Accreting Black Holes: Near & Far
4U 1755-388 and AT2020ocn, though these may seem like incongruous codes, they in fact mark the names of two differing, accreting black holes. 4U 1755-388 was discovered lying near the center of our Galaxy in 1971 as a stellar mass black hole and remained very active until 1995 when it entered a quiescent, or dormant, stage for 25 years until April of 2020 when a new X-ray outburst was recorded. On the other hand, AT2020ocn is a much more distant super massive black hole, and was discovered more recently in the same month that 4U 1755-338’s outburst occurred, and created an unexpected tidal disruption event, which occurs when a super massive black hole destroys a star that got too close for comfort due to incredible gravitational field of the black hole.
