasree

--- In Astronomy_Activities_2009@yahoogroups.com, "Vidur"
<vidur_itm@...> wrote:
>
> I've put up a preview page.....there's no way I'm missing this next year
>
> http://aaadelhi.org/?q=node/48
>

Hello Vidur,

That's a very useful preview that you have put at the AAAD site. We
should probably have a small segment somewhere that would help
visitors understand the terms in the PDF files (all those contacts!),
with figures. Of course, these are explained at the Espenak NASA site,
but, no harm in putting it down in our own bohemianz way :-)

Rathnasree

--- In Astronomy_Activities_2009@yahoogroups.com, "Vidur"
<vidur_itm@...> wrote:
>
> I've put up a preview page.....there's no way I'm missing this next year
>
> http://aaadelhi.org/?q=node/48
>

I've put up a preview page.....there's no way I'm missing this next year

http://aaadelhi.org/?q=node/48

--- In Astronomy_Activities_2009@yahoogroups.com, "RICHA"
<richa_gupta449@...> wrote:
>
> hello
>
> I want to know more about the solar esclipse.
>

Richa, could you be a little more specific as to what aspect of a
solar eclipse you would like information about?

There is a solar eclipse coming up in August 2008 and then the Total
SOlar eclipse visible from India, in 2009 (not total in Delhi). We
should make all possible preparations for it.

Do you wish to know about the conditions for the occurence of a solar
eclipse?

A solar eclipse happens when the Moon comes exactly in between the Sun
and the Earth. By a funny coincidence, the Moon, which is about 400
times smaller than the Sun, is also about 400 times closer to us than
the Sun. This is the reason why, the angular diameter of the Sun and
the Moon are about the same (not always though, as there are
elliptical orbits involved and we do have annular solar eclipses
related to this - may be we could discuss this more in detail, if
there are questions).

One might think that the New Moon is the position when the Moon would
come exactly in between the Earth and the Sun - it does do that
sometimes and we do have solar eclipses. But, not every New Moon
results in a solar eclipse as the orbit of the Earth around the Sun
and the orbit of the Moon around the Earth are not in one plane -
there is a small angle of about 5 degrees between them. During a New
Moon, while the general position of the Moon is in between the Earth
and the Sun, it might be just a little above or below the line joining
the Earth and the Sun.

Richa, we could discuss this in detail or you may be knwoing these
aspects already.

That is why, you would need to be a little specific in terms of which
aspect of a solar eclipse you would like the discussion to be about.

I will wait for more clarification on your question.

Rathnasree

PS: Avantika, I have added the e-mail id of your friend, to the group.
Please let me know the e-mail addresses of others who might be
interested in joining the group.

Ma'am,
I have invited my friend Shashank Shekhar
(shashankshekhar333@...) to join this group.
Avantika

hello

I want to know more about the solar esclipse.

The group is yet to grow and become active, perhaps in a week or so. I
am going to be away until Monday. Meanwhile, in case we get any
spamming members or other usual group problems - Rohan and Som, I have
made both of you moderators, please do take care of such problems if
they crop up in my absence.

The DIET students who had attended a workshop at the Plani had a lot
of questions - you can post them to the group - just send your mail to
Astronomy_Activities_2009@yahoogroups.com  Answers may take some time
to come in, as the group is yet to grow.

There were some questions about the reason why we receive only the
Optical and the Radio window of radiations from the Sun and other
bodies in space, at the Earth.

The Ultraviolet end of the radiation is absorbed by the Ozone layer
high in the atmosphere (in the stratosphere), the  infrared segment by
water molecules lower down in the atmosphere. These absorptions are to
do with the type of interactions with the absorbing/scattering
particles and the wavelengths of the absorbed radiation. I would like
very much to learn more about this, and perhaps some discussion would
help clarify things.

I will pick this topic up after I return, meanwhile, I hope others
will pitch in and help the discussions along.

Those members who are new to the yahoogroup environment, you can also
post to the group, by just replying to the group messages.

Hello everyone, I have just started the process of adding members to
the group and initiating discussions. This group is for co-ordinating
Astronomy related actvities, building up to the year 2009 - the
International Year of Astronomy.

The members being added are those who have interacted with us at the
Planetarium, in Delhi, and have expressed an interest in being part of
such a group.

If anyone knows that their friends would be interested in being a
member of the group, they can post the e-mail ids of the people
interested, in the group, I will add them to the group. I can add only
10 members in a day. People can become members of the group also by
going to the site

http://groups.yahoo.com/groups/Astronomy_Activities_2009

Please spread the word around, and meanwhile have patience. The group
might take a little time to build up and be useful for discussions.

Rathnasree, Nehru Planetarium, New Delhi.