The first gravitational wave detected by LIGO was produced by the merger of two black holes approximately 1.3 billion years ago.
Notes on verification
Confirmed by LIGO/Caltech official press release, MIT News, Scientific American, and LIGO Scientific Collaboration detection page. Minor variance in some later sources (1.4 billion years) but 1.3 billion is the original, officially announced and widely cited figure. [tier=silver indep_score=0.875 clusters=4 claim_tier=notable]
Sources
- The biggest scientific breakthroughs of the last 25 years—and ... (seed:science_and_space)
- https://www.ligo.caltech.edu/news/ligo20160211 (corroboration)
- https://www.ligo.caltech.edu/page/press-release-gw150914 (corroboration)
- https://news.mit.edu/2016/ligo-first-detection-gravitational-waves-0211 (corroboration)
- https://ligo.org/detections/GW150914/ (corroboration)
- https://www.scientificamerican.com/article/gravitational-waves-discovered-from-colliding-black-holes1/ (corroboration)