It's Official: There's a Black Hole on the Loose in Sagittarius

Go to http://ground.news/sou for a better way to stay informed. Subscribe for 40% off unlimited access to worldwide coverage through my link. After 11 years of rigorous surveys, astronomers have confirmed that there really is a black hole on the loose in Sagittarius. All Episodes of SOU Discoveries: https://sou42.co/SOU-discoveries ━━━━━━━━━━━━ ⏳ CHAPTERS 00:00 Intro 01:31 The Invisibility Problem 03:44 The Star That Brightened 400 Times 05:55 Not So Fast! 11:29 Eleven Years of Proof 13:49 The Road Ahead ━━━━━━━━━━━━ REFERENCES: 📌 The original discovery (Sahu et al. 2022, ApJ 933, 83) "An Isolated Stellar-mass Black Hole Detected Through Astrometric Microlensing" — https://arxiv.org/abs/2201.13296 📌 The competing analysis (Lam et al. 2022, ApJL 933, L23) "An Isolated Mass-gap Black Hole or Neutron Star Detected with Astrometric Microlensing" — https://arxiv.org/abs/2202.01903 📌 The Berkeley re-analysis (Lam & Lu 2023, ApJ 955, 116) "A Re-analysis of the Isolated Black Hole Candidate OGLE-2011-BLG-0462/MOA-2011-BLG-191" — https://arxiv.org/abs/2308.03302 📌 The confirmation, this episode's main paper (Sahu et al. 2025, ApJ 983, 104) "OGLE-2011-BLG-0462: An Isolated Stellar-mass Black Hole Confirmed Using New HST Astrometry and Updated Photometry" — https://arxiv.org/abs/2503.07820 ━━━━━━━━━━━━ Created By: Rishabh Nakra Narrated By: Jeffrey Smith