With #3 recently discovered in the analysis during preparation of Gaia DR4 data, there are now 3 black holes in the Gaia catalog. Or more precise, 3 binary systems consisting of a companion star and a likely stellar-mass black hole.
So I took the opportunity to capture the corresponding starfields with the new IAS remote telescope “Dieter” at Hakos, Namibia. The images only show the companion stars, of course. ;-)
Regarding the BH3 image, at first I wasn’t sure whether I found the right object, as the catalog gives the coordinates RA=19h39m18.7115472s, DEC=+14d55m54.010992s and the read-out in Pixinsight showed ICRS RA=19h39m18.68s, DEC=+14d55m50.3s. But thanks to the discussion with Ulrich Bastian I found out that it is necessary to take into account the large proper motion of the object, which results in almost 4″ deviation in declination. Calculating the current position for 2024.5 with Astropy yields RA=19h39m18.66368537s DEC=+14d55m50.2085012s.
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