It's official: our solar system has eight planets, and Pluto is not one of them according to the International Astronomical Union.
Telescopes as large as 20, 30, and even 100 meters are now on the drawing boards.
The latest results from two comprehensive galaxy surveys independently confirm the important role of dark matter and dark energy in the evolution of the cosmos.
Like mosquitos hovering around a mountain, small black holes swarm around the supermassive black hole in the core of the Milky Way. According to a team led by Michael P. Muno (University of California, Los Angeles), there may be as many as 20,000 stellar-mass black holes lurking within a three-light-year-wide sphere surrounding the 3-million-solar-mass behemoth…
Orbiting Beta Pictoris farther than Saturn orbits the Sun, an unseen planet is apparently shaping the star's asteroid belts.
Fifteen thousand humble little antennas will work in concert to form one of the world's most powerful astronomical instruments.
Tiny-tiny galaxies and activity minima in Sun-like stars.
What looks like a supernova remnant on the far side of the Milky Way could be the shattered remains of something bigger.
The first stars to light up the universe after the Big Bang did not appear in a simple, expected way.
Taking its deepest-yet look into the infrared sky, the Spitzer Space Telescope pulls some mysterious objects out of hiding.
Polaris is not only a variable star, its variations are varying. And no one quite knows why.
In the span of three weeks, astronomers twice smashed a record that had stood since 1979.
It make a dying double star to create a planetary nebula and to make it light up.
By stitching together 78 high-resolution Hubble Space Telescope photos, astronomers have created Hubble's widest "deep field."
Astronomers are trying to hunt out everything that exists within 32 light-years of Earth.
Did a globular star cluster passing through the Milky Way cause new stars to form?
The Sloan Digital Sky Survey has helped provide astronomers with a more detailed map of the universe.
Radio links with the Cassini spacecraft show Einstein's general theory of relativity to be correct to one part in 40,000. But new physics could show up just a little beyond.
A few days ago we got hit by the nearest major gamma-ray burst ever. It was bright enough that many amateur astronomers imaged it.
Spiral rings appear in a young star's dusk disk that's ten times larger than our solar system.
New images from the Hubble Space Telescope reveal unprecedented detail in a light echo expanding around an explosive variable star in Monoceros.
If David J. Tholen (University of Hawaii) is right, Pluto was probably hit by a small Kuiper Belt object in the not-too-distant past. One consequence of that collision, he argues, is seen in the planet's motion Pluto and its satellite Charon now waltz around each other in slightly out-of-round orbits. And since tidal forces…
For several years now, astronomers have studied the farthest reaches and earliest days of our universe using the full sensitivity of large telescopes both in space and on the ground. These “deep fields” have revealed faint, enigmatic features dubbed Extremely Red Objects (EROs) that some researchers claim to be more than 13 billion…
Using adaptive optics, a new solar telescope in the Canary Islands is taking the best-ever pictures of the Sun.
Astronomers have clocked a star orbiting the black hole at the Milky Way's center, revealing its mass.