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Star index for stars?

Star index for stars?  

  By: Chiara Battistini on July 5, 2021, 7:45 p.m.


I want to get all the stars in a certain area: how am I supposed to use the star index? 1 is star, but I don't get that many stars so I wonder from  which 0.X value I can consider it star enough. Any help?

Re: Star index for stars?  

  By: Christopher Onken on July 6, 2021, 12:54 p.m.

Dear Chiara,

the CLASS_STAR we include in the master table is the maximum value reported by Source Extractor from any image of that object. It's well documented that CLASS_STAR trends towards 0.5 as the signal-to-noise gets low, so the answer will depend on the magnitude range you're interested in.

But from the nearly 600,000 stars in GALAH DR3 (magnitudes 9-16), more than 95% have CLASS_STAR > 0.9.


Christopher Onken

SkyMapper Team