SUNSET: 
The Star That Changed Our Universe
Modern observers have revisited a dim variable star in the Andromeda Galaxy whose discovery in 1923 rocked the astronomical world.
Black Hole Gobbles Star
A powerful Gamma Ray Burst captured by the Swift space telescope earlier this year gives astronomers a unique chance to study tidal disruption.
The Earliest Black Holes
Combining data from the deepest images ever taken in visual/infrared wavelengths and X-rays, astronomers have discovered some of the earliest black holes in the universe.
Closeup of a Black-Hole Powerhouse
Come along with radio astronomers as they zoom in on the powerful, high-energy jets of Centaurus A and the supermassive black hole at its heart.
Best-yet Value for Universe's Expansion
A new study with the Hubble Space Telescope pins down the universe's expansion rate with unprecedented accuracy.
A Galaxy when Galaxies Were Young
News media worldwide are reporting today on the new "farthest galaxy ever found," but the discovery is not quite as definite as it’s being made out.
Shining New Light on "Hanny's Voorwerp"
A mysterious, galaxy-size cloud of glowing gas, discovered by a Dutch schoolteacher in 2007, is teaching cosmologists a thing or two about how quasars work.
The Most Distant Galaxy Cluster
Many instruments working together have profiled a baby galaxy group, seen not long after the Big Bang, of the kind that probably evolved into our Milky Way.
Starry, Starry, Starry Night
Two astronomers report that small, dim red-dwarf stars are far more abundant in elliptical galaxies than thought — so much so that the total number of stars in the universe is likely three times higher than previous estimates.
Cosmology's Distance Record Shattered
It's official: a dim blip spotted last year by the Hubble Space Telescope is a primordial galaxy that blazed to life only about 600 million years after the Big Bang — and that means it's more than 13 billion light-years from Earth.
A New Twist on Dark Energy
Careful observations of the galaxy cluster Abell 1869, so massive that it bends the light from dozens of more distant galaxies, have given cosmologists a powerful new tool in their quest to understand dark energy.
Planck's View of the Universe
A new all-sky map is showing cosmologists both the nearby, current universe and the faint echoes from its creation 13.7 billion years ago.
Last “Missing” Normal Matter Is Found
Thin, elusive gas between the galaxies makes up about half of all the normal matter in the universe — neatly completing the inventory.
Herschel's Cold, Wonderful Universe
European astronomers are ecstatic about the results they're getting from an infrared space observatory launched a year ago.
A New Take on M81's Halo
Astronomers have now clearly resolved a halo of old stars surrounding a well-known galaxy in Ursa Major. But they're not sure how it got there.
Hubble Confirms Dark Energy's Clout
Thanks to a huge photographic survey undertaken by the Hubble Space Telescope, cosmologists have used the distorted shapes of primordial galaxies to "weigh" the distribution of unseen matter in the early universe and confirm the existence of the mysterious "dark energy."
Supernova Mystery Remains Just That
Despite a recent claim, astronomers still don't understand an important class of exploding stars.
Spiral Galaxies Exist — But Why?
New observations of the early universe, combined with models of how galaxies formed and collided in the eons since, are helping cosmologists understand why so many beautiful pinwheels dot the sky.
WMAP Refines "Precision Cosmology"
With seven years of data, the WMAP cosmology satellite has refined the age of the universe and other key cosmic parameters. The results strengthen the "standard model" of inflationary cosmology.
Dark Matter and Dark Energy Update
From the Milky Way's halo to the far reaches of the cosmos, the two dominating components of the universe are revealing more hints about themselves.
