Check and comparison stars

[Guest]

I've been playing around with a number of photometry packages.  The first is AstroImageJ which allows you to selected a target star and a number of comparison stars. The other package is called MUNIWIN. This package allows you to select a target star.  It only allows me to select one comparison star but any number of check stars. What's the difference between a check star and a comparison star?

Cheers

Steve

 

[robin_astro]

Comparison stars are used to calculate the brightness of the target (and check) stars.  Several comparisons can be combined to form an "ensemble" a sort of super comparison star which can improve accuracy and precision.

Check stars are normally just to check the precision and accuracy of the measurement, useful for checking stability eg during a long time series, where the check star graphs should be flat (multiple comparison stars can also be used as check stars, looking for agreement between them)

Cheers

Robin

Edited December 22, 2020 by robin_astro
typo

[andrew s]

Check star also warns you if you comparison star(s) is, unexpectedly,  varying.

Regards Andrew 

Edited December 22, 2020 by andrew s