I’m an astrophysicist who is also interested in astrophotography. My research field is completely different but I’ve been a huge fan of AAVSO for a long time. I would like to start contributing as I have a setup at an observatory under Bortle 1 skies (RedCat 51, ASI2600MM) and image 200+ days per year. I currently have Antlia 3nm narrowband filters and a ZWO LRGB filter set installed.
I’m curious if there is a way for me to contribute to this society. I’m familiar with the basics of photometry. However, I do not know if there is a way to make use of these filters. What I know is that UBVRI filter is preferred but OSC can be used. But what about LRGB filters with a mono camera (like figuring out coefficients)? Is there a guide that can get me started?
Your RGB filters have similar (not identical) bandpass as the photometric RVB filters. You would measure your targets with respect to the Johnson Cousins (JC) RVB comp star magnitudes but report the non-transformed target magnitudes as TR, TG, TB magnitudes.
You could, in fact, generate transformation coefficients for your filters and report the transformed JC RVB magnitudes.
I use SVbony CCD filters with ZWO ASI432MM mono camera. Filter G gives good agreement with V, if star is not too red. I mark results as TG. B and R filters differ from Johnson’s very noticeably, and I do not use them. In special cases I use unfiltered images as CR - indeed points are close to standard R.
Even if you plan to determine TG magnitudes it is useful if you can to determine you Tv_bv transformation coefficient, as this provides a measure of how closely your G filter perfoms to a Johnson V filter.
It may be important. For example the Tb_bv for my G filter is about -0.145. Thus, if the B-V difference between a variable and the comp star is 1 mag unit, the error due just to the properties of you G filter will be 0.145 mag. If the B-V difference is 0.2 mag units, the error will 0.029 mag.
Of course, your filters may be quite different from mine.