BVR transformation and instrumental magnitude

Posted by chrismlt on May 02, 2024; 8:14am
URL: http://astroimagej.170.s1.nabble.com/BVR-transformation-and-instrumental-magnitude-tp2430.html

Hello Karen,

I'm involved in the somewhat difficult process of transforming my data in the standard BVR system for reporting to the AAVSO with higher precision.
I will use some standard fields to do that, and image them - most probably the large open cluster Melotte 111, which is conveniently located in the evening sky.

https://app.aavso.org/vsd/stdfields

It is recommanded to extract the photometry of a larger number of standard stars.

I dont' think there will be a function to extract all the stars from a serie of images, so I will have to select manually a few dozen of those standard stars as comps, and maybe a fictive variable T.

Do you think this procedure is correct ?

Are the rel_flux_T1, rel_flux_C2, rel_flux_C3, and so on, correct to be used as intrumental magnitude for those standard stars ?

Any suggestion will be greatly appreciated.

Sorry to be possibly off topic,
Christophe