14-04 Extrasolar Planets

Is the solar system formation model described in the previous section a correct one?
 

Extrasolar planets are too dim and too close to their parent stars to observe directly.




The method of determining masses in a single-line spectroscopic binary was exploited to find the first extrasolar planet orbiting 51 Pegasi in 1995.



The mass function:
m₂³sin³q  /  (m₁+m₂)²  =  v₁³P  /  (2pG)
 

The number of detected extrasolar planets is increasing rapidly!



(For updated information, check Exoplanet Data Explorer.)
 

The 4 methods to detect exoplanets:
radial velocity, transit, microlensing, and direct imaging

But, challenges to the model of planet formation: they all have large masses and small orbital radii; many of them have large eccentricity.
 

Extrasolar planets vs brown dwarfs
red dwarfs (0.08 -- 0.8 solar mass)
brown dwarfs (0.013 -- 0.08 solar mass)

The Kepler mission uses the transit method. Earth-like exoplanet candidates have been found...