APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
GW250114: Rotating Black Holes Collide
Explanation: It was the strongest gravitational wave signal yet measured -- what did it show? GW250114 was detected by both arms of the Laser Interferometer Gravitational-wave Observatory (LIGO) in Washington and Louisiana USA earlier this year. Analysis showed that the event was created when two black holes , each of mass around 33 times the mass of the Sun , coalesced into one larger black hole with a mass of around 63 solar masses. Even though the event happened about a billion light years away, the signal was so strong that the spin of all black holes , as well as initial ringing of the final black hole, was deduced with exceptional accuracy . Furthermore, it was confirmed better than before, as previously predicted , that the total event horizon area of the combined black hole was greater than those of the merging black holes . Featured, an artist's illustration depicts an imaginative and conceptual view from near one of the black holes before collision.
| Date | September 24, 2025 |
|---|---|
| Credit | Illustration Credit: Aurore Simonnet ( SSU / EdEon ), LVK, URI; LIGO Collaboration |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



