The Million Quasars (Milliquas) Catalogue, v6.4
  Announcing the release v6.4 of the Milliquas (Million Quasars) quasar
catalogue which presents all published quasars to 11 December 2019, including
SDSS-DR16. Its totals are 757,991 type-I QSOs/AGN and approx 1.1M
high-confidence (80%+ likelihood) quasar candidates from SDSS-based & AllWISE
photometric quasar catalogs, plus all-sky radio/X-ray associated candidates
available only here. Type-II and Bl Lac objects are also included, plus
candidates/galaxies with double radio lobes (so calculated), bringing the total
count to 1,968,377. Gaia-DR2 astrometry is given for most objects. The
catalogue is available on its home page and on NASA HEASARC.
