[Aavso-photometry] Question on ASAS182612 Campaign

[arne]

Greg Crawford wrote:
> Alert notice 351 refers to the ASAS182612 Campaign and makes the following
> comment on comparison stars:
> 
> 
>>If you are going to use a single comparison star along with a check star, we
>>recommend using:
>>ID       RA(J2000) DEC           V     B-V    V-Rc   Rc-Ic  V-Ic
>>comp  18:26:09.44 +12:17:37.2  11.914  0.748  0.444  0.432  0.876 check
>>18:26:23.68 +12:15:47.2  10.892  0.665  0.383  0.358  0.738
> 
> 
> The software I use (MPO Canopus) can use up to 5 comparison stars. I have vague
> recollections of a recommendation on this list to use only one comparison star
> so that corrections can be made more easily. Is it recommended in this campaign
> that only *one* comparison star be used, (with check star, of course), for
> reduced measurements?
> 
If you are using the BVRI photometry from VSP for this field, you
are given "permission" to use ensemble techniques for this campaign.
Likewise, for GJ436, you can use ensemble techniques.  These fields
have high-quality SRO calibration, so all stars are on the same
system. Be sure to include a comment indicating ensemble.  For all
other fields, wait until we get our new file format published
and available from the software vendors.
Arne