50 more exoplanets found (and many more candidates)!

A lot of exoplanet news today, as promised. At least 50 new confirmed exoplanets were announced today by the HARPS astronomers, including 16 which are “super-Earth” sized (up to about 2-3 times the diameter of Earth), one of which (HD 85512 b) orbits at the edge of the habitable zone of its star and is about 3.6 times the mass of the Earth. That is the single largest group announced at one time. This is going by the information in the official press release linked above, but according to notes taken during the Extreme Solar Systems II conference at Jackson Lake, Wyoming which is going on now, the HARPS exoplanet count is 55 with 19 of super-Earth size. The data also suggests that about 40% of sun-like stars have at least one planet less massive than Saturn and the majority of smaller mass planets are in solar systems with multiple planets.

Artist’s impression of super-Earth planet HD 85512 b. Credit: ESO/M. Kornmesser

This brings the total current count of confirmed exoplanets to at least 645 according to The Extrasolar Planets Encyclopaedia, and possibly 648 or more, according to some other sources. It’s starting to get harder to keep up, and this can all be a bit confusing (in a good way of course)…

But that is not all… at the same conference, it was announced today that the number of candidate exoplanets found by Kepler so far has risen to 1,781, with 27 of those confirmed to date! 123 of those have an estimated radius of less than 1.25 times that of Earth, 121 are within the habitable zones of their stars and about a quarter of the candidates are super-Earth sized. The next major data release will be on September 23.

Update (9/13/11): Yesterday the exoplanet count was 645, but now today it’s 677! More results announced today at the ESS2 conference, this time from WASP.

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