Department of Astronomy

A group of astronomers, including U.Va.'s Craig Sarazin, have observed two groups of galaxies slamming into one another at a speed of about 4 million miles per hour.  The colliding groups will eventually merge and form a single cluster of galaxies; these are the largest objects in the Universe.  Clusters contain as much material as one million, billion stars.  This cosmic train wreck was observed with a number of space and ground-based observatories, including by U.Va. astronomers using the Apache Point Observatory (APO) in New Mexico.  U.Va.

UVa Astronomy graduate student Thankful Cromartie led a paper published in Nature Astronomy detailing the discovery of the most massive neutron star ever observed. This work was conducted along with her advisor Scott Ransom (of UVa and the National Radio Astronomy Observatory) and the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration. The team used pulsar timing — accounting for every rotation of dense, rapidly rotating stellar remnants — to measure the mass of J0740+6620, a 2.89-ms pulsar with a binary white dwarf companion.

While our solar system contains dozens of moons orbiting the planets, there is as yet no clear detection of a moon orbiting an extrasolar planet. A group of astronomers and planetary scientists, led by former UVa graduate student Apurva Oza, have a new paper accepted to the Astrophysical Journal (http://arxiv.org/abs/1908.10732) which shows that these exo-moons may have been hiding in plain sight.

Steve Layman, an amateur astronomer who’s made a career in music, works with the astronomy department to bring telescopes to schools and Scouts. (Photo by Sanjay Suchak, University Communications)