Re: GSC 748-1618

[Patrick Wils <patrickwils@yahoo.com>]

--- Michael Koppelman <lolife@bitstream.net> wrote:
> GSC 748-1474  V=10.96  B-V=0.97 
> GSC 748-2519  V=10.51  B-V=0.96 
> GSC 748-2263  V=11.86  B-V=1.03 
>
> The program star is:
> 
> GSC 748-1618  V=11.07  B-V=0.97 

I have checked the observations of these comp stars in the online
database, and they are fairly constant (except for the "known" small
day to day variations of the Ic magnitude).  

GSC 748-1474
V = 10.88 +/- 0.02
I =  9.66 +/- 0.01

GSC 748-2519
V = 10.48 +/- 0.02
I =  9.05 +/- 0.03

GSC 748-2263
V = 12.21 +/- 0.08
I = 11.75 +/- 0.06

GSC 748-1618
V = 11.41 +/- 0.13
I = 10.65 +/- 0.07

Only GSC 748-2263 shows more scatter (probably because it is fainter). 
So the variations observed by TASS are probably genuine.
The online database has observations of a fourth night (with less
observations), showing GSC 748-1618 essentially constant ("inactive"
?)near V=11.55.
Michael, how long is your stretch of data on this star ?

Patrick


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