SUNSET: 
The Fate of Exomoons when Planets Scatter
Planet interactions are thought to be common as solar systems are first forming and settling down. A new study suggests that these close encounters could have a significant impact on the moons of giant exoplanets — and they may generate a large population of free-floating exomoons.
An Eccentric Planet Skims a Giant Star
As part of a major survey of evolved stars, scientists have discovered the most eccentric planet known to orbit a giant. What can we learn from this unusual object before it’s eventually consumed by its host?
A Closer Look at the Worlds of TRAPPIST-1
Two new studies of the seven planets orbiting TRAPPIST-1 shed light on how these worlds formed and what they look like now.
A New Definition for the Biggest Planets?
Scientists now understand where large planets stop and small brown dwarfs begin — a discovery that redefines the word “planet.”
Extra Stars Might Downsize Exoplanets
Follow-up studies of candidates planetary systems found by NASA’s Kepler mission suggest that companion stars make some worlds appear smaller than they really are.
Ringed Disks Don’t Always Mean Planets
Astronomers presenting at the winter American Astronomical Society meeting caution that the features often pointed to as evidence of growing natal planets could form on their own.
Metal-rich Stars Host Closer Planets
Iron-rich stars host planets on closer orbits than their iron-poor siblings, astronomers find. The results could help reveal how planets form.
More Planets in the Hyades Cluster
A few weeks ago, Astrobites reported on a Neptune-sized planet discovered orbiting a star in the Hyades cluster. A separate study submitted at the same time, however, reveals that there may be even more planets lurking in this system.
60-Second Astronomy News: Dec. 20, 2017
This week's roundup of astro news brings us a polar-orbiting planet, a novel way to measure stellar masses, and ginormous convective bubbles on a distant star.
Neural Network Finds 8-Planet System
Scientists have applied a brand of artificial intelligence to data from the exoplanet-hunting Kepler satellite, resulting in the discovery of the first eight-planet system outside our own.
Atmosphere, Not Lava Flows, for Exoplanet 55 Cancri e
Previous studies of 55 Cancri e haven’t been able to determine whether this super-Earth hosts an atmosphere. A new study settles the question.
Planet Orbits Quiet Star 11 Light-years Away
Astronomers have discovered a potentially rocky planet around a red dwarf star just 11 light-years away.
Cool Dust — and More Planets? — for Proxima Centauri
Tantalizing new observations hint that there's a lot more going on in the Proxima Centauri system — the one that hosts the exoplanet nearest Earth — than meets the eye.
Puffed-Up Hot Jupiter Is Surprisingly Dark
Researchers have found that a football-shaped, ultra-hot gas giant that’s being devoured by its host star is also one of the least reflective exoplanets ever found.
An Atmosphere of Heavy Metals
Researchers have found strong evidence of titanium oxide in the atmosphere of a hot giant planet, adding new insights to the complex motions of these planets’ extreme atmospheres.
Four Exoplanets Might Orbit Sun-like Star
Astronomers have used an innovative technique to discover four super-Earth-size planet candidates orbiting Tau Ceti, a Sun-like star 12 light-years away.
Best Exomoon Candidate Yet?
Astronomers have found one of the best exomoon candidates in data collected by the Kepler spacecraft.
New Age Estimate for TRAPPIST-1
A new study suggests that the seven-planet dwarf star could be much older than the Sun.
How Do Earth-Sized, Short-Period Planets Form?
Matching theory to observation often requires creative detective work. In a new study, scientists have used a clever test to reveal clues about the birth of speedy, Earth-sized planets.
Rogue Planets: Not as Plentiful as Thought
A new study finds that rogue planets — those floating free in the galaxy, unbound to any star — are not as plentiful as we once thought.
