Hello Dear Shireen, wish you good luck for Physics with Maths and for astronomy
for further learnings.

Welcome to write me and pleased to know your interests in astronomy and physics
and maths too , but I surprised to know that you did not put your question to
the astronomy groups? some one must be doing that work - if not by them selves
must be using some internet use. did any one in group put the data on the group
message or did any one presented the method of calculation and actual results of
their calculations with their answers of figures? is any one does not know what
to do with the results they will be using the ready made forms available from
the internet source.

any way hope your maths is good and for a trigonometric calculation we need to
tale at least on base - knows either distance of the moon (which is changing
every time from mini to maxi) OR the diameter of the Moon/Earths diameter (ready
made or derived by actual reading of experimental results) when the sun is on
over head @ Local time on that longitude and latitudes. (eg On 21 June - on
23.5N at the local time of the Longitude and not the IST)

I have seen your results and realised your mistake as reading from 2-1 is not
near the reading 4-3 - so you have made mistakes in reading 3/4 as you say no 3.
similarly 3-1 is not near to 4-2 but still we may use 4-2 as reliable reading.
to measure angle of the moon in the sky. eg say 0.53 degree approximate. and if
you know the distance of moon at that time you can find the Diameter of the MOON
or visa versa.

Also we need to take multiple readings for different places of the Earth as we
use that distance on the Earth as a triangle base to measure the angle with the
moon. or one can use their own reading for just to know the facts. but accuracy
is better with multiple source of readings or multiple readings at the place.

You also did not sent me any photographs to see if what was the angle of
entrance and exit behind moon disk. that may not be necessary from the middle of
the sun but different place on earth has different angles . so better the
results are taken from similar Latitude to compare.

From your results you can use one only and draw a circle of say 20cm diameter
and also use your photograph picture to adjust to 20 Cm diameter and print that
out for all contacts. and draw a line for points 1/2 - S to 3/4 F- measure that
length and time taken by moon to travel that distance. S to F SF.

Diameter you adjusted was 20 cm so compare the ration 20/SF. multiply by the
time for distance SF that will give you a time of the moon to move in space
equal to distance of diameter of the MOON.

SO what's the speed of the moon in the space (is changing from max to Min
according from the distance from the Earth and calculations) or use ready made
data sours as every one does as no one knows how to do that.

sample example - say moon distance is D and diameter is R so Moon travels 360
degrees around the Earth in about 28.5 days is about 2 pai R = 2x3.14x300000 km
approx = 1884956 km in 28.5 days x24 hours x 3600 Sec = 2462400 sec so 1884956
Mk / 2462400 s =speed of moon is 0.765495 km /s.

you calculate on your readings and compare from this - how long it took the time
in sec for 3-1/ or 4-2 and at that above speed the distance travelled by moon
at that SF and what was the ratio of MOON diameter and SF and hope fully one can
calculate the approximate diameter of MOON at Moon Equator GOOD LUCK

from yours Dr.BHUDIA-Science Group Of INDIA.
http://uk.groups.yahoo.com/group/venustransit_2004/
President:"Kutch Science Foundation".
Founder :"Kutch Amateurs Astronomers Club - Bhuj - Kutch".
Life Member:"kutch Itihaas Parishad".
kutchscience@..., kutchscience@...,
http://uk.geocities.com/wildlifeofkutch/ http://www.geocities.com/kutchscience
http://profiles.yahoo.com/kutchscience2000
http://in.groups.yahoo.com/group/scienceclubofindia
http://in.groups.yahoo.com/group/kutchscience
http://in.groups.yahoo.com/group/kachchh
http://in.groups.yahoo.com/group/bhuj
Do visit our ABOVE Clubs/Groups of Science club of India, Science
Group of India.

From: SHIREEN GANGAL
Sent: Sunday, April 16, 2006 7:19 PM
Subject: need your guidance sir...


Dear Sir

Well let me first introduce myself. I am Shireen Gangal. I live in Rasayani.its
about 55km from Mumbai. I am greatly interested in Astronomy. Also I am from the
same group as you are i.e. "astronomyclubindai." I have read few of your mails
to the group so thought to write to you.

To tell you more about me I have just given my 12th science exam. I am greatly
interested in physics and astrophysics and have decided to opt for career in
physics: may be B.Sc and further! I have a 5" reflector telescope taken from
Techno Vision System. I also have just bought digcam. Also I regularly visit
Vangani sky observation programs arranged by Khagol Mandal [if you know]
Regarding astro I had given only Olympiad last year and cleared first level but
could not go further for camp due lack of guidance. That's all about my
Astronomy!! Just a basic huge interest!!!

As you know there was occultation of Spica on 13th. I had synchronized my clock
with Abhay Deshpande Sir [u must be knowing him] I have taken the timings but I
don't know what to do further. I mean what's the use of occultation? I have
heard of some calculations to be done further for finding earth-moon distance
and moon diameter etc. I am eager to calculate something on the basis of my
timings!! Can you please guide me for the same?

These are my exact occultation timings:
First contact: 09:10:33 pm
Second contact: 09:11:04 pm
Third contact: 09:49:22pm
Fourth contact: 09:50:48 pm
To be frank I was not able to properly see the third contact and so not sure
about exact timing. It was the first time I observed the occultation so I was
searching for the star before third contact! Rest all timings are exact as per
my obs. I also took photos as Hrishikesh Joglekar sir told me that though star
is not visible in photo still for moon's alignment they are necessary. Then what
to do with those photos?

I would be highly obliged if you spare some time and guide me in solving my
"SMALL DOUBT"

Thank you,
Shireen.


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