Over twenty percent of the planets we've found around other stars inhabit binary systems. It's intriguing to take a close look at these. Most of the planet-bearing binaries are what is known as 'wide S-types,' meaning that the companion star orbits the inner star/planet system at a distance of over 100 AU. But take a good look at GJ86b, γ Cephei b and HD41004b. Here we're looking at three planets in close binary systems with a separation between the component stars of 20 AU or less. That separation raises the eyebrows, for Alpha Centauri A and B form a close binary with a semimajor axis of 23.4 AU. We have three ongoing planet hunts around the Centauri stars, Debra Fischer's work being matched by Michel Mayor's team at La Silla and both complemented by a new search based at Mt. John Observatory in New Zealand. So it may not be long -- months, possibly -- before we have some word about planets around these stars. Informing all these searches, though, is the issue of...

Astronomers have obtained a direct spectrum of the exoplanet HR 8799 c, about 130 light years from Earth, and if you watch your definitions, it's possible to call this the first 'direct spectrum' of such a world. I throw in the qualifier because way back in 2004, astronomers using the ESO's Very Large Telescope and the infrared instrument NACO obtained an image and a spectrum of a planet of about five Jupiter masses around a brown dwarf. The question then involved how the two objects formed -- did they form together, like a stellar binary, or did the smaller object form out of the disk around the brown dwarf? Whatever the case, the new work on HR 8799, also conducted with the VLT and NACO, takes us into interesting territory. Up until now, the way we've obtained a spectrum from an exoplanet has been to observe the planet moving directly behind its host star. The spectrum was then derived by comparing the light from the star before and after this event. That method relies, of course,...

Glints of light off oceans or ice caps would be useful indeed as we try to figure out what we're seeing on a distant terrestrial world. One day we'll have the kind of instrumentation that can make direct observations of a planet like this, separating its light from that of its star. A 'terrestrial planet finder' mission that finds sun glints in its data would have identified a planet that could be suitable for life, one with large areas of water or ice. Drake Deming (NASA GSFC) specializes in recognizing features like this in his work as deputy principal investigator for the Extrasolar Planet Observations and Characterization (EPOCH) study, a part of the extended mission of the Deep Impact spacecraft. EPOCH has produced two new videos showing bright flashes produced by sunlight as the Earth is seen to rotate from a distance of about eleven million miles. The idea is to produce a view of the Earth that can be studied in the same way a future planet-hunter spacecraft would study an...

With the American Astronomical Society meeting now wrapped up in Washington, we're left to mull over the highlights, particularly the Kepler results. But the Keck Observatory also contributed compelling exoplanet news in the form of HD156668b, a planet some eighty light years from earth in the direction of Hercules. Working with Keck data, a research team led by Andrew Howard (University of California at Berkeley) has brought us a world that is only four times the mass of Earth, making this 'super Earth' the second smallest exoplanet yet discovered. Addendum: See andy's note below re planets smaller than this one. More on the 'pulsar planets' here. Using the HIRES instrument (High Resolution Echelle Spectrograph) and the 10-meter Keck I telescope at Mauna Kea, the astronomers teased out the presence of the planet through radial velocity methods, which are responsible for the great majority of the planets thus far discovered. The trick is to work down to smaller and smaller worlds...

William Borucki's talk about the early Kepler findings on Monday created the biggest spike in traffic I've ever seen on Centauri Dreams, enough to blow through our memory allocation and crash the site for about twenty minutes. I had to reboot the server and up the memory to get back online, a tribute to the interest Kepler continues to generate in our community. I'm also getting plenty of comments from people at the American Astronomical Society meeting in Washington. If you use Twitter, use the hashtag #aas to join the ongoing stream of short updates. Right now Scott Gaudi's talk on Tuesday is generating the biggest buzz. Gaudi (Ohio State) reported on a gravitational microlensing effort called MicroFUN (Microlensing Follow-Up Network), one we've previously discussed in these pages. The method is well understood: One star occults another as seen from Earth. The light of the more distant star is magnified by the nearer one, and any planets around the lensing star momentarily boost...