We're back, we're tanned, we're rested, we're ready: 4th day, session 7,
in which Kepler annouces the discovery of the second circumbinary exoplanet...
Ok, we're not going yet, but the press release came out at noon:
- 41d orbital period binary star, KV primary (bit less massive than the Sun).
Secondary is an M star.
Sub-solar metallicity, low eccentricity stellar orbit (e1=0.15)
about 60 pc away.
Planet is transiting, natch, 0.33 MJM
in a 229d near circular circumbinary orbit.
This is the second circumbinary planet discovered, after 1620-26b and the first orbiting two main sequence stars.
This is the second circumbinary planet discovered, after 1620-26b
So what about HW Virginis, DP Leonis, HU Aquarii, NN Serpentis, and UZ Fornacis?
Carter mentioned those as unconfirmed.
Didn't mention 1620-26.
Interesting, was any particular reason given why these candidates should be regarded as less reliable than, say, RV planet detections?
On the other hand B1620-26 is clearly irrelevant and not worth considering because it is a pulsar planet (same reason as why various RV planet people can keep claiming that they've found the "smallest known exoplanet" when their super-Earths exceed the mass of the innermost PSR B1257+12 planet by several orders of magnitude...)
Concern that the ETV might be due to stellar companions or other effects - he rattled a couple off, don't know if they're plausible alternatives quantitatively
I think next IAU conference may have the "planets are only around main sequence stars" issue surface, in conjunction with the refighting of the great "what is a planet" battle.
IAU already has a "an exoplanet is what we would call a planet in our solar system, but around another star" clause.
I almost wanna see astronomers explain to the public why the Earth will no longer be a planet when the Sun becomes a white dwarf?
And what about giants? Sub-giants?
We'll need lots of popcorn.