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Lightest exoplanet discovered April 22, 2009

Posted by Sarah in new astronomy, science.
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ESO yesterday reported the discovery of the lightest exoplanet yet. Gliese 581e, the fourth in a family of exolanets around Gliese 581, is just twice as massive as the Earth, which means it could well be rocky rather than gassy like Jupiter or Saturn. The discovery was made by a team of Swiss an French astronomers led by Michel Mayor of Geneva Observatory, who discovered of the first ever exoplanet in 1995, using ESO’s 3.6m telescope at La Silla, Chile.

But Mayor and his team added a cherry to ESO’s cake. Further study of the orbit of Gliese 581d, one of the new planet’s known siblings, has shown that the planet lies well within the host star’s so-called Habitable Zone, where the existence of liquid water is thought to be possible (though that doesn’t mean that it does!).

Nice work!

Image credit: M. House, F. Kamphues (top)

Kepler sees the light April 20, 2009

Posted by Sarah in science, space.
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First light images from NASA’s Kepler space telescope were released last week following the satellite’s sucecssful launch on March 7. The picture shown here shows an (inversted) image of the starfield Kepler will be studying over the course of its exoplanet-finding mission, in the Cygnus-Lyra region of the Galaxy. It may not look like much, but for the Kepler team it’s pretty special to see that their satellite is alive and well, and performing as it should. Congrats!

Go here for the full set of first light images.

Image credit: NASA/Ames/JPL-Caltech

Countdown to Kepler March 3, 2009

Posted by Sarah in science.
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Astronomers’ eyes are on NASA this week as the agency aims to launch its mission for tracking down Earth-like exoplanets on Friday night (early Saturday morning if you’re in Europe). Over its three-year lifetime, Kepler will observe over 100,000 stars in a small part of the sky, over and over again to spot the tiny dips in brightness caused by a planet casting its shadow onto the star as it passes in front of it. Together with its European cousin CoRoT, which has been in orbit for a while already, Kepler is likely to increase our tally of known exoplanets by a factor of many. There’s been a ton of great media coverage about Kepler already so I’ll round up a few nice links here. And there’ll be much more to follow!

From NASA itself: the mission homepage, launch schedule. A live launch blog will appear here 2 hours before launch.

Follow Kepler on Twitter.

The New York Times have a great feature here.

Seth Shostak of the SETI Institute gives his perspective on Discovery Space. Discovery Space have a little Kepler-themed area even, here.

A BBC story on British industrial involvement in Kepler.

[Update 04/03]

Director of Hubble news Ray Villard (Cosmic Ray) gives his perspective.

A news story in Nature.

Image credit: Ball Aerospace

The benefit of hindsight February 26, 2009

Posted by Sarah in science.
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Left: The image of the HR8799 planetary system from data taken with the Keck telescope. Right: the 1998 Hubble data (credit: NRC) (a) original Hubble image, (b) with "traditional" speckle subtraction method, (c-d) 2 images reprocessed showing the planet above the noise (credit: Lafrenière et al., 2009).

An interesting paper turned up on astro-ph last week. Remember HR8799, the star with a whole family of exoplanets imaged directly last year? A Canadian-American team of scientists went back through the archive and re-analysed data taken with the Hubble Space Telescope in 1998. And lo and behold, using new analysis techniques they managed to tease the outermost of HR8799’s planets out of the noise. Very cool. After all, 1998 was only three years after the first ever detection of an exoplanet! Obtaining a direct image of one really was just a glint in our starry eyes back then.


Super-earth confirmed, first of many? February 3, 2009

Posted by Sarah in science.
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Today with much to-do and under heavy embargoes, scientists have announced the discovery of an extrasolar planet with a mass diameter of just 1.7 times that of the Earth. That’s very very small. With a mass of It whizzes around its host star, Exo-7, in around 20 hours and with a temperature of over 1,000 degrees, is incredibly hot. Using data from the satellite CoRoT (Convection Rotation and planetray Transits), the German-led French-led team of scientists detected the minute dip in the light coming from the host star from the planet passing in front of it. The discovery was confirmed with observations at a number of ground-based observatories, including VLT, the Canada-France-Hawaii telescope, McDonald Observatory.

In case you hadn’t noticed: exoplanet news is coming hard and fast. Every year since 1995, when Mayor & Queloz reported the discovery of 51 Peg b, has seen a number of “major breakthroughs” (see here, here, and many more) in the detection and characterisation of planets around other stars in our Galaxy.  Scientists have pushed the boundaries of our knowledge to a massive extent, and the rapid progress is just fantastic. But brace yourself for more.