Still working on an There have been several interesting items at the Extreme Solar Systems conference here in Santorini
I think the surprise announcement from the California exoplanets groups that they have a genuine Jupiter analog - a Jupiter mass planet in a long period, low eccentricity orbit, very similar to our own Jovian - is a key, and long awaited, discover.
The Swiss group has 12 new planets, several with long ( > 2000 day) orbital period and apparent low eccentricities.
They are seeing a deficit of planets with 10-100d orbital periods, which is interesting, things are piling up at multi-year periods as the searches go on for long enough to have senstivity out there.
They cautiously extrapolate to ~ 25% of Sun-like stars having planets with Jupiter mass or above and with orbital radii of 3-20 AU. If you extrapolate the curve from the recent data, the percentage could be significantly higher.
There is a hint of a peak in the eccentricity distribution at ~ 300d period (this is my interpretation of the collected data, not theirs) - ie the recent long period planets are trending to lower eccentricties, but this could be selection bias.
They have another low metallicity star, HD171028, with a planet (~ 2 jupiter masses).
The newly discovered short period Neptune mass planets are not showing any trends with host star metallicity, unlike the short period jovian mass planets, which show a strong trend.
Mayor notes that there is some hint of a shortage of (short period) intermediate mass planets, with 50-100 Earth masses - this is broadly consistent with core accretion formation theories for giant planets, where if you start accreting gas and getting much above 10 Earth masses, the mass builds up very quickly to Saturn/Jupiter masses.
Still, might expect more intermediate mass long period planets around lower mass stars, where, presumably, disk masses are generally lower, and there may just not be enough gas to accrete for high mass cores to reach jovian masses (my interpretation).
There are now 13 known Neptune mass planets, with more candidates in the pipeline (30-50 candidates just in the HARPS data set)!
HARPS is now reaching radial velocity measurement of better than 1 m/sec and may reach 0.1 m/sec for the brightest stars.
They are seeing a lot of stellar "jitter" at the m/sec level - some of which is intrinsic, but some of which is actually unresolved signal from multiple or undersampled low mass planets!
They are also seeing a lot of low mass planets around stars known to have high mass stars. This is selection biased, since stars with known planets are followed up more intensely than blind searches around stars with no known planets yet.
Everything points to lots of planets of all kinds everywhere.
Next generation spectrographs (ESPRESSO) should operate at 10cm/sec routinely on 8-10 m class telescopes (ie VLT) and reach 1 cm/sec on next generation large telescope like ELT.
Hm, that is the first half of the first morning of the meeting...
