20111109

The Extrasolar Planets Encyclopaedia http://exoplanet.euCatalog of Exoplanets http://www.planetary.org/exoplanets/Exoplanet for iPhone/iPod touch/iPad

巨大氷惑星形成 ©Newton Press

15 12 9 6 3 00.0001 0.001 0.01 0.1 1

random velocity of planetesimals is pumped up as high asthe escape velocity of protoplanets. This high random veloc- On the otity makes the accretion process slow and inefficient and thus in circular oTgrow longer. This accretion inefficiency is a severe problem HD 192263 with Æ1 e1 for in situ f Mdisk T cont <Tdisk Tgrow<Tdisk case. It is di slingshot m circular orb the magneti may be wea disks may b Terrestria Jovian plan planetary a key process systems. We confir holds in a Æsolid ¼ Æ1 ð ¼ 1=2; 3= tions. We d Fig. 13.—Schematic illustration of the diversity of planetary systems systems depagainst the initial disk mass for < 2. The left large circles stand for centralstars. The double circles (cores with envelopes) are Jovian planets, and the disk profileothers are terrestrial and Uranian planets. [See the electronic edition of the growth time

earing continues through scattering. After orbital time scales and high inclinations. three categories: (i) hot Earth analogs interior to 00 million years the inner disk is composed Two of the four simulations from Fig. 2 the giant planet; (ii) Bnormal[ terrestrial planets the collection of planetesimals at 0.06 AU, a contain a 90.3 M] planet on a low-eccentricity between the giant planet and 2.5 AU; and (iii) M] planet at 0.12 AU, the hot Jupiter at 0.21 orbit in the habitable zone, where the temper- outer planets beyond 2.5 AU, whose accretion U, and a 3 M] planet at 0.91 AU. Previous ature is adequate for water to exist as liquid on has not completed by the end of the simulation. sults have shown that these planets are likely a planet_s surface (23). We adopt 0.3 M] as a Properties of simulated planets are segregated be stable for billion-year time scales (15). lower limit for habitability, including long-term (Table 1): hot Earths have very low eccentric-Many bodies remain in the outer disk, and ac- climate stabilization via plate tectonics (24). ities and inclinations and high masses because they accrete on the migration time scale (105 niscent of the recently discovered, close-in 7.5 M] years), so there is a large amount of damping planet around GJ 876 (25), whose formation is during their formation. These planets are remi- also attributed to migrating resonances (26). g. 1. Snapshots in time of the evolution of one simulation. Each panel of each body’s inclination on the y-axis scale. The color of each dot ots the orbital eccentricity versus semimajor axis for each surviving body. corresponds to its water content (as per the color bar), and the dark inner he size of each body is proportional to its physical size (except for the dot represents the relative size of its iron core. For scale, the Earth’s water ant planet, shown in black). The vertical ‘‘error bars’’ represent the sine content is roughly 10j3 (28).

Weidenschilling &,Marzari (1996),,Lin,& (t >~ 1My) , . e . finala .a .GM * GM * GM * GM * GM * a1 a2 a3 a a

20111109

by noinoi79528 on Nov 09, 2011

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 85

Statistics

20111109 — Presentation Transcript