A New Galactic Yardstick

A New Galactic Yardstick

We can measure the expansion of the universe with velocities and distances of extragalactic objects. But measuring distances is tough! The authors of this paper have developed a new technique for measure the distances of AGN using the “echo” of light from heated dust.

A star with a fake ID?

A star with a fake ID?

Most binary stars probably formed at the same time, meaning all stars in the same system should have the same age. The authors of this paper analyze a stellar binary system where one star appears to be lying about its age, as one star appears 3 billion years older than its companion.