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Ground- and Space-based Detection of the Thermal Emission Spectrum of the Transiting Hot Jupiter KELT-2Ab

Piskorz, Danielle and Buzard, Cam and Line, Michael R. and Knutson, Heather A. and Benneke, Björn and Crockett, Nathan R. and Lockwood, Alexandra C. and Blake, Geoffrey A. and Barman, Travis S. and Bender, Chad F. and Deming, Drake and Johnson, John A. (2018) Ground- and Space-based Detection of the Thermal Emission Spectrum of the Transiting Hot Jupiter KELT-2Ab. Astronomical Journal, 156 (3). Art. No. 133. ISSN 1538-3881. doi:10.3847/1538-3881/aad781.

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We describe the detection of water vapor in the atmosphere of the transiting hot Jupiter KELT-2Ab by treating the star–planet system as a spectroscopic binary with high-resolution, ground-based spectroscopy. We resolve the signal of the planet's motion with deep combined flux observations of the star and the planet. In total, six epochs of Keck NIRSPEC L-band observations were obtained, and the full data set was subjected to a cross-correlation analysis with a grid of self-consistent atmospheric models. We measure a radial projection of the Keplerian velocity, K_P , of 148 ± 7 km s^(−1), consistent with transit measurements, and detect water vapor at 3.8σ. We combine NIRSPEC L-band data with Spitzer IRAC secondary eclipse data to further probe the metallicity and carbon-to-oxygen ratio of KELT-2Ab's atmosphere. While the NIRSPEC analysis provides few extra constraints on the Spitzer data, it does provide roughly the same constraints on metallicity and carbon-to-oxygen ratio. This bodes well for future investigations of the atmospheres of non-transiting hot Jupiters.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Piskorz, Danielle0000-0003-4451-2342
Buzard, Cam0000-0002-9943-6124
Line, Michael R.0000-0002-2338-476X
Knutson, Heather A.0000-0002-0822-3095
Benneke, Björn0000-0001-5578-1498
Crockett, Nathan R.0000-0002-6586-7591
Blake, Geoffrey A.0000-0003-0787-1610
Barman, Travis S.0000-0002-7129-3002
Bender, Chad F.0000-0003-4384-7220
Deming, Drake0000-0001-5727-4094
Johnson, John A.0000-0001-9808-7172
Additional Information:© 2018. The American Astronomical Society. Received 2017 August 17; revised 2018 July 8; accepted 2018 July 26; published 2018 August 30. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of MaunaKea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. This work is also based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was partially supported by funding from the NSF Astronomy & Astrophysics and NASA Exoplanets Research Programs (grants AST-1109857 and NNX16AI14G, G.A.B., Principal Investigator (P. I.)). M.R.L would like to thank Richard Freedman and Roxana Lupu for providing pre-tabulated line-by-line absorption cross-sections, Paul Molliere, Ryan Garland, Joanna Barstow, Ingo Waldman, and Marco Rochetto for useful discussions regarding correlated-K, and Ty Robinson and Mark Marley for useful radiative-convective modeling discussions. H.A.K. acknowledges support from the Sloan Foundation. Lastly, we thank an anonymous reviewer for insightful comments that improved the content of this paper.
Group:Astronomy Department
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Subject Keywords:planets and satellites: atmospheres; techniques: spectroscopic
Issue or Number:3
Record Number:CaltechAUTHORS:20180830-145509534
Persistent URL:
Official Citation:Danielle Piskorz et al 2018 AJ 156 133
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:89324
Deposited By: George Porter
Deposited On:04 Sep 2018 14:53
Last Modified:16 Nov 2021 00:34

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