[Aavso-photometry] Time series for GK Persei

[Jeff Hopkins]

Hi Gianiuca,

I am not familiar with GK Persei, but you have a 0.08 magnitude 
variation in less than 2 minutes, which is big and fast.  That would 
be suspect.

What I would do is make sure I was doing differential filter 
photometry, take 3-20 second exposures and repeat every 10 minutes 
for several tries. Then average each set of 3 and take a standard 
deviation. Then look at all the sets and see if you see any 
significant changes.

The changes you see may be real, but without a more rigorous 
approach, I would not trust them.

Good luck.

Jeff

At 12:05 -0700 03/22/2008, gianlucaros at gmail.com wrote:
>I have experimented to take TS of GK Persei on Feb 24th to see if I
>can detect the small fluctuations around minimum. I have actually
>taken 5 consecutive exposures 20 sec each and done the calibration
>with both darks and flats. Since I get 5 different mag value (13.19,
>13.23, 13.13.27,13.22,13.23) I wonder whether such measurements are
>indication of the behaviour of the star rather than problems in
>accuracy. Sorry for asking a question that could be trivial to answer.
>Gianluca (RGN)

-- 
Jeff Hopkins
HPO SOFT
Counting Photons
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