The planetary systems so far discovered around other stars have generally been dominated by huge, gas giant worlds, many with so-called 'hot Jupiters' that orbit extremely close to their parent star. And that makes sense, given that a major method used for detecting exoplanets relies upon the star's 'wobble' as it is influenced by such high-mass objects. We're not yet at the point where Earth-sized planets can be found, although we've reduced the detection size down to Neptune-class objects, with better things to come. But don't assume that even the systems discovered so far are without terrestrial planets. As many as half of them may harbor habitable worlds, according to work by Barrie Jones, Nick Sleep, and David Underwood at the Open University in Milton Keynes (UK), which was presented today at the Royal Astronomical Society National Astronomy Meeting in Birmingham. The team used computer models to analyze the gravitational effects of known exoplanets on other, undiscovered...

Sky & Telescope is reporting that the purported planet around GQ Lupi may not be a planet but a brown dwarf. The magazine evidently draws this conclusion from a study of the paper by Ralph Neuhaeuser and colleagues that is to run in an upcoming issue of Astronomy & Astrophysics. "The newly released paper by Neuhauser and his colleagues suggests that the the object in question could be as much as 42 Jupiter masses. Brown dwarfs are, by definition, between 13 and 74 Jupiter masses," the magazine reports. Meanwhile, data on the possible GQ Lupi planet can be found at the Extrasolar Planets Encyclopedia. The preprint of the Neuhaeuser paper, "Evidence for a co-moving sub-stellar companion of GQ Lup," is available here. A key excerpt from the paper: The most critical point in the mass determination of the companion (candidates) of GQ Lup and 2M1207 are the models, which may be off by an unknown factor for low ages (few Myrs); they need to be calibrated, before the mass of such companions...

Space.com is reporting that a European team led by Ralph Neuhaeuser of the Astrophysical Institute & University Observatory has obtained a photograph of an extrasolar planet around GQ Lupi, a young star about 400 light years from Earth. The image shows a faint object the team believes to orbit some 100 AU from its parent star, an apparently young and hot planet. From the article: The planet is about 3,140 degrees Fahrenheit (2000 Kelvin) -- not the sort of place that would be expected to support life. Neuhaeuser's team has also detected water in the planet's atmosphere. The world is expected to be gaseous, like Jupiter. It is about twice the diameter of Jupiter. The mass estimate -- one to two times that of Jupiter -- is "somewhat uncertain," Neuhaeuser said. The planet is three times farther from GQ Lupi than Neptune is from our Sun. "We should expect that the planet orbits around the star, but at its large separation one orbital period [a year] is roughly 1,200 years, so that...