An Unusual Transmission Spectrum for the Sub-Saturn KELT-11b Suggestive of a Subsolar Water Abundance

被引：26

作者：

Colon, Knicole D. ^{[1
,2
]}

Kreidberg, Laura ^{[3
,4
]}

Welbanks, Luis ^{[5
]}

Line, Michael R. ^{[6
]}

Madhusudhan, Nikku ^{[5
]}

Beatty, Thomas ^{[7
,8
]}

Tamburo, Patrick ^{[9
,10
]}

Stevenson, Kevin B. ^{[11
]}

Mandell, Avi ^{[2
,12
]}

Rodriguez, Joseph E. ^{[3
]}

Barclay, Thomas ^{[1
,2
,13
]}

Lopez, Eric D. ^{[2
,12
]}

Stassun, Keivan G. ^{[14
]}

Angerhausen, Daniel ^{[15
,16
]}

Fortney, Jonathan J. ^{[17
]}

James, David J. ^{[18
]}

Pepper, Joshua ^{[19
]}

Ahlers, John P. ^{[1
,2
]}

Plavchan, Peter ^{[20
]}

Awiphan, Supachai ^{[21
]}

Kotnik, Cliff ^{[22
]}

McLeod, Kim K. ^{[23
]}

Murawski, Gabriel ^{[24
]}

Chotani, Heena ^{[20
]}

LeBrun, Danny ^{[20
,25
]}

Matzko, William ^{[20
]}

Rea, David ^{[26
]}

Vidaurri, Monica ^{[20
]}

Webster, Scott ^{[20
]}

Williams, James K. ^{[20
]}

Cox, Leafia Sheraden ^{[23
]}

Tan, Nicole ^{[23
]}

Gilbert, Emily A. ^{[1
,2
,13
,27
,28
]}

机构：

[1] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Code 667, Greenbelt, MD 20771 USA

[2] GSFC Sellers Exoplanet Environm Collaborat, Greenbelt, MD 20770 USA

[3] Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA

[4] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany

[5] Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England

[6] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85257 USA

[7] Univ Arizona, Dept Astron, Tucson, AZ 85721 USA

[8] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA

[9] Boston Univ, Dept Astron, 725 Commonwealth Ave, Boston, MA 02215 USA

[10] Boston Univ, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA

[11] Johns Hopkins APL, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA

[12] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Code 693, Greenbelt, MD 20771 USA

[13] Univ Maryland Baltimore Cty, 1000 Hilltop Circle, Baltimore, MD 21250 USA

[14] Vanderbilt Univ, Dept Phys & Astron, 6301 Stevenson Ctr Lane, Nashville, TN 37235 USA

[15] Swiss Fed Inst Technol, Inst Particle Phys & Astrophys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland

[16] Blue Marble Space Inst Sci, 1001 4th Ave,Suite 3201, Seattle, WA 98154 USA

[17] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA

[18] ASTRAVEO LLC, POB 1668, Gloucester, MA 01931 USA

[19] Lehigh Univ, Dept Phys, 16 Mem Dr East, Bethlehem, PA 18015 USA

[20] George Mason Univ, Dept Phys & Astron, 4400 Univ Dr,MSN 3F3, Fairfax, VA 22030 USA

[21] Natl Astron Res Inst Thailand, 260 Moo 4, Chiang Mai 50180, Thailand

[22] Amer Assoc Variable Star Observers, Cambridge, MA USA

[23] Wellesley Coll, Dept Astron, Wellesley, MA 02481 USA

[24] Gabriel Murawski Private Observ SOTES, Tokyo, Japan

[25] Lockheed Martin, Bethesda, MD 20817 USA

[26] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA

[27] Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA

[28] Adler Planetarium, 1300 South Lakeshore Dr, Chicago, IL 60605 USA

来源：

ASTRONOMICAL JOURNAL | 2020年 / 160卷 / 06期

基金：

英国科学技术设施理事会; 美国国家科学基金会; 美国国家航空航天局;

关键词：

Exoplanet atmospheres; Exoplanet atmospheric composition; Extrasolar gas giants; Exoplanets; EXOMOL LINE LISTS; ERROR-CORRECTION; AB-INITIO; RETRIEVAL; SPECTROSCOPY; TEMPERATURE; RESOLUTION; PLANETS; CLOUDS; IX;

D O I：

10.3847/1538-3881/abc1e9

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present an optical-to-infrared transmission spectrum of the inflated sub-Saturn KELT-11b measured with the Transiting Exoplanet Survey Satellite (TESS), the Hubble Space Telescope (HST) Wide Field Camera 3 G141 spectroscopic grism, and the Spitzer Space Telescope (Spitzer) at 3.6 mu m, in addition to a Spitzer 4.5 mu m secondary eclipse. The precise HST transmission spectrum notably reveals a low-amplitude water feature with an unusual shape. Based on free-retrieval analyses with varying molecular abundances, we find strong evidence for water absorption. Depending on model assumptions, we also find tentative evidence for other absorbers (HCN, TiO, and AlO). The retrieved water abundance is generally less than or similar to 0.1x solar (0.001-0.7x solar over a range of model assumptions), several orders of magnitude lower than expected from planet formation models based on the solar system metallicity trend. We also consider chemical-equilibrium and self-consistent 1D radiative-convective equilibrium model fits and find that they, too, prefer low metallicities ([M/H] less than or similar to -2, consistent with the free-retrieval results). However, all of the retrievals should be interpreted with some caution because they either require additional absorbers that are far out of chemical equilibrium to explain the shape of the spectrum or are simply poor fits to the data. Finally, we find that the Spitzer secondary eclipse is indicative of full heat redistribution from KELT-11b's dayside to nightside, assuming a clear dayside. These potentially unusual results for KELT-11b's composition are suggestive of new challenges on the horizon for atmosphere and formation models in the face of increasingly precise measurements of exoplanet spectra.

引用

页数：25

共 123 条

[11] ExoMol line lists - III. An improved hot rotation-vibration line list for HCN and HNC [J].

Barber, R. J. ;

Strange, J. K. ;

Hill, C. ;

Polyansky, O. L. ;

Mellau, G. Ch. ;

Yurchenko, S. N. ;

Tennyson, Jonathan .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2014, 437 (02) :1828-1835

[12] ExoMol line lists - II. The ro-vibrational spectrum of SiO [J].

Barton, Emma J. ;

Yurchenko, Sergei N. ;

Tennyson, Jonathan .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2013, 434 (02) :1469-1475

[13] Spitzer Phase Curves of KELT-1b and the Signatures of Nightside Clouds in Thermal Phase Observations [J].

Beatty, Thomas G. ;

Marley, Mark S. ;

Gaudi, B. Scott ;

Colon, Knicole D. ;

Fortney, Jonathan J. ;

Showman, Adam P. .

ASTRONOMICAL JOURNAL, 2019, 158 (04)

[14] Determining Empirical Stellar Masses and Radii from Transits and Gaia Parallaxes as Illustrated by Spitzer Observations of KELT-11b [J].

Beatty, Thomas G. ;

Stevens, Daniel J. ;

Collins, Karen A. ;

Colon, Knicole D. ;

James, David J. ;

Kreidberg, Laura ;

Pepper, Joshua ;

Rodriguez, Joseph E. ;

Siverd, Robert J. ;

Stassun, Keivan G. ;

Kielkopf, John F. .

ASTRONOMICAL JOURNAL, 2017, 154 (01)

[15] The CHEOPS mission [J].

Benz, W. ;

Broeg, C. ;

Fortier, A. ;

Rando, N. ;

Beck, T. ;

Beck, M. ;

Queloz, D. ;

Ehrenreich, D. ;

Maxted, P. F. L. ;

Isaak, K. G. ;

Billot, N. ;

Alibert, Y. ;

Alonso, R. ;

Antonio, C. ;

Asquier, J. ;

Bandy, T. ;

Barczy, T. ;

Barrado, D. ;

Barros, S. C. C. ;

Baumjohann, W. ;

Bekkelien, A. ;

Bergomi, M. ;

Biondi, F. ;

Bonfils, X. ;

Borsato, L. ;

Brandeker, A. ;

Busch, M-D ;

Cabrera, J. ;

Cessa, V ;

Charnoz, S. ;

Chazelas, B. ;

Cameron, A. Collier ;

Van Damme, C. Corral ;

Cortes, D. ;

Davies, M. B. ;

Deleuil, M. ;

Deline, A. ;

Delrez, L. ;

Demangeon, O. ;

Demory, B. O. ;

Erikson, A. ;

Farinato, J. ;

Fossati, L. ;

Fridlund, M. ;

Futyan, D. ;

Gandolfi, D. ;

Munoz, A. Garcia ;

Gillon, M. ;

Guterman, P. ;

Gutierrez, A. .

EXPERIMENTAL ASTRONOMY, 2021, 51 (01) :109-151

[16] Chemical enrichment of giant planets and discs due to pebble drift [J].

Booth, Richard A. ;

Clarke, Cathie J. ;

Madhusudhan, Nikku ;

Ilee, John D. .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2017, 469 (04) :3994-4011

[17] Gaia Data Release 2. Summary of the contents and survey properties [J].

Brown, A. G. A. ;

Vallenari, A. ;

Prusti, T. ;

de Bruijne, J. H. J. ;

Babusiaux, C. ;

Bailer-Jones, C. A. L. ;

Biermann, M. ;

Evans, D. W. ;

Eyer, L. ;

Jansen, F. ;

Jordi, C. ;

Klioner, S. A. ;

Lammers, U. ;

Lindegren, L. ;

Luri, X. ;

Mignard, F. ;

Panem, C. ;

Pourbaix, D. ;

Randich, S. ;

Sartoretti, P. ;

Siddiqui, H. I. ;

Soubiran, C. ;

van Leeuwen, F. ;

Walton, N. A. ;

Arenou, F. ;

Bastian, U. ;

Cropper, M. ;

Drimmel, R. ;

Katz, D. ;

Lattanzi, M. G. ;

Bakker, J. ;

Cacciari, C. ;

Castaneda, J. ;

Chaoul, L. ;

Cheek, N. ;

De Angeli, F. ;

Fabricius, C. ;

Guerra, R. ;

Holl, B. ;

Masana, E. ;

Messineo, R. ;

Mowlavi, N. ;

Nienartowicz, K. ;

Panuzzo, P. ;

Portell, J. ;

Riello, M. ;

Seabroke, G. M. ;

Tanga, P. ;

Thevenin, F. ;

Gracia-Abril, G. .

ASTRONOMY & ASTROPHYSICS, 2018, 616

[18] X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue [J].

Buchner, J. ;

Georgakakis, A. ;

Nandra, K. ;

Hsu, L. ;

Rangel, C. ;

Brightman, M. ;

Merloni, A. ;

Salvato, M. ;

Donley, J. ;

Kocevski, D. .

ASTRONOMY & ASTROPHYSICS, 2014, 564

[19] Effects of a fully 3D atmospheric structure on exoplanet transmission spectra: retrieval biases due to day-night temperature gradients [J].

Caldas, A. ;

Leconte, J. ;

Selsis, F. ;

Waldmann, I. P. ;

Borde, P. ;

Rocchetto, M. ;

Charnay, B. .

ASTRONOMY & ASTROPHYSICS, 2019, 623

[20]

Cardoso J.V.d.M.a, 2018, ASCL1812013

← 1 2 3 4 5 6 7 8 9 10 →