Re: GSC 4414-1210

["Gary W. Billings" <obs681@telusplanet.net>]

Hmmm... something funny is going on here.  My own data (the graph I put on
the wiki, and some obvervations on 7/8 July, when the star seemed to be
constant) suggested a maximum brightness of a hair brighter than V=11.5,
consistent with the TASS discovery data.  That's from images zeropoint
corrected to Tycho, which also gives a fairly good match on your sequence
stars.  I'm sorry, I *still* haven't generated a proper time series (I'm
doing a lot of development / adjustment of my reduction scripts etc and just
haven't gotten around to it).  I will continue to shoot this field when it's
convenient.

g.


----- Original Message -----
From: "Michael Koppelman" <lolife@bitstream.net>
To: "Tass" <tass@listserv.wwa.com>
Sent: Sunday, July 13, 2003 1:00 PM
Subject: Re: GSC 4414-1210


> I got a 6 hour run on this last night. Gotta like stars with high
> declinations. The results are still a bit confusing to me. See:
>
> http://www.lolife.com/astronomy/gsc4414-1210/gsc4414-1210.jpg
>
> The error bars are 0.013 and are the average error reported by Mira for
> the faintest comp star, which had an average S/N of about 86. I used
> the comp stars from Arne's sequence and unfortunately the brightest
> comp star is still 1m fainter than the program star. The above plot is
> ensemble photometry using just two comp stars, labeled 1 and 2 on the
> chart here:
>
> http://www.lolife.com/astronomy/gsc4414-1210/GSC4414_chart.pdf
>
> I tried to avoid faint companions by my choice of apertures.
>
> The 1-sigma for the comp star magnitudes is about 0.009, so the error
> bars are just about 2-sigma. The 1-sigma of the program star magnitudes
> is 0.013 with an average of 11.25. I also tried differential photometry
> against the brightest comp star with AIP4Win
> and the 1-sigma of the program star was still about 0.013.
>
> This is fairly similar to my other night of data on this and i can't
> say with certainty that this star is really variable, based on my data
> alone, although the bump near the beginning of the night looks like it
> may be statistically real. Gary Billings's data seemed much more
> conclusive. Did you ever get a chance to reduce that, Gary?
>
> Thoughts?
>
> Michael Koppelman
>
>