kepler1b

NASA’s orbiting Kepler telescope launched last March.  After analyzing data from the first six weeks of operation, NASA has announced the discovery of at least five new exoplanets, one with the density of styrofoam.  Via skyandtelescope:

Four of the five new worlds are puffed-up hot Jupiters (with 1.3 to 1.5 times Jupiter’s diameter) orbiting very close to their stars. One of them, named Kepler 7b, is among the lowest-density planets yet discovered, with a measured diameter and mass that yield an average density of just 0.17 grams per cubic centimeter (compared to Saturn’s 0.69 and Earth’s 5.52). That’s the density of styrofoam. [...] The other planet is a hot Neptune with about our own Neptune’s density — even though it orbits so close to its star that its surface layer should be roasted to 1,900°C. All five, in fact, should have outer-layer temperatures hotter than lava, and two should be hotter than molten iron. [...] In the first 43 days of data-taking, Kepler found about 175 transit candidates. Fifty of these were scrutinized to find the five planets announced. Some 125 candidates remain, and that’s just from the first six weeks of data. Tidal waves of subsequent data are already in hand.

Kepler is monitoring a small patch of the sky between Vega and Deneb in search of habitable planets in wide, Earth-like, 1 year orbits.  It’s not surprising that the first five planets discovered are hot planets close to their suns with orbits ranging from 3.3 to 4.9 days, as these are easier to spot than more-hospitable planets with wider orbits.  Another optimistic observation gleaned so far is the finding that “Sun-like stars are generally quiescent”, meaning they show little variation in brightness.  If you were hoping for a super solar flare to take out Nic Cage, I suggest you buy some bees instead.

[Pictures via NextBigFuture, with slight alterations]