Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?
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Transcript of Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?
Planetary characteristics? Some trend in M versus R (bias?), butbeyond 0.05-0.1 AU, little preference for low eccentricities:
Butler, R.P. et al. 2006, ApJ, 646, 505
Even with incompleteness, strong preference for ~Jovian mass:
Butler, R.P. et al. 2006, ApJ, 646, 505
Stars are different, turnover at low mass!
“The brown dwarf desert”?
Does this tell usthat stars and planets formdifferently?
Orion IMF
Is there an eccentricity preference w/mass? Not really, part II…
Butler, R.P. et al. 2006, ApJ, 646, 505
?
Another clue as to formation: Planet formation efficiency correlates strongly with metallicity!
Fischer, D.A. & Valenti, J. 2005, ApJ, 622, 1102
GJ 876 orbitsevolve with time (expected w/mutual perturbations)!
What about other systems?
Rivera, E.J. et al. 2005, (see class web site)
What we know:- ~1% of solar-type stars have Hot Jupiters
-~7% of solar-type stars have >Mj planets in the “terrestrial planet” region. Extrapolation of currentincompeteness suggests ~12% w/planets @ <20 AU.
- multiple planetary systems are ~common
- planetary resonances are ~common
What can explain these properties?
Disk-star- and protoplanet interactions lead to migration while the gas is present. Core- accretion?
Theory
1 AU at 140 pc subtends 0.’’007.
Jupiter (5 AU):V_doppler = 13 m/sV_orbit = 13 km/sSimulation G. Bryden, JPL
Thus, need to study objects in this phase…
Core-accretion models can now be compared to observations:
Planetsversusmetallicity:
Data
Observedin opencircles.
Ida, S. & Lin, D. 2004, ApJ, 616, 567