SUNSET: 
NGC 6872: The Largest Spiral Galaxy
Our Milky Way ranks near the top in the pecking order of spiral galaxies, but it's no match for an enormous "island universe" in the constellation Pavo that is more than 500,000 light-years across.
Beyond the Standard Model — Or Not
Scientists keep trying to disprove the Standard Model that governs modern physics. And they keep failing.
Hubble Takes Galaxy Census
New observations by the Hubble Space Telescope reveal some of the earliest galaxies in the universe.
Cosmic Web Weeds Dwarf Galaxies
Astronomers have discovered an unexpected explanation for why they can only find a small fraction of the satellite galaxies the Milky Way is supposed to have.
Fermi Detects Cosmic Fog
An international team has used the disappearance of high-energy photons to narrow in on the origin of the light suffusing the cosmos.
Stray Stars Might Solve Infrared Puzzle
A new study suggests that lonesome stars in galaxies’ farthest outskirts contribute to a mysterious, blotchy glow that permeates the sky.
Hubble Goes Deep — eXtremely Deep
The Hubble Space Telescope's newest deep space image reveals 5,500 galaxies in a tiny, dark patch of sky in the constellation Fornax.
Universe is Still Missing its Lithium
New observations of the Small Magellanic Cloud have only heightened the mystery surrounding a decades-long cosmic conundrum: why does the universe have so much less lithium than astronomers think it should?
Science All Around at the IAU
Jay Pasachoff blogs about his experience at the second week of IAU's General Assembly in Beijing, taking in talks on everything from the age of the universe to the history of sunspots.
WISE Detects Blazing Black Holes
Astronomers using data from the WISE all-sky infrared survey have discovered a new class of luminous galaxies in the distant universe. These objects are rare, super-duper bright, and yet totally invisible in visible light.
New Heavyweight Galaxy Cluster
Astronomers have discovered a supermassive galaxy cluster that both meets and challenges expectations for how clusters ought to behave.
Fly Through a 3D Map of the Universe
A mind-boggling 1.5 million galaxies trace out the filaments, clusters, and voids in Sloan Digital Sky Survey's new 3D map of the universe.
Star-Shredder's Brief Pulse
A supermassive black hole spotted last year as it ripped a star apart and spat out a jet had another surprise up its sleeve: a short-lived X-ray heartbeat seen only once before from a galaxy’s central beast.
Dark-Matter Thread Revealed
Scientists have found a dark-matter filament, a strand of the cosmic web that connects clusters of galaxies. It's the first time an individual filament has been detected and is among our first observational glimpses of the universe’s largest structures.
A Windy Early Universe
Winds in the early universe could make radio observations of the first stars and galaxies a little easier, says a new study published in Nature.
The Universe’s Lost Lithium
Astronomers are still struggling with a 30-year-old mystery that puts modern cosmology in a head-to-head clash with stellar observations. A new study may make the problem even worse.
Black Hole Eats Stripped Star
A closely-watched flare from a gargantuan black hole in a distant galaxy has revealed to astronomers not only the mass of the black hole that ate the snack but the type of star that met its end as the meal.
Cosmic Ray Origin Still Mysterious
Observations out of Antarctica support the idea that the most energetic of the superspeedy space particles raining down on Earth are not from gamma-ray bursts. The new result prolongs a long-standing mystery in astrophysics.
Far-out Black Hole Hints
“Star cities” orbiting galaxies may reveal the mass of the gargantuan black hole hidden deep in the galaxy’s heart. The new relation could be more evidence for a large-scale black hole-galaxy link — or, it could mean one of the latest revolutions in astrophysics isn’t the full story.
Hubble Images Stir Up Dark Matter Debate
Dark matter in the "Train Wreck" galaxy cluster (Abell 520) appears to behave in unusual ways. Now, new Hubble images are heating up the debate.