Magnitude Field format

Affiliation
American Association of Variable Star Observers (AAVSO)
Wed, 02/18/2015 - 16:43

Hi Sebastian,

Great to see this forum.

I wonder could you clarify what 'Mag. range 12.6 (0.52) V'  means for the star ASAS J075335-2417.8 ?

I guess it could mean:

The range is 12.6 mags with an error of 0.52

or perhaps the magnitude itself is 12.6 plus or minus 0.52.

Affiliation
American Association of Variable Star Observers (AAVSO)
Hi John,
I remember a similar

Hi John,

I remember a similar question in another forum a couple of months ago.

12.6 (0.52) V means that the star has a V-magnitude of 12.6 and an amplitude of 0.52 mag. in V.

The 12.6 figure will likely be a mean magnitude for pulsating variables and most likely a maximum magnitude for stars that spend most of the time at maximum like EA-type eclipsing binaries.
In the case of cataclysmic variables it might be the magnitude of the outburst detection plus the outburst amplitude.

There are no error figures in VSX, it all has to do with the star's magnitudes: its variability range if there are two magnitude figures or a magnitude plus an amplitude of variation if there is a minimum magnitude in parentheses.

Cheers,
Sebastian

PS:  Please, for tpics related to VSX, write in the VSX forum not here. We will move this thread there.