[Aavso-photometry] RR Boo I band observation

[Arne Henden]

On Sun, Jul 6, 2008 at 12:54 PM, Maurizio Martinengo
<maurizio.martinengo at gmail.com> wrote:
> I'm new to multi-band photometry and Mira targets, so I need some help.
> Last friday evening I imaged RR Boo in BVRI finding magnitudes (especially
> in I band) that doesn't fit well the light curve behaviour for this star.
> After double check the results I uploaded the datas (ca. 6.5 I Mag - MMG).
> I'll appreciate confirmations from other observers or any suggestions for
> possible errors involved in my measures.
>
Yup, it looks like you are about 2.5 magnitudes too bright.  I think the
problem is the comparison stars.  Both 000-BBV-686 and 000-BBB-692
have Ic from SDSS, and this is an error - both stars are very saturated in
that survey.  Usually (B-V) ~ (V-I), and if you look at the (B-V) values for
these two stars, it is obvious that they are displayed about 2.5 magnitudes
too bright at Ic.  I think that 000-BBV-693 is closer to correct, and you
might try your reductions just using that star as a comp rather than using
an ensemble solution, and see what you get.  I've put this problem on
my list of things to correct in the next release.
Arne