[vsnet-chat 5380] Re: V4641 Sgr: observations from last night

[Gianluca Masi <gianmasi@fr.flashnet.it>]

Dear Arne,
thank you for your comments on the posted light curve. Unfortunately, I cannot
check now the sequence, but I will do next monday. Anyway, I've posted on the
web an image showing V, C1 and C2. As for C1, it looks a bit elongated, maybe
for a close "companion". I measured the star as a whole. As for C2, it is
well-located in the field, but its variability cannot be excluded.

The field is at

http://vsnet.bellatrixobservatory.org/v4641sgrcomp.gif

Please note this is not an image from the run, as it was grabbed with a smaller
telescope.

The reason why I did the explicit plots for both V-C1 and V-C2 was to document
any strange behaviour due to the differential atmospheric effects, because of
the limited altitude of the target.

I can reduce the data using different stars, to see how they will work.

Regards,
Gianluca


Scrive aah@nofs.navy.mil:

> At first glance, it looks like Gianluca's C2 is slightly 

variable.
> Could you find the star in
> 

http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/v4641sgr.d

at
> and let us know what the UBVRI magnitudes/colors are?  

Just as
> a reminder to all observers, Bruce Sumner has created a 

photometric
> sequence for this field, also found at
> 

http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/sumner/v46

41sgr.dat
> You will need to worry about blending/neighbors in this 

crowded field
> if you want to do high-quality photometry.
> Arne
> 

-- 
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* Gianluca Masi                           "Two things fill the soul   *
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* web:  http://vsnet.bellatrixobservatory.org             I. Kant       *
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