"Transiting Planets" Day 3

Tristan

M-R relations from Zapolsky & Salpeter 1969

Showed the figure of Bouchy, Monte-Carlo-simulated M-R relation sample.

Anomalously large planets:
TrES-4 b.............not too bloated. A reasonable model can be creatd.
CoRoT-2 b..........The star is variable. Planetary radius may be overestimated?

Massive Planet:
HAT-P-2 b........ 600 Mearth ice core at the center? (Baraffe)

Large solid mass:
HD149026, XO-2, OGLE-TR-56, HAT-P-2, etc.
Giant impacts and core merger can be a possible explanation for massive cores.
Alternatively, evaporation of close-in planets, perhaps incorporating tidal effects,
is also possible.

Sara Seager
Mercury's core is 60% of the mass.

Two competing theories for Fe:
Fe is expected to sink toward the core.
At the same time, it can oxidize and get incorporated to the mantle. For this scenario, water content in the mantle is key to the Fe oxidization, and the amount of water depends on the radial mixing in the protoplanetary disk.

So, in the core, there should be a simple inverse relation for Fe and H2O. A coreless Earth should have Fe-rich mantle.

Willie Benz
Monte Carlo simulation of planet formation and migration (Pollack 1996)

Yanqin
The 3-day pile up in the orbital period histogram should be a natural outcome of
Kozai migration.

Deming

Spectroscopic observations:
HD209458.............Grillmair 2007, Richardson 2007, Swain 2008
IRAC broad-band spectrum requires temperature inversion in the atmosphere.
(and flatness of the water absorption)

GJ 436 b...................secondary eclipse observation
Teq = 640K Tobs = 712K
Spitzer G05, multiple-eclipse, around-the-orbit observations
EPOXI is currently observing multiple transits from space.

Eric Agol
Precise transit-timing and transit depth variations. For the TTV due to a non-resonant, eccentric perturber, dt = P1 e2 m2/m0 P1 / P2. It is 33 sec for WASP-9, and 0.3 sec for CoRoT-Exo-1.

Jackson
Tidal circularization timescale has been historically underestimated.
Tidal heating rate is not constant during migration (isn't that obvious?)
So, external perturber may not be necessary to explain eccentric close-in planets (e.g., GJ 436 b).
Also, past tidal heating bloats up planets because tidal heating takes ~Gyr to get out (!! reasoning unclear).

Laughlin
HD80606 transit campain (pericenter distance is 6.5 Rstar). Pseudo-spin-orbit synchronization is expected.