Just how good is Kepler at finding planets? We're getting a pretty good idea. In his talk yesterday at the AAS meeting in Washington, William Borucki (NASA Ames) showed a plot of the lightcurve for previously known planet HAT-P-7. The signature of the planetary transit is unmistakable in these data, a well defined dip in the starlight as HAT-P-7 makes the star just a little dimmer by its passage. Kepler's sensitivity is apparent. But the plot is more fascinating still, for in addition to the well defined signature that denotes the dip in starlight caused by the planet moving across the face of the star, Kepler also saw a second dip. That one was caused by the light of the planet being blocked by the star itself. It's a tiny dip, but one readily demonstrated in Borucki's chart, and it tells us that Kepler is living up to expectations in terms of finding faint signals. We all hope, of course, for a future finding, the faint signal of a terrestrial world, preferably one in the habitable...

The American Astronomical Society's 215th national meeting will involve some 3,500 attendees, with more than 2,200 scientific presentations on the program, but this morning the buzz is all about Kepler and the early results to be announced today. William Borucki (NASA Ames) spoke at 0830 to announce the first planets discovered by Kepler, five exoplanets (none smaller than Neptune), that include what appears to be a highly irradiated 'Neptune' and a second planet (Kepler 7b) that is the least dense world ever discovered, with a density similar to styrofoam. It, along with three other new exoplanets, gives us insight into planets with densities substantially lower than what we expect from gas giants. Borucki also described another unusual find, Jupiter-sized objects that are hotter than the stars they orbit. A live stream from the AAS is available here, and a Twitter stream at #aas. The paper from Borucki et al. will be published online by Science on Thursday January 7. Later today,...