[Aavso-photometry] RR Boo I band observation

[Maurizio Martinengo]

Thanks, now it is clear.
Infact in the old-style 05/93 CCD chart the 000-BBV-686 has a reported I mag
of 12.625 instead of the SDSS value of 10.295.
I'll upload again using 05/03 sequence as the 000-BBV-693 is unfortunately
just out my FOV.

Maurizio

2008/7/6 Arne Henden <arne at aavso.org>:

> 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
>