For those who watch gravitational waves roll in from the universe, GW250114 is a big one. It’s the clearest gravitational wave signal from a binary black hole merger to date, and it gives researchers an opportunity to test Albert Einstein’s theory of gravity, known as general relativity.

“What’s fantastic is the event is pretty much identical to the first one we observed 10 years ago, GW150914. The reason it’s so much clearer is purely because our detectors have become much more accurate in the past 10 years,” said Cornell physicist Keefe Mitman, a NASA Hubble Postdoctoral Fellow at the Cornell Center for Astrophysics and Planetary Science in the College of Arts and Sciences.

Mitman is a co-author of the paper analyzing the wave, “Black Hole Spectroscopy and Tests of General Relativity with GW250114,” published in Physical Review Letters. It was written by the LIGO Scientific Collaboration, the Virgo Collaboration in Italy and the KAGRA Collaboration in Japan. Cornell researchers have been leading contributors to the LIGO-VIRGO-KAGRA project since its beginning in the early 1990s.

Researchers from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and the Institute of Space Studies of Catalonia (IEEC), in collaboration with the Institute of Astrophysics of the Canary Islands (IAC), have led the most extensive observational study to date of runaway massive stars, which includes an analysis of the rotation and binarity of these stars in our galaxy.

This study, published in the journal Astronomy & Astrophysics, sheds new light on how these stellar “runaways” are ejected into space and what their properties reveal about their fascinating origins.

Runaway stars are stars that move through space at unusually high speeds, drifting away from the places where they were born. For a long time, the way massive runaway stars acquire these high velocities has remained a mystery to astronomers, who have considered two main scenarios: a violent kick when a companion explodes as a supernova in a binary system, or a gravitational ejection during close encounters in dense, young star clusters.

The NASA/ESA/CSA James Webb Space Telescope has topped itself once again, delivering on its promise to push the boundaries of the observable Universe closer to cosmic dawn with the confirmation of a bright galaxy that existed 280 million years after the Big Bang.

By now Webb has established that it will eventually surpass virtually every benchmark it sets in these early years, but the newly confirmed galaxy, MoM-z14, holds intriguing clues to the Universe’s historical timeline and just how different a place the early Universe was than astronomers expected.

“With Webb, we are able to see farther than humans ever have before, and it looks nothing like what we predicted, which is both challenging and exciting,” said Rohan Naidu of the Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research, lead author of a paper on galaxy MoM-z14 published in the Open Journal of Astrophysics.