Four Sub-Saturns with Dissimilar Densities: Windows into Planetary Cores and Envelopes

被引：71

作者：

Petigura, Erik A. ^{[1
]}

Sinukoff, Evan ^{[2
]}

Lopez, Eric D. ^{[3
]}

Crossfield, Ian J. M. ^{[4
]}

Howard, Andrew W. ^{[1
]}

Brewer, John M. ^{[5
]}

Fulton, Benjamin J. ^{[1
,2
]}

Isaacson, Howard T. ^{[6
]}

Ciardi, David R. ^{[7
]}

Howell, Steve B. ^{[8
]}

Everett, Mark E. ^{[9
]}

Horch, Elliott P. ^{[10
]}

Hirsch, Lea A. ^{[6
]}

Weiss, Lauren M. ^{[11
]}

Schlieder, Joshua E. ^{[7
]}

机构：

[1] CALTECH, 1200 E Calif Blvd, Pasadena, CA 91125 USA

[2] Univ Hawaii Manoa, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA

[3] Univ Edinburgh, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland

[4] Univ Calif Santa Cruz, 1156 High St, Santa Cruz, CA 95064 USA

[5] Yale Univ, New Haven, CT 06520 USA

[6] Univ Calif Berkeley, Berkeley, CA 94720 USA

[7] CALTECH, IPAC NExScI, 770 South Wilson Ave, Pasadena, CA 91125 USA

[8] NASA, Ames Res Ctr, Mail Stop 204-14, Moffett Field, CA 94035 USA

[9] Natl Opt Astron Observ, 950 North Cherry Ave, Tucson, AZ 85719 USA

[10] Southern Connecticut State Univ, Dept Phys, 501 Crescent St, New Haven, CT 06515 USA

[11] Univ Montreal, Inst Rech Exoplanetes, Montreal, PQ, Canada

来源：

ASTRONOMICAL JOURNAL | 2017年 / 153卷 / 04期

关键词：

planets and satellites: composition; planets and satellites: detection; planets and satellites: dynamical evolution and stability; planets and satellites: formation; planets and satellites: gaseous planets; planets and satellites: interiors; MASS PLANET; URANIAN SATELLITES; TIDAL EVOLUTION; KEPLER PLANETS; STARS; K2; PHOTOMETRY; TRANSIT; HOT; EXOPLANETS;

D O I：

10.3847/1538-3881/aa5ea5

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present results from a Keck/HIRES radial velocity campaign to study four sub-Saturn-sized planets, K2-27b, K2-32b, K2-39b, and K2-108b, with the goal of understanding their masses, orbits, and heavy-element enrichment. The planets have similar sizes (R-P = 4.5-5.5 R circle plus), but have dissimilar masses (M-P = 16-60 M circle plus), implying a diversity in their core and envelope masses. K2-32b is the least massive (M-P = 16.5. 2.7M circle plus) and orbits in close proximity to two sub-Neptunes near a 3: 2: 1 period commensurability. K2-27b and K2-39b are significantly more massive at M-P = 30.9. 4.6M circle plus and M-P= 39.8. 4.4M circle plus, respectively, and show no signs of additional planets. K2-108b is the most massive at M-P= 59.4. 4.4M circle plus, implying a large reservoir of heavy elements of about approximate to 50 M circle plus. Sub-Saturns as a population have a large diversity in planet mass at a given size. They exhibit remarkably little correlation between mass and size; sub-Saturns range from approximate to 6-60 M circle plus, regardless of size. We find a strong correlation between planet mass and host star metallicity, suggesting that metal-rich disks form more massive planet cores. The most massive sub-Saturns tend to lack detected companions and have moderately eccentric orbits, perhaps as a result of a previous epoch of dynamical instability. Finally, we observe only a weak correlation between the planet envelope fraction and present-day equilibrium temperature, suggesting that photo-evaporation does not play a dominant role in determining the amount of gas sub-Saturns accrete from their protoplanetary disks.

引用

页数：19

共 87 条

[1] Precise time series photometry for the Kepler-2.0 mission [J].

Aigrain, S. ;

Hodgkin, S. T. ;

Irwin, M. J. ;

Lewis, J. R. ;

Roberts, S. J. .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2015, 447 (03) :2880-2893

[2] The NASA Exoplanet Archive: Data and Tools for Exoplanet Research [J].

Akeson, R. L. ;

Chen, X. ;

Ciardi, D. ;

Crane, M. ;

Good, J. ;

Harbut, M. ;

Jackson, E. ;

Kane, S. R. ;

Laity, A. C. ;

Leifer, S. ;

Lynn, M. ;

McElroy, D. L. ;

Papin, M. ;

Plavchan, P. ;

Ramirez, S. V. ;

Rey, R. ;

von Braun, K. ;

Wittman, M. ;

Abajian, M. ;

Ali, B. ;

Beichman, C. ;

Beekley, A. ;

Berriman, G. B. ;

Berukoff, S. ;

Bryden, G. ;

Chan, B. ;

Groom, S. ;

Lau, C. ;

Payne, A. N. ;

Regelson, M. ;

Saucedo, M. ;

Schmitz, M. ;

Stauffer, J. ;

Wyatt, P. ;

Zhang, A. .

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 2013, 125 (930) :989-999

[3] HATS-7b: A HOT SUPER NEPTUNE TRANSITING A QUIET K DWARF STAR [J].

Bakos, G. A. ;

Penev, K. ;

Bayliss, D. ;

Hartman, J. D. ;

Zhou, G. ;

Brahm, R. ;

Mancini, L. ;

de Val-Borro, M. ;

Bhatti, W. ;

Jordan, A. ;

Rabus, M. ;

Espinoza, N. ;

Csubry, Z. ;

Howard, A. W. ;

Fulton, B. J. ;

Buchhave, L. A. ;

Ciceri, S. ;

Henning, T. ;

Schmidt, B. ;

Isaacson, H. ;

Noyes, R. W. ;

Marcy, G. W. ;

Suc, V. ;

Howe, A. R. ;

Burrows, A. S. ;

Lazar, J. ;

Papp, I. ;

Sari, P. .

ASTROPHYSICAL JOURNAL, 2015, 813 (02)

[4] HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD [J].

Bakos, G. A. ;

Torres, G. ;

Pal, A. ;

Hartman, J. ;

Kovacs, Geza ;

Noyes, R. W. ;

Latham, D. W. ;

Sasselov, D. D. ;

Sipocz, B. ;

Esquerdo, G. A. ;

Fischer, D. A. ;

Johnson, J. A. ;

Marcy, G. W. ;

Butler, R. P. ;

Isaacson, H. ;

Howard, A. ;

Vogt, S. ;

Kovacs, Gabor ;

Fernandez, J. ;

Moor, A. ;

Stefanik, R. P. ;

Lazar, J. ;

Papp, I. ;

Sari, P. .

ASTROPHYSICAL JOURNAL, 2010, 710 (02) :1724-1745

[5] A QUASI-STATIONARY SOLUTION TO GLIESE 436b's ECCENTRICITY [J].

Batygin, Konstantin ;

Laughlin, Gregory ;

Meschiari, Stefano ;

Rivera, Eugenio ;

Vogt, Steve ;

Butler, Paul .

ASTROPHYSICAL JOURNAL, 2009, 699 (01) :23-30

[6] Models of the in situ formation of detected extrasolar giant planets [J].

Bodenheimer, P ;

Hubickyj, O ;

Lissauer, JJ .

ICARUS, 2000, 143 (01) :2-14

[7]

Bonomo A. S., 2014, ARXIV14094592

[8] Transiting exoplanets from the CoRoT space mission XI. CoRoT-8b: a hot and dense sub-Saturn around a K1 dwarf [J].

Borde, P. ;

Bouchy, F. ;

Deleuil, M. ;

Cabrera, J. ;

Jorda, L. ;

Lovis, C. ;

Csizmadia, S. ;

Aigrain, S. ;

Almenara, J. M. ;

Alonso, R. ;

Auvergne, M. ;

Baglin, A. ;

Barge, P. ;

Benz, W. ;

Bonomo, A. S. ;

Bruntt, H. ;

Carone, L. ;

Carpano, S. ;

Deeg, H. ;

Dvorak, R. ;

Erikson, A. ;

Ferraz-Mello, S. ;

Fridlund, M. ;

Gandolfi, D. ;

Gazzano, J. -C. ;

Gillon, M. ;

Guenther, E. ;

Guillot, T. ;

Guterman, P. ;

Hatzes, A. ;

Havel, M. ;

Hebrard, G. ;

Lammer, H. ;

Leger, A. ;

Mayor, M. ;

Mazeh, T. ;

Moutou, C. ;

Paetzold, M. ;

Pepe, F. ;

Ollivier, M. ;

Queloz, D. ;

Rauer, H. ;

Rouan, D. ;

Samuel, B. ;

Santerne, A. ;

Schneider, J. ;

Tingley, B. ;

Udry, S. ;

Weingrill, J. ;

Wuchterl, G. .

ASTRONOMY & ASTROPHYSICS, 2010, 520

[9] KEPLER-4b: A HOT NEPTUNE-LIKE PLANET OF A G0 STAR NEAR MAIN-SEQUENCE TURNOFF [J].

Borucki, William J. ;

Koch, David G. ;

Brown, Timothy M. ;

Basri, Gibor ;

Batalha, Natalie M. ;

Caldwell, Douglas A. ;

Cochran, William D. ;

Dunham, Edward W. ;

Gautier, Thomas N., III ;

Geary, John C. ;

Gilliland, Ronald L. ;

Howell, Steve B. ;

Jenkins, Jon M. ;

Latham, David W. ;

Lissauer, Jack J. ;

Marcy, Geoffrey W. ;

Monet, David ;

Rowe, Jason F. ;

Sasselov, Dimitar .

ASTROPHYSICAL JOURNAL LETTERS, 2010, 713 (02) :L126-L130

[10] Kepler Planet-Detection Mission: Introduction and First Results [J].

Borucki, William J. ;

Koch, David ;

Basri, Gibor ;

Batalha, Natalie ;

Brown, Timothy ;

Caldwell, Douglas ;

Caldwell, John ;

Christensen-Dalsgaard, Jorgen ;

Cochran, William D. ;

DeVore, Edna ;

Dunham, Edward W. ;

Dupree, Andrea K. ;

Gautier, Thomas N., III ;

Geary, John C. ;

Gilliland, Ronald ;

Gould, Alan ;

Howell, Steve B. ;

Jenkins, Jon M. ;

Kondo, Yoji ;

Latham, David W. ;

Marcy, Geoffrey W. ;

Meibom, Soren ;

Kjeldsen, Hans ;

Lissauer, Jack J. ;

Monet, David G. ;

Morrison, David ;

Sasselov, Dimitar ;

Tarter, Jill ;

Boss, Alan ;

Brownlee, Don ;

Owen, Toby ;

Buzasi, Derek ;

Charbonneau, David ;

Doyle, Laurance ;

Fortney, Jonathan ;

Ford, Eric B. ;

Holman, Matthew J. ;

Seager, Sara ;

Steffen, Jason H. ;

Welsh, William F. ;

Rowe, Jason ;

Anderson, Howard ;

Buchhave, Lars ;

Ciardi, David ;

Walkowicz, Lucianne ;

Sherry, William ;

Horch, Elliott ;

Isaacson, Howard ;

Everett, Mark E. ;

Fischer, Debra .

SCIENCE, 2010, 327 (5968) :977-980

← 1 2 3 4 5 6 7 8 9 →