From this document:
https://www.aavso.org/aavso-extended-file-format
It stipulates that CMAG and KMAG are as follows:
CMAG: Instrumental magnitude of the comparison star
KMAG: Instrumental magnitude of the check star
However, when reading through the examples on that same page:
Example 2 ("A little more information"):
#NAME,DATE,MAG,MERR,FILT,TRANS,MTYPE,CNAME,CMAG,KNAME,KMAG,AMASS,GROUP,CHART,NOTES
SS CYG,2450702.1234,11.235,0.003,B,NO,STD,105,10.593,110,11.090,1.561,1,X16382L,na
The above example does not use an instrument magnitude. Instead, CMAG is given as 10.593 and KMAG as 11.090, which would seem to be STD mag.
I suppose it would not ordinarily matter, but when applying transformation coefficients it is necessary to know the instrument magnitude of the comps, yes?
Your are correct that instrumental mags are expected for records submitted that are not ensemble.
Note that just because the reported Cmag and Kmag look very close to the std mag, you don't know that they are not instrumental: the zero point may be set where ever you want.
But it is suspicious.
More alarming is that I can not find labels 105 and 110 in chart X16382L.
https://app.aavso.org/vsp/api/chart/X16382L/
I will investigate this later this week and maybe see that the example gets redone.
Thanks for the sharp eyes!
George
>More alarming is that I can not find labels 105 and 110 in chart X16382L.
I think it is because it is an older chart and, it seems that sometimes AAVSO modifies field stars over the years.
For example, if you go to the table of standard fields:
https://app.aavso.org/vsd/stdfields
It says that M67 has 211 standard stars. But in truth, when you click on M67, only 178 standard stars are returned in the table. Same is true with many other standard fields: Melotte 111 has a displayed count of 92 stars, but only 84 are returned in its table. SA104 has a displayed count of 34 but only 15 are returned in its table. SA35 has a display count of 18 and only 12 in its table. Many more examples like this. So perhaps originally the display count did match the actual field table count, but at some point updates were done and stars removed, and now the display count no longer matches the actual count of field stars.