摘要：Most of the sky has been imaged with NOAO’s telescopes from both hemispheres. While the large majority ofthese data were obtained for PI-led projects and almost all of the images are publicly available, only a smallfraction have been released to the community via well-calibrated and easily accessible catalogs. We are remedyingthis by creating a catalog of sources from most of the public data taken on the CTIO-4 m+DECam and theKPNO-4 m+Mosaic3. This catalog, called the NOAO Source Catalog (NSC), contains over 2.9 billion uniqueobjects, 34 billion individual source measurements, covers ≈30000 square degrees of the sky, has depths of ≈23rdmagnitude in most broadband filters with ≈1%–2% photometric precision, and astrometric accuracy of ≈7 mas. Inaddition, ≈2 billion objects and ≈21000 square degrees of sky have photometry in three or more bands. The NSCwill be useful for exploring stellar streams, dwarf satellite galaxies, QSOs, high-proper motion stars, variable stars,and other transients. The NSC catalog is publicly available via the NOAO Data Lab service.
