Could you submit data taken from images taken through the Astrodon Exoplanet Filter and if so, what filter entry would you use?
Phil and Tim:
1. Sounds easy but not really.
2. Where is the CBB magnitude that you are using as a reference mag with your "CBB" filter? Doesn't exist.
3. I suspect, you will still use a V mag as the reference mag. This will get properly (?) reported as CV by VPhot.
4. In VPhot, you will see the notes field include a note about a non-standard C filter. You should edit this as CBB. It would get reported in all your images/lines in your report. Your filter field will be shown as CV, so you know what reference filter mag you used.
5. IMHO, when the CBB filter was added to the list of acceptable filters, I think all ramifications were not though out!? The CBB is a clear filter with a little extra blocking in the blue end of the spectrum. Is CV actually a filter? No, C is the filter (with no blocking - really for all C filters?) but we understand what is meant because of the description in the file format help document.
6. Most importantly, your mags are not reported as a photometric filter mag (e.g., BVRI).
7. Clear filters in general (including CBB and Luminance) are not photometric filters and the researcher/user knows that the accuracy of the magnitude is suspect.
8. In fact, most researchers understand this and just use the mags (e.g., CV) for temporal analysis of faint targets or exoplanet transit time and depth. They can create/use a mag offset if required.
My recommendation is that you report the filter that took the data. If you used a CBB, report it as CBB. Since the reference magnitude is ambiguous, use V references and say so in a comment.
You can tell VPhot to map CBB to V in your telescope profile. You will need to check the output file and possibly need to edit the filter in the final output. (ie change the V back to CBB in the output file.)
As Ken pointed out, no one will expect good photometry from a CBB filter. But if they do look then the report should be accurate.
As you can see, we have a difference of opinion about how it is best to report it! There are no CBB comp mags, so I'll continue to use CV and put CBB in the notes field. ;-)
You can make your choice!