HST Guide Star Catalog Non-Stellar Sources in Galactic Coordinates

This image is an Aitoff projection of sources tagged as non-stellar in the HST Guide Star Catalog, with source flux in 15-minute bins. Magnitudes have been recalibrated between the northern and southern hemisphere to account for different wavelength responses in the photographic plates on which the catalog is based.

The density of fuzzy sources along photographic plate boundaries indicates that many of these sources are probably out-of-focus stars.

all-sky image

Picturing the Guide Star Catalog Figure 4