The Hungarian Automated Telescope Network (HATNet) is run out of the Harvard-Smithsonian Center for Astrophysics, with primary stations at Mauna Kea (HI) and on Mt. Hopkins (Arizona). Looking at large fields of stars over many consecutive nights, the automated telescopes involved help astronomers identify the periodic dimming that marks a transiting exoplanet. And with other projects like the Trans-Atlantic Exoplanet Survey (TrES), the XO Project in Maui and the Optical Gravitational Lensing Experiment (OGLE) in Chile operational, transit data are piling up. All of which is useful indeed, for at present we are just nearing 20 transiting planets detected from ground-based observatories. The discovery paper for the most recent HATnet detection makes an interesting point about the size of our sample, declaring it "...still small enough that individual discoveries often advance our understanding of these objects significantly by pushing the limits of parameter space, either in planet...

With the European Space Agency's DARWIN at least a decade off and funding for the Terrestrial Planet Finder as problematic as ever, what would be a suitable interim mission to extend our exoplanet exploration program? COROT is already flying, with the possibility of detecting large terrestrial planets in close orbits, while Kepler should be able to detect Earth-mass planets in Earth-like orbits by 2013 or earlier. All of which is promising, but we're still missing key elements of the puzzle. Take those transiting exoplanets COROT and Kepler track. We'll retrieve a wealth of data, but we probably won't be able to get the kind of spectroscopic information we'd like to see from a more advanced mission. Similarly, ground-based telescopes using adaptive optics, and future space missions like the James Webb Space Telescope should show us hot gas giants, but we'll be unlikely to see planets like our own Jupiter and Saturn, cooler worlds in more distant orbits. The solution? A team of NASA...

Although we're beginning to realize that brown dwarfs are widespread in the galaxy, we know surprisingly little about how they form. The question has an obvious impact on planetary formation models as well, but we won't get a good read on the answer until we've been able to study brown dwarfs and other very low-mass stars (VLMS) in multiple systems. Right now, relying largely on the Hubble Space Telescope and direct imaging via adaptive optics, we're unable to detect close binaries in such systems. That leaves radial velocity techniques to do the job. And indeed, a brown dwarf binary designated PPl 15 was found in the Pleiades in the late 90's with these methods. But the hope of landing a large number of close brown dwarf companions has faded. So far, despite ongoing work, we still have only three brown dwarf binaries confirmed through spectroscopy. And we're still asking planet-sized questions: Can a brown dwarf support planets at just a few AU distance? The assumption is yes, given...

Red giant stars have always held a fascination for me, doubtless spurred by an early reading of H.G. Wells' The Time Machine. Who can forget the time traveler's journey far into the future after his desperate escape from the Morlocks, millions of days passing in seconds as he flees: So I travelled, stopping ever and again, in great strides of a thousand years or more, drawn on by the mystery of the earth's fate, watching with a strange fascination the sun grow larger and duller in the westward sky, and the life of the old earth ebb away. At last, more than thirty million years hence, the huge red-hot dome of the sun had come to obscure nearly a tenth part of the darkling heavens. We can forgive Wells the mistaken timing -- thirty million years won't account for this! -- but still revel in the beauty of the concept. How it must have resonated at the end of the 19th Century. Today, red giants seem a bit more familiar as we've learned more about how they happen. And we do know that in...