Kepler 10-b, announced at the Annual meeting of the American Astronomical Society today, has a mass of 4.6 Earth masses and a radius of 1.4 Earth radii. Density of 8.8
Kepler Mission website – 700 more to go.
20 hour orbital period around an old, slightly metal poor ( Z ~ -0.15) G dwarf.
500 light years away.
Paper is Batalha et al (ApJ in press) – expect it will be on arXiv tonight.
Lightcurve ought to be interesting, will really tell us how deep Kepler is going to go.
11th magnitude host star, quoted at 12 +/- 4 Gyr age – sincerely hope the “+” is spurious based on assumption of symmetric errors – if it really is 16 Gyr then the star is rather more interesting then the planet… 😉
So really 8-12 Gyr old, and probably, given its position and metallicity, more like 8-9 Gyr old.
Good astroseismology on the star, that will make an interesting paper in its own right.
Here is the light curve (click to embiggen).
Yup, they ought to be able to go shallower.
One earth radius might be in reach… interesting.
Maybe a second planet, 20 Earth masses, or less, candidate label Kepler 10c, in an outer orbit at 45d orbital period and planetary radius of about 10,000 km.