[Aavso-photometry] Comp star identification

arne arne at aavso.org
Wed Jun 20 19:58:56 EDT 2007


Keith Graham wrote:
> I have been submitting BVRI observatons for ASAS1282612 and BVR obsevations for KU Her. I have been using comps 119a,115a,133 and 109. Although I reduced my data using the correct magnitude for each color, I entered the chart mag for each color when submitting the data. For example, the B mag for comp 119a is 12.662. I used 12.662 for datra reduction, but I entered 11.9a in the comp column. I noticed that others submitted the actual mag for each color.  My reasoning is that it would be easier for users to ID which comp I used, but it occured to me that they might not be certain that I used the actual color mag in my reduction.
> 
> So which way is preferred?  Should I enter the chart mag or the actual color mag when submitting multi-color data? 
> 
Enter the chart mag - that is the label that we use to ensure we know
which comp star you were using.  We know what its BVRI magnitudes
are from the calibration.  The exception to this is if there is
no filter information for a given comp star.  Then give its label
in the compstar field, but place in the comments what magnitude you
assumed for that star.
Arne


More information about the Aavso-photometry mailing list