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Seeing and sky brightness

Seeing and sky brightness affect both the completeness of the SDSS and the accuracy of its star/galaxy separation. Seeing is defined here as the effective width of the point spread function (see section 4.3 of the EDR paper). The following plots show the fraction of DR1 fields exceeding a given seeing and sky brightness.

SeeingSky brightness

These are the r-band quartiles:

Parameter Lower quartile Median Upper quartile
PSF width 1.58" 1.43" 1.30"
Sky brightness 20.70 mag 20.86 mag 21.03 mag

Last modified: Tue Feb 17 18:41:43 CST 2004