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...

In a world dominated by short-term thinking, we tend to be driven by media cycles. That makes the coverage of science, among other subjects, problematic. Science operates through the analysis of detail as various minds subject a problem to hypotheses that can be tested experimentally. In other words, good science often takes time, which is why situations like the Gliese 581c story can be so frustrating. Announce a habitable planet around another star and the media love you. Spend months and (if needed) years subjecting the habitability question to analysis and you're not on the public radar. Many scientists have come to question whether Gliese 581c is remotely habitable; some even argue for habitability for the next planet out, Gliese 581d. We're still trying to weigh the data, and such deliberate processes aren't the sort of thing to replace the latest Hollywood starlet scandals on CNN. The good scientist ignores media vagaries and proceeds with the painstaking details. The hunt for...

HD 98800 is an unusual system indeed. About 150 light years away in the constellation TW Hydrae, the four stars that make it up consist of two binary pairs that circle each other. The distance between the two pairs is about 50 AU, which is roughly the average distance between Pluto and the Sun. Imagine having, instead of icy Kuiper Belt objects, a binary star system at the edge of our Solar System. Note: The reference above should probably be to the TW Hydrae association, not 'constellation,' as noted in the comments below. Image: This artist concept depicts the quadruple-star system HD 98800. The system is approximately 10 million years old, and is located 150 light-years away in the constellation TW Hydrae. HD 98800 contains four stars, which are paired off into doublets, or binaries. The stars in the binary pairs orbit around each other, and the two pairs also circle each other like choreographed ballerinas. Credit: NASA/JPL-Caltech/T. Pyle (SSC-Caltech). The idea of planet...