Category

Photometry

Comparison Stars

Comparison stars are at the heart of photometry.

While photometry seeks to measure the flux changes of a target star, the comparison provides the baseline from which to compare. Without comp stars, it would not be possible to know the flux changes of the target.

It is important that comp stars be stable and un-variable. There are tools available to determine whether a desired comp star is variable or not. The AAVSO has excellent resources for this purpose.

Other software packages such as AstroImageJ (AIJ) provide feed back on randomly selected comp stars.

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