Exceptionally massive and bright, the earliest stars changed the course of cosmic history
To make a star, gas and dust must fall inward. So why do astronomers see stuff streaming outward?
Less massive than stars but more massive than planets, brown dwarfs were long assumed to be rare. New sky surveys, however, show that the objects may be as common as stars
Sunspot cycles--on other stars--are helping astronomers study the sun's variations and the ways they might affect Earth
Shock waves from the sun can trigger severe turbulence in the space around earth, endangering satellites and astronauts in orbit. A novel spacecraft is showing how space storms develop
When two stars smash into each other, it can be a very pretty sight (as long as you're not too close by). These occurrences were once considered impossible, but they have turned out to be common in certain galactic neighborhoods
Several years ago astronomers came across a new type of starthat spews out unusually low energy x-rays. These so-called supersoft sources are now thought to be white dwarf stars that cannibalize their stellar companions and then, in many cases, explode
Every time a gamma-ray burst goes off, a black hole is born