A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth's mass into a sphere about 12 miles across, or similar in size to Manhattan Island.
When did the first stars and galaxies form? How brightly did they burn? Scientists hope to answer to these questions with the Cosmic Infrared Background ExpeRIment (CIBER).
This composite of images from NASA's Chandra X-ray Observatory shows the remnant of Kepler's supernova in low (red), intermediate (green) and high-energy (blue) X-rays.
The giant barred spiral galaxy NGC 6872 is 522,000 light-years across from the tip of one outstretched arm to the tip of the other, making it about 5 times the size of our home galaxy, the Milky Way.
Most neutron stars rotate rapidly, some spinning hundreds of times per second. Scientists have found an unusual, young neutron star with an extremely slow spin - just one turn every 17.7 minutes.
'Tis the season for holiday decorating and tree-trimming. Not to be left out, astronomers using the Hubble Space Telescope have photographed a festive-looking nearby planetary nebula called NGC 5189.
NGC 5253 is located about 12 million light-years from Earth in the constellation of Centaurus. These types of galaxies harbor very active star-forming regions, giving rise to their blue color.
NGC 3344 is a glorious spiral galaxy around half the size of the Milky Way. The galaxy features an outer ring swirling around an inner ring with a subtle bar structure in the center.
A dying star is throwing a cosmic tantrum. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
Like photographers assembling a portfolio of best shots, astronomers have assembled a new, improved portrait of mankind's deepest-ever view of the universe.
NGC 4634 is a spiral galaxy seen exactly side-on. Its disk is slightly warped by ongoing interactions with a nearby galaxy, and it is crisscrossed by clearly defined dust lanes and bright nebulae.
Imagine a dead star the size of a city and with more mass than our sun. Now imagine two of them smashing into each other, generating a blast bright enough to outshine an entire galaxy.
Messier 10 is a ball of stars that lies about 15,000 light-years from Earth. About 80 light-years across, it should appear about two thirds the size of the moon. Find out why it doesn't...
Wispy tendrils of hot dust and gas glow brightly in this ultraviolet image of the Cygnus Loop Nebula, a supernova remnant, taken by NASA’s Galaxy Evolution Explorer.
This all-sky image shows the distribution of galactic haze seen by ESA's Planck mission at microwave frequencies superimposed on the high-energy sky, seen by NASA's Fermi Gamma-ray Space Telescope.
Eta Carinae is one of the closest stars that is likely to explode in a supernova in the relatively near future (though in astronomical timescales, that could still be a million years from now).