SUNSET: 
Faint Repetitions of an Extragalactic Burst
New evidence deepens the mystery of fast radio bursts (FRBs), the brief flashes of radio emission stemming from unknown sources beyond our galaxy.
An Extreme Pulsar Seen in Gamma Rays
One of the fastest spinning radio pulsars known has now been detected to pulse in gamma rays, too. What can we learn from these new observations?
The Appearance of a Black Hole’s Shadow
In April of this year, the Event Horizon Telescope captured the first detailed images of the shadow of a black hole. In a new study, a team of scientists has now explored what determines the size and shape of black hole shadows like this one.
Should We Blame Pulsars for Too Much Antimatter?
A new study suggests that pulsars are not the source of an unexpected surplus of antimatter particles detected by a space-based experiment. Dark matter remains a viable alternative explanation.
Two Eyes to Hunt Stray Planet Masses
How can we measure the masses of free-floating planets wandering around our galaxy? A new study identifies one approach that combines the power of two upcoming missions.
Are There More Stars Like Boyajian’s Star?
Remember KIC 8462852, better known as Boyajian’s star (or you may have seen it referred to as the “alien megastructure” star)? We still don’t have a definitive explanation for this source’s odd behavior — in part because we thought that Boyajian’s star was one-of-a-kind.
Planetary History Written in Saturn’s Rings
Saturn is subtly pulsing and oscillating — and those oscillations impose a pattern on its rings that could tell us about the planet’s history.
A Nearby Stellar Stream Gets Carded
The stellar stream Pisces–Eridanus may try to pass itself off as a billion years old, but scientists are calling its bluff.
An “Impossible” White Dwarf Identified in Kepler Data
Meet the white dwarf that defies all expectations.
Exomoon or No Exomoon?
Last October, the first discovery of a potential exomoon was announced. But is Kepler-1625b-i an actual moon in another solar system? Or just an artifact of data reduction?
A Link Between Fast Radio Bursts, Magnetars, and Supernovae?
What causes the bizarre, extragalactic fast radio bursts we’ve detected over the last decade? An unusually bright supernova may hold the answer.
Hubble Confirms Interstellar Buckyballs
From a jumble of confusing clues in Hubble observations of interstellar space, scientists have picked out evidence of a celebrity molecule: ionized Buckminsterfullerene, or buckyballs.
Inflating a Super-Puff Planet
Super-puffy exoplanets are a problem. They shouldn’t exist — and yet we've detected half a dozen of them. Here's what theory might be getting wrong.
Dwarf Galaxy or Giant Globular Cluster?
AAS Nova brings us the story of a newly discovered cluster of stars. But the jury's out as to whether this group is a typical ancient stellar cluster or something more.
Taking Note of Molecules in Space
What do methylidyne, cyanamide, vinyl alcohol, and rugbyballene all have in common? They’re all molecules that have been detected in space — and they’re all included in a recent census of our universe’s chemical makeup.
Exploring the Escaping Atmosphere of HAT-P-11b
The atmospheres of planets close to their host stars live a tenuous existence. New observations from the Hubble Space Telescope show signs of a Neptune-like exoplanet’s atmosphere being eroded away.
Searching for Alien Needles in the Cosmic Haystack
Humanity’s search for signs of extraterrestrial intelligence has been underway, in one form or another, for decades. But how much searching have we really done?
A Black Hole X-Ray Binary Rises
New observations have captured a feeding black hole in our galaxy as it bursts onto the scene.
Speeding White Dwarfs May Point to Past Explosions
A recent study has discovered three of the fastest stars — white dwarfs — known in the Milky Way. But these stars may be more than just speeders — they might also be evidence of how Type Ia supernovae occur.
Two Explosions with Similar Quirks
High-energy radiation released during the merger of two neutron stars last year has left astronomers puzzled. Could a burst of gamma rays from 2015 help us to piece together a coherent picture of both explosions?