Overview
- GW241011 (Oct. 11, 2024) involved black holes of about 17 and 7 solar masses roughly 700 million light-years away, with the larger among the fastest spinners ever observed.
- GW241110 (Nov. 10, 2024) came from about 2.4 billion light-years and featured a primary black hole spinning opposite to its orbital motion, a configuration reported for the first time.
- The large mass asymmetries and unusual spins in both events provide tantalizing evidence for hierarchical, second-generation formation in dense stellar environments.
- GW241011’s high-precision signal matched the Kerr rotating–black-hole solution, included a clearly seen higher harmonic observed only for the third time, and upheld general relativity with record accuracy.
- The rapid spin persisting in GW241011’s primary rules out a wide range of ultralight boson masses, as the O4 run approaches its conclusion with roughly 300 black-hole mergers cataloged and further detector upgrades planned.