[Aavso-photometry] photometry of 27 virginis-thanks

[trupti ranka]

hello everyone,
  thank you very much for all your replies. I can't take anymore observations as it has already started raining in India and skies wont clear up untill november :-( . i used integration time of 1 second for my observations and did take 2sets of reading each contiaining 4 reading i.e total eight reading per set.(approx eight secs for each set). this same procedure i applied even for comparison stars and did it almost continuously for whole night.
  i will check the softwares shortly(once i finish with my exams!!) and let you all know if i get a good output.
  thanks a lot again for all your recommendations,
  regards
  Trupti 

    



From: "trupti ranka" 
To: 
Sent: Thursday, May 31, 2007 11:04 PM
Subject: [Aavso-photometry] photometry of 27 virginis


> hello everybody,
> A month ago I started with photometry of a variable star named
> 27 virginis. i was using a 14" celestron telescope and SSP3-A
> photometer. Sky map pro software said that the star magnitude
> varies from 6.19 to 6.33 which we thought was good enough to
> be observed by 14" telescope. but after initial data reduction we
> found that star magnitude varies only by 0.05 magnitude. we
> checked some IBVS papers which confirmed are data. The
> papers (1975,1977,1980)reported a magnitude differences of
> about 0.02 to 0.03.
> Now the problem is that since we were using a 14" telescope
> for such a small amplitide variation the data accuracy is poor.
> also the star is multi periodic delta scuti star. Its period varies
> fro 0.5 hrs to 3 Hrs (according to IBVS papers). I would like to
> know if there is a better and more relaible way to calculate error
> other that 1/SNR or some special data reductoin tricks to improve
> accuracy. also i would like to know if there is a specific software
> for calcualting periods of short duration multi periodic stars(i
> heard there is a FORTRAN based software but can't find it) .
> this has turned into a tricky star for data reduction but i would
> like have some help as i have spend lots of nights observing
> it and don't want the data to go waste.
>
> looking foward for you replies,
> regards,
> Trupti



 
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