Astronomy

Taking advantage of a cosmic "double lens," astronomers resolved more than 40 individual stars in a galaxy so far away its light dates back to when the universe was only half its present age.

Billions of years ago, two icy worlds collided. Rather than destroying each other in a cosmic catastrophe, they spun together like a celestial snowman, finally separating but remaining forever linked in orbit. This is how Pluto and its largest moon, Charon, originated, a U of A study finds.

The U of A delivered $955 million in total research activity last year, ranking among the top 20 public research institutions and remaining No. 1 in astronomy and astrophysics. University officials project research activity exceeded $1 billion in fiscal year 2024 and are submitting the data to the National Science Foundation for review. The official number will be confirmed in the fall.

For the first time, one of the Giant Magellan Telescope's primary mirror segments, produced at the U of A Richard F. Caris Mirror Lab, has been integrated into a support structure that will maintain the mirror's shape once mounted on the telescope.

A group of researchers, including U of A astronomers, observed the atmosphere of a hot and uniquely inflated exoplanet using NASA's James Webb Space Telescope.

Sept. 22 marks the official first day of fall this year, but that's not always the case. The start of fall and spring is determined by an astronomical phenomenon called an equinox, when the sun is positioned exactly above Earth's equator. Jose Daniel Castro-Cisneros, a physics graduate student, explains how equinoxes work.

In the Best Global Universities rankings, UArizona earned its best scores in space sciences, ranking No. 8 overall, No. 6 in the U.S. and No. 2 among public universities.

How much time do planets have to form from a swirling disk of gas and dust around a star? A new University of Arizona-led study gives scientists a better idea of how our own solar system came to be.

The observations will help astronomers refine their theories about the processes involved in planet formation and shed light on what our sun did when it was very young.