Monday, June 16, 2008

Huge "harvest" of small exoplanets by HARPS detailled; includes 'super-earth' trio

Vague reports had already come out at another conference, but today the details have been released about some 45 exoplanet candidates found with the special HARPS spectrograph at the ESO 3.6-meter telescope: they all have a mass below 30 Earth masses and an orbital period shorter than 50 days. Among the discoveries with the radial velocity method is a star having three small planets with 4.2, 6.7 and 9.4 times the mass of the Earth that orbit the star HD 40307 with periods of 4.3, 9.6 and 20.4 days, respectively. "Does every single star harbour planets and, if yes, how many?" planet hunter Michel Mayor from Geneva Observatory now wonders - exactly what he already told an audience in Bonn ½ year ago. Even the most classical of exoplanet hunting techniques, it seems, is now approaching a detection limit of an Earth mass or two.

In other news shatter cones - the largest known - from an ancient impact have been found next to a busy road, though the impact crater is long gone. • A very long paper discusses the long-term light curve of comet Encke. • Io and its shadow in front of/on Jupiter's disk yesterday, also another fine color Jupiter from mid-June. • Olga is just the latest asteroid one dedicated observer saw covering a star. • The light curve of Nova Oph is pretty variable. • Many NLC observations have already been made this year, including the first bright ones and a sighting from Germany.

• Yet another Namibian astronomy report to whet one's appetite for going there once again... • With Discovery back home, the next shuttle will fly to Hubble, if repairs on Discovery's launch pad succedd in time, as is expected. One may also dream about a huge liquid mirror telescope on the Moon in the more distant future. • And finally, in case you missed the link appearing a bit later in a link from here: These are the pics of Venus 3.7' from the solar limb!

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