[Aavso-photometry] [AAVSO-DIS] MagType in the new extended format

[Mark Munkacsy]

Arne, thanks for clarifying that the difference between ABS and DIF is 
not the same as the difference between "all-sky" and "differential". 
But, in the example that's provided for SS Cyg with the new, extended 
format (example number 2), all four measurements have different 
magnitudes listed for the comparison star. As I understand it, the only 
thing that would cause the measured magnitude of the comparison star to 
be anything other than the comp star's reference value would be if an 
ensemble was being used to set the zero point or if this was truly 
all-sky (not differential) photometry. And my reading of that example is 
that an ensemble is *not* being used. (And because a comp star is being 
used, I guess I can conclude that this doesn't represent all-sky 
photometry?) Where am I confused?

- Mark


arne wrote:
> There has been some discussion off-line as to what the MagType
> field actually means in the Extended Format that is used for
> submission of CCD data.  It was my attempt to merge
> two different measurement techniques into a single flag.
>
> ABS means differential photometry, ...  It is a bad name, as
> absolute magnitude means something different to astronomers, but
> it is the 3-letter abbreviation we chose to simplify things.
>
> Arne
>