SUNSET: 
The Knife Edge Galaxy Throws Astronomers For a Loop
A 2008 image captured a stunning double loop of stars around an edge-on galaxy. Now, astronomers are questioning whether one of those loops exist.
White Dwarf’s Whirlwind Spin Drags Spacetime
Astronomers have used observations of a tight white dwarf-neutron star pair to confirm an aspect of Einstein's general theory of relativity.
Hubble Sheds Light on Dark Matter and Cosmic Expansion
The Hubble Space Telescope, which will celebrate its 30th birthday this April, has images cosmic mirages that yield two remarkable cosmological results.
Mark Your Calendar: Stellar Fireworks Predicted for 2083
According to Bradley Schaefer (Louisiana State University), the 11th-magnitude variable star, V Sagittae, will outshine Sirius and maybe even Venus — despite its distance of some 7,500 light-years.
European Mission Launches to Examine Alien Worlds
The European Cheops mission launched Wednesday on a mission to improve our understanding of hundreds of known exoplanets.
How a White Dwarf Is Vaporizing Its Giant Planet
Astronomers have long suspected that white dwarfs eat their planetary companions. Now, indirect observations show the process in action.
Heavyweight Black Hole Find Mystifies Astronomers
Observations of a star have found it orbiting an unexpectedly massive black hole. If the discovery pans out, it would change our understanding of how massive stars die.
Planet WASP-12b Might Be on a Death Spiral into its Parent Star
A mere 3 million years from now — a cosmic eye-blink away — the star WASP 12 might consume its exoplanet WASP-12b.
Have Astronomers Detected Exomoons At Last?
Have astronomers detected two giant exomoons? The answer depends on how convincing you deem newly presented results — and how you define a moon.
Radio Survey Maps Hundreds of Thousands of New Galaxies
The LOFAR survey, based in The Netherlands, has released a bonanza of new sources. And with only 2% of the sky covered so far, this is only the beginning.
Gravitational-Wave Observatories Bag Four Black-Hole Collisions
A re-analysis of data from LIGO and Virgo brings the number of gravitational-wave detections to 11, including the most distant and most powerful black-hole merger yet discovered.
“Fast Supernovae” Begin to Reveal Their Secrets
Astronomers have discovered 72 fast and furious explosions, possibly supernovae blasts cloaked in cocoons of ejected gas.
Primordial Chill Hints at Dark Matter Interactions in Early Universe
A simple experiment has detected a signal from the first stars forming just 180 million years after the Big Bang. The observations have intriguing implications for the nature of dark matter.
Orderly Dwarf Galaxies Challenge Cosmological Wisdom
Most of the dwarf galaxies around Centaurus A appear to be orbiting the giant galaxy along a single plane — a result not predicted by current cosmological models.
Dark Energy Survey Releases First Three Years of Data
Results from the first data release of the Dark Energy Survey include eleven new stellar streams in the Milky Way galaxy.
Astronomers Catch Gravitational Waves from Colliding Neutron Stars
Spacetime ripples from the neutron star smash-up usher in the age of multi-messenger astronomy.
Fourth Gravitational Wave Event Detected
Teaming up with LIGO, Europe’s Virgo detector has bagged its first gravitational waves. The three-observatory detection enabled scientists to better pinpoint the merging black holes’ location.
KAGRA: Japan’s Underground Einstein Wave Detector
On June 1, U.S. and European physicists published the latest results in their quest for gravitational waves — tiny ripples in spacetime, generated by energetic events like the collision and merger of distant black holes. Meanwhile, a new gravitational wave observatory is under construction in Japan. Sky & Telescope Contributing Editor Govert Schilling visited the KAGRA detector in 2016.
Homing in on the Source of a Mysterious Fast Radio Burst
Ground- and space-based observations have now shed intriguing new light on a mysterious radio source more than 3 billion light-years away.
Road Tripping Space: Visiting Meteorites in Africa
Traveling through space can be a bumpy ride! Join Govert Schilling on a scenic road trip across southern Africa filled with craters and meteorites.