Results from the Wide Angle Search for Planets (SuperWASP) could hardly be better. In the last six months, astronomers using wide-field cameras in the Canary Islands and South Africa, working in conjunction with a battery of telescopes around the world, have identified ten new planets around other stars. The findings were announced yesterday at the Royal Astronomical Society’s national meeting in Belfast. We’re dealing with planetary transits here, planets moving across the face of their star as seen from Earth. 46 transiting worlds are known, of which SuperWASP has now found a solid fifteen.
Skymaps, coordinates and background information on all the SuperWASP planets can be found here. You’ll want to concentrate on WASP-6b through 15-b for the new ones, which include ‘hot Jupiters’ like WASP-12b (orbiting its primary, a G-class star 870 light years from Earth, in just over a day) and WASP-15b, one-half the mass of Jupiter, orbiting an F5 star a thousand light years away. The largest planet found was fully eight times the mass of Jupiter, again orbiting an F5 star in a scant 2.24 days.
Image: A schematic of the new discoveries. Click the diagram to get an enlarged image with further data. Credit: SuperWASP.
The robotic SuperWASP cameras sweep huge areas of the sky each night, offering astronomers data on millions of stars. Information on promising candidates is distributed to observatories ranging from the Nordic Optical Telescope on La Palma to the Swiss Euler Telescope in Chile and the Observatoire de Haute Provence in southern France. The Geneva Extrasolar Planet Search group then confirms potential planetary discovery through spectrographic analysis. The beauty of transits is that information about the size and mass of each planet can be deduced from the observations. With Kepler upcoming and COROT continuing its doughty work, the pace of transit discovery should only increase.
Addendum: Greg Laughlin (UC-SC) notes his annoyance with the SuperWASP announcement, particularly the lack of coordinates for the new planets and the inconsistency of some of the data on the relevant Web site. WASP-6b is reported, for example, to have a radius fifty percent that of Jupiter, and a mass of 1.3 Jovian masses. Says Laughlin on his systemic site:
That’s nuts! If the planet is so small, why is the transit so deep? And a 2200 K surface temperature for a 3.36d planet orbiting a G8 dwarf? Strange. Perhaps the radius and mass have been reversed? In addition, there are weird inconsistencies between the numbers quoted in the media diagram and in the tables. For example, the diagram pegs WASP-7 at 0.67 Jovian masses, whereas the table lists it at 0.86 Jovian masses. WASP-10 has a period of 5.44 days in the table and 3.093 days in the summary diagram. Putting out a press release without the support a refereed paper is never a very good idea, even when there’s a danger that another team will steal your thunder with an even larger batch of planets.