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V reference stars - What exactly is the value in () with superscript

MJHN
Affiliation
British Astronomical Association, Variable Star Section (BAA-VSS)
Thu, 05/11/2017 - 13:13

I have been using the AAVSO reference stars (mostly the V reference stars)  I notice some in brackets figures like (0.075) superscript 29.

The 29 is APASS but is this a difference with their identified values?

 

All the best

John

 

HQA
Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 05/11/2017 - 13:38
photometry table format

hi John,

There are three pieces of information given for every magnitude in the table:

The actual magnitude

The photometric error (in parentheses)

The source of that information (superscript)

Along with a cross-reference table at the bottom.  So for AF And, for example, the first sequence star has a label of 76, a photometric magnitude of 7.559, an error of 0.032, and a source of 1 (Tycho2).

The (B-V) color shown in the table does not have a corresponding source reference number because it is a derived quantity: the B magnitude minus the V magnitude.  Those two magnitudes might come from different sources, so giving a single ID is not correct.

I hope that helps!

Arne