Conclusions Summary of giant planet formation models

The smoothness of the distribution of masses of young M stars, free-floating brown dwarfs, and even free-floating objects somewhat below the deuterium-burning limit, argues strongly that these bodies formed in the same manner, i.e., via collapse, in some cases augmented by fragmentation. In contrast, the mass gap in nearby companions to Sun-like stars (the brown dwarf desert) is convincing evidence that (at least most of) the known giant planets formed in a different manner.

Various models for giant planet formation have been proposed. According to the prevailing core nucleated accretion model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary question regarding the core-accretion model is whether planets with small cores can accrete very massive gaseous envelopes within the lifetimes of gaseous protoplanetary disks.

The main alternative giant planet formation scenario is the disk instability model, in which gaseous planets form directly via gravitational instabilities within protoplanetary disks. Formation of giant planets via gas instability has never been demonstrated for realistic disk conditions. Moreover, this model has difficulty explaining the supersolar abundances of heavy elements in Jupiter and Saturn, and it does not explain the origin of planets like Uranus and Neptune. Nonetheless, it is possible that some giant planets form via disk instability.

Most models for extrasolar giant planets suggest that they formed as Jupiter and Saturn are believed to have (in nearly circular orbits, far enough from the star that ice could condense), and subsequently migrated to their current positions, although some models suggest in situ formation. Gas giant planet formation may (or may not) be common, because the gas within most of protoplanetary disks could be depleted before solid planetary cores grow large enough to gravitationally trap substantial quantities of gas. Additionally, an unknown fraction of giant planets migrate into their star and are consumed, or are ejected into interstellar space via perturbations of neighboring giant planets—so even if giant planet formation is common, these planets may be scarce.

This work was supported by NASA's Solar System Origins Program under RTOP 188-07-21-03.


Adachi, I., Hayashi, C., & Nakazawa, K. 1976 Prog. Theor. Phys. 56, 1756.

Adams, F. C. & Benz, W. 1992. In Complementary Approaches to Double and Multiple Star-

Research (eds. H. A. McAlister & W. I. Hartkopf). ASP Conf. Ser. 32, p. 170. ASP. Agnor, C. B., Canup, R. M., & Levison, H. F. 1999 Icarus 142, 219. Alencar, S. H. & Batalha, C. 2002 ApJ 571, 378.

Alibert, Y., Mousis, O., Mordasini, C., & Benz, W. 2005 ApJ 626, L57. Alonso, R., ET AL. 2004 ApJ 613, L153.

AndrE, P., Ward-Thompson, D. & Barsony, M. 2000. In Protostars and Planets IV (eds.

V. Mannings, S. Russel, & A. P. Boss). p. 59. Univ. Arizona Press. BARBIERI, M., ET AL. 2002 A&A 396, 219. Barnes, R. 2004. Ph.D. Thesis. University of Washington.

Barnes, R., Quinn, T. R., Lissauer, J. J., & Richardson, D. C. 2006 ApJ, in preparation. BATE, M. R., LUBOW, S. H., OGILVIE, G. I., & MILLER, K. A. 2003 MNRAS 341, 213. Bodenheimer, P., Burket, A., Klein, R., & Boss, A. P. 2000a. In Protostars and Planets IV (eds. V. Mannings, S. Russel, & A. P. Boss). p. 675. Univ. Arizona Press.

Bodenheimer, P., HuBICKYJ, O., & LlSSAUER, J. J. 2000b Icarus 143, 2. Boss, A. P. 2000 ApJ 536, L101.

Burrows, A., Sudarsky, D., & Hubbard, W. B. 2003 ApJ 594, 545.

CASSEN, P., Shu, F. H., & TEREBEY, S. 1985. In Protostars and Planets II (eds. D. C. Black

& M. S. Matthews). p. 448. Univ. Arizona Press. Chamberlain, T. C. 1905. In Carnegie Institution Year Book 3 for 1904. p. 195. Carnegie Inst.

of Washington D.C. Chambers, J. E. 2001 Icarus 152, 205.

Chambers, J. E., Quintana, E. V., Duncan, M. J., & Lissauer, J. J. 2002 AJ 123, 2884. Charbonneau, D., Brown, T. M., Latham, D. W., & Mayor, M. 2000 ApJ 529, L45. Chiang, E. & Goldreich, P. 1997 ApJ 490, 368.

Correia, A. C. M., Udry, S., Mayor, M., Laskar, J., Naef, D., Pepe, F., Queloz, D.,

& SANTOS, N. C. 2005 A&A, 440, 751. Cuzzi, J. N., Hogan, R. C., Paque, J. M., & Dobrovolskis, A. R. 2001 ApJ 546, 496. D'Angelo, G., Kley, W., & Henning, T. 2003 ApJ 586, 540. Duquennoy, A. & Mayor, M. 1991 A&A 248, 485.

Eggenberger, A., et AL. 2004. In Extrasolar Planets: Today and Tomorrow (eds. J. P.

Beaulieu, A. L. Etangs, & C. Terquem) ASP Conf. Ser. 321, p. 93. ASP. Fischer, D. A. & Valenti, J. 2005 ApJ 622, 1102. Ford, E. B., Havlickova, M., & Rasio, F. A. 2001 Icarus 150, 303. Forrest, W. J., et al. 2004 ApJ 154, 443. Gilliland, R. L., et AL. 2000 ApJ 545, L47. Goldreich, P. & Tremaine, S. 1980 ApJ 241, 425. Goldreich, P. & Tremaine, S. 2004 A&A 42, 549. Goldreich, P. & Ward, W. R. 1973 ApJ 183, 1051. Gonzalez, G. 2003 Revs. Mod. Phys. 75, 101.

Goodman, A. A., Benson, P. J., Fuller, G. A. & Myers, P. C. 1993 ApJ 406, 528. Goodman, J. & Pindor, B. 2000 Icarus 148, 537.

Greenberg, R., Wacker, J. F., Hartman, W. K. & Chapman, C. R. 1978 Icarus 35, 1. Hayashi, C., Nakazawa, I., & Adachi, I. 1977 Publ. Astron. Soc. Jpn. 29, 163. Hewins, R., Jones, R., & Scott, E. (Eds.) 1996. Chondrules and the Protoplanetary Disk. Cambridge Univ. Press.

Hollenbach, D., Yorke, H. W. & Johnstone, D. 2000. In Protostars and Planets IV (eds.

V. Mannings, S. S. Russell, & A. P. Boss). p. 401. Univ. Arizona Press. Holman, M. J., Touma, J., & Tremaine, S. 1997 Nature 386, 254.

Hubbard, W. B., Podolak, M., & Stevenson, D. J. 1995. In Neptune and Triton (ed. D. P.

Cruikshank). p. 109. Univ. Arizona Press. Hubickyj, O., Bodenheimer, P., & Lissauer, J. J. 2005 Icarus, 179, 415. Inaba, S., Wetherill, G. W., & Ikoma, M. 2003 Icarus 166, 46. Kokubo, E. & Ida, S. 1998 Icarus 131, 171. Kolvoord, R. A. & Greenberg, R. 1992 Icarus 98, 2. Kominami, J. & Ida, S. 2004 Icarus 167, 231. Kortenkamp, S. J. & Wetherill, G. W. 2000 Icarus 143, 60.

Lada, E. A., Strom, K. M., & Myers, P. C. 1993. In Protostars and Planets III (eds. E. H.

Levy & J. I. Lunine). p. 245. Univ. Arizona Press. Laskar, J. 2000 Phys. Rev. Lett. 84, 3240. Laughlin, G. & Adams, F. C. 1998 ApJ 508, L171. Levison, H. F., Lissauer, J. J., & Duncan, M. J. 1998 AJ 116, 1998. Lin, D. N. C. & papaloizou, J. 1979 MNRAS 186, 799.

Lin, D. N. C., Papaloizou, J. C. B., Terquem, C., Bryden, G., & Ida, S. 2000. In Protostars and Planets IV (eds. V. Manning, S. Russell, & A. P. Boss). p. 1111. Univ. Arizona Press. Lissauer, J. J. 1987 Icarus 69, 249. LISSAUER, J. J. 1993 ARA&A 31, 129. Lissauer, J. J. 1995 Icarus 114, 217. Lissauer, J. J. 2001 Nature 409, 23.

LlSSAUER, J. J. 2004. In Extrasolar Planets: Today and Tomorrow (eds. J. P. Beaulieu, A. L. Etangs, & C. Terquem). ASP Conf. 321, p. 271. ASP.

Lissauer, J. J., Quintana, E. V., Chambers, J. E., Duncan, M. J., & Adams, F. C. 2004. In Gravitational Collapse: From Massive Stars to Planets (eds. G. García-Segura, G. Tenorio-Tagle, J. Franco, & H. W. Yorke). Rev. Mex. Astron. Astrof. 22, 99.

LIVIO, M. & PRINGLE, J. E. 2003 MNRAS 346, L42.

Lyne, A. G., Biggs, J. D., Brinklow, A., McKenna, J., & Ashworth, M. 1988 Nature 332, 45.

Mac Low, M. & Klessen, R. 2004 Revs. Mod. Phys. 76, 125.

Marcy, G. W., Butler, R. P., Fischer, D. A., & Vogt, S. S. 2004. In Extrasolar Planets: Today and Tomorrow (eds. J. P. Beaulieu, A. L. Etangs, & C. Terquem). ASP Conf. 321, p. 3. ASP.

Marcy, G. W., Butler, R. P., Fischer, D. A., Vogt, S. S., Lissauer, J. J., & Rivera, E. J. 2001 ApJ 556, 296.

Marcy, G. W., et al. 2005 Prog. Theor. Phys. Supp. 158, 24.

Masset, F. S. & Papaloizou, J. C. B. 2003 ApJ 588, 494.

Mathieu, R. D., Ghez, A. M., Jensen, E. L. N., & Simon, M. 2000. In Protostars and Planets IV (eds. V. Mannings, S. Russell, & A. P. Boss). p. 703. Univ. Arizona Press.

Mayer, L., Quinn, T., Wadsley, J., & Stadel, J. 2002 Science 298, 1756.

McCaughrean, M. J., Stepelfeldt, K. R., & Close, L. M. 2000. In Protostars and Planets IV (eds. V. Mannings, S. Russell. & A. P. Boss). p. 485. Univ. Arizona Press.

NAKANO, T. 1987 MNRAS 224, 107.

Ohtsuki, K., Stewart, G. R., & Ida, S. 2002 Icarus 155, 436.

Pollack, J. B., Hubickyj, O., Bodenheimer, P., Lissauer, J. J., Podolak, M., & Green-ZWEIG, Y. 1996 Icarus 124, 62.

Quintana, E. V. 2004. Ph.D. Thesis, University of Michigan, Ann Arbor.

Quintana, E. V. & Lissauer, J. J. 2006 Icarus 185, 1.

Quintana, E. V., Lissauer, J. J., Chambers, J. E., & Duncan, M. J. 2002 ApJ 576, 982.

Safronov, V. 1969. Evolution of the protoplanetary cloud and formation of the Earth and, planets. Nauka Press; 1972 English translation: NASA TTF-677.

Santos, N. C., Israelian, G., Mayor, M., Rebolo, R., & Udry, S. 2003 A&A 398, 363.

Showalter, M. R. 1991 Nature 351, 709.

Sigurdsson, S. 1993 ApJ 415, L36.

Sigurdsson, S., Richer, H. B., Hansen, B. M., Stairs, I., & Thorsett, S. E. 2003 Science 301, 193.

Strom, S. E., Edwards, S., & Skrutskie, M. F. 1993. In Protostars and Planets III (eds. E. H. Levy & J. I. Lunine). p. 837. Univ. Arizona Press.

Thommes, E. W., Duncan, M. J., & Levison, H. F. 2003 Icarus 161, 431.

Thommes, E. W. & Lissauer, J. J. 2005. In Astrophysics of Life (eds. M. Livio, I. N. Reid, & W. B. Sparks). p. 41. Cambridge Univ. Press.

Tsiganis, K., Gomes, R., Morbidelli, A., & Levison, H. F. 2005 Nature 435, 459.

Udry, S., Mayor, M., Naef, D., Pepe, F., Queloz, D., Santos, N., & Burnet, M. 2002 A&A 390, 267.

Ward, W. R. 2000. In Origin of the Earth and Moon (eds. R. M. Canup & K. Righter). p. 75. Univ. Arizona Press.

Ward, W. R. & Hahn, J. 2000. In Protostars and Planets IV (eds. V. Manning, S. Russell, & A. P. Boss) p. 1135. Univ. Arizona Press.

Weidenschilling, S. J. 1977 MNRAS 180, 57.

Weidenschilling, S. J. 2005 Space Sci. Rev. 116, 53.

Weidenschilling, S. J. & CUZZI, J. N. 1993. In Protostars and Planets III (eds. E. H. Levy & J. I. Lunine) p. 1031. Univ. Arizona Press.

Weidenschilling, S. J. & Marzari, F. 1996 Nature 384, 619. Wetherill, G. W. 1990 Ann. Rev. Earth Planet. Sci. 18, 205. Wetherill, G. W. 1994 Astrophys. Space Sci. 212, 23. Wetherill, G. W. & Stewart, G. R. 1989 Icarus 77, 330.

Whitmere, D. P., Matese, J. J., Criswell, L., & Mikkola, S. 1998 Icarus 132, 196. Wuchterl, G., Guillot, T., & Lissauer, J. J. 2000. In Protostars and Planets IV (eds.

V. Mannings, S. Russell, & A. P. Boss). p. 1081. Univ. Arizona Press. Wuchterl, G. & Tscharnuter, W. M. 2003 A&A 398, 1081. Youdin, A. N. & Shu, F. H. 2002 ApJ 580, 494. Young, R. E. 2003 New Astron. Revs. 47, 1.

Zapatero Osorio, M. R., Béjar, V. J. S., Martin, E. L., Rebolo, R., Barrado, Y., NavascuEs, D., Bailer-Jones, C. A., & Mundt, R. 2000 Science 290, 103.

Was this article helpful?

0 0

Post a comment