[vsnet-survey 26] (fwd) Re: IDs for STARE variables

[Taichi Kato <tkato>]

From: "Tim Brown" <timbrown@hao.ucar.edu>
Date: Mon, 22 May 2000 09:46:05 -0600
To: Brian Skiff <bas@lowell.edu>, boetiker@safety.lowell.edu,
        dubois@simbad.u-strasbg.fr, dunham@safety.lowell.edu,
        francois@simbad.u-strasbg.fr, gerard@simbad.u-strasbg.fr,
        timbrown@hao.UCAR.EDU, vsnet-id@kusastro.kyoto-u.ac.jp,
        vsnet-survey@kusastro.kyoto-u.ac.jp
Subject: [vsnet-id 0] Re: IDs for STARE variables

Hello All --

Thanks, Brian, for the info about the STARE variables.  I had not known
you were working on them, but I'm glad you did.  One comment about the
colors, mostly to reinforce your observation that they should not be
trusted:  The colors in that list are indeed on a strange instrumental
scale that only vaguely resembles Johnson BVR.  Moreover, especially
for our older data (which these are), they are afflicted with enormous
random errors (0.2 mag rms!).  The original intent was to measure something
at least statistically connected with the idea of color, so as to have
a basis for estimating color-dependent extinction terms in the ensemble
calibration.  As it turned out, that is what we succeeded in doing, but
not much more than that.  I have put a little effort into improving the
color estimates since then, and made some improvements, but the absolute
photometry is still nothing to brag about.  The B-V colors, in particular,
are prone to problems because of the low blue sensitivity of our frontside-
illuminated CCD.  We should probably put some disclaimer to this effect
on the web site.

Cheers -- Tim Brown

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