[Aavso-photometry] photometry of 27 virginis

[trupti ranka]

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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