SUNSET: 
Two Exoplanets in an Interactive Dance
Two transiting planets of the star Kepler 9 are tugging on each other and swapping orbital energy back and forth. And a third planet may be watching on.
One Star, Seven Planets
European astronomers had found a bustling solar system in the southern constellation Hydrus: a Sunlike star with at least five and probably seven worlds swarming around it.
A Tidal Wave of Exoplanet Candidates
NASA's Kepler mission has found more than 700 stars that seem to have planets crossing their faces, mission scientists have announced. But it will take a lot of followup to separate the real ones from the false alarms.
Wrong-way Planets Confound Theorists
Planet-formation theory has been turned on its head by the discovery of planets that travel around their stars in retrograde orbits.
Exoplanet News Roundup
From little red dwarfs to big blue blazers, stars of all masses seem to form planets robustly. That's just one item from the latest crop of exoplanet news.
Kepler's First Exoplanet Results
NASA scientists announced this morning that the Kepler planet-hunting probe is working great, has produced a slew of results, and is working at high enough precision that it should be able to determine the abundance, or rarity, of Earth-size worlds galaxy-wide.
A Weird, Wonderful Waterworld?
The first super-Earth seen transiting its star has the same density as rocky Earth. Now a second one has a the same mass but a lower density — indicating that it's water almost all the way through, with a massive atmosphere to boot.
And Then There Were 400
Thirty new extrasolar planets are announced, including more super-Earths and some that orbit low-metallicity stars.
CoRoT-7b, the Lava Planet
A "super-Earth" planet discovered last February turns out to be just as dense and rocky as Earth. But with its day side seared to perhaps 2,700°F, there might not be much solid ground to stand on.
Super-Earth "Planet From Hell" Refined
CoRoT-7b, a hot super-Earth orbiting an orange dwarf in Monoceros, had proved to be rocky, not gaseous. It's truly a Dante-like inferno, with liquid-lava temperatures on one side and unearthly cold on the other.
Why Does Exoplanet WASP-18b Exist?
Observers have found a massive planet so close to its star that it orbits in less than a day. Either they were very, very lucky — or theorists really don't understand the inner workings of stars as well as they thought.
Exoplanets' "Demolition Derby"
Within the past 1,000 years or so, two planet-size objects collided around the young star HD 172555 and created a titanic, white-hot fireball whose glassy ashes are still swarming around the star.
Kepler Shows Its Promise
After just 1½ weeks of test observations, scientists are confident that the Kepler spacecraft is well on its way to discovering Earthlike planets around distant stars.
Mapping Starspots by Exoplanet Transits
Astronomers have detected individual starspots by watching exoplanets cross in front of them. New advances may enable extensive mapping of stars' spottedness by this technique, filling gaps left by other methods.
Planetary Preemies?
Protoplanetary disks around three young stars turn out to have large central holes, which were presumably cleared by still-growing Jupiter-mass planets. But there’s a problem: the stars are too young.
At Last, an Exoplanet by Astrometry
After decades of frustration and false alarms, astronomers may finally have a new method in their toolkit for finding planets around other stars: astrometry.
Exoplanet Mapping Tested on Earth
Researchers are developing a method to detect oceans and clouds on planets orbiting other stars. To test this idea, they aimed the telescope aboard NASA’s Deep Impact probe toward Earth, and made a rough map of our world.
Fomalhaut's Disk and Fomalhaut's Spin
Way out in the circumstellar cold, a planet and a rubble disk orbit bright Fomalhaut. Does this have anything to do with the star's own rotation?
Super Sendoff for Planet-Hunting Kepler
After a dramatic and flawless liftoff, NASA's newest space observatory is getting ready to observe a tract of Milky May with a single-minded purpose: find as many alien worlds as it can.
COROT Finds the Smallest Exoplanet Yet
Astronomers have found the smallest transiting exoplanet yet, with a silhouette only about 1.7 Earth diameters wide. It's also the fastest-orbiting planet known, with a "year" lasting 20 hours.
