KELT-24b: A 5M J Planet on a 5.6 day Well-aligned Orbit around the Young V = 8.3 F-star HD 93148
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Latham, David W.
Stassun, Keivan G. Christiansen, Jessie L. Jang-Condell, Hannah Johnson, John A. Wright, Jason T.
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Univ Arizona, Dept Astron & Steward ObservIssue Date
2019-10-23Metadata
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IOP PUBLISHING LTDCitation
Joseph E. Rodriguez et al 2019 AJ 158 197Journal
ASTRONOMICAL JOURNALRights
Copyright © 2019. The American Astronomical Society. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V = 8.3 mag, K = 7.2 mag) young F-star with a period of 5.6 days. The host star, KELT-24 (HD 93148), has a T-eff = 6509(-49)(+50) K, a mass of M-* = 1.460(-0.059)(+0.055) M-circle dot, a radius of R-* = 1.506 +/- 0.022 R-circle dot, and an age of 0.78(-0.42)(+0.61) Gyr. Its planetary companion (KELT-24 b) has a radius of R-P = 1.272 +/- 0.021 R-J and a mass of M-P = 5.18(-0.22)(+0.21) M-J, and from Doppler tomographic observations, we find that the planet's orbit is well-aligned to its host star's projected spin axis (lambda = 2.6(-3.6)(+5.1)). The young age estimated for KELT-24 suggests that it only recently started to evolve from the zero-age main sequence. KELT-24 is the brightest star known to host a transiting giant planet with a period between 5 and 10 days. Although the circularization timescale is much longer than the age of the system, we do not detect a large eccentricity or significant misalignment that is expected from dynamical migration. The brightness of its host star and its moderate surface gravity make KELT-24b an intriguing target for detailed atmospheric characterization through spectroscopic emission measurements since it would bridge the current literature results that have primarily focused on lower mass hot Jupiters and a few brown dwarfs.ISSN
0004-6256Version
Final published versionSponsors
Harvard Future Faculty Leaders Postdoctoral fellowship; Space Telescope Science InstituteSpace Telescope Science Institute [HST-HF2-51402.001-A]; Vanderbilt Office of the Provost through the Vanderbilt Initiative in Data-intensive Astrophysics; JSPS KAKENHIMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of ScienceGrants-in-Aid for Scientific Research (KAKENHI) [JP18H01265, JP18H05439]; JST PRESTO grant [JPMJPR1775]; FAPESPFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2017/23731-1]; NASANational Aeronautics & Space Administration (NASA) [80NSSC18K1009, NNX17AB94G, MT-13EPSCoR-0011, NAS 5-26555]; National Aeronautics and Space Administration (EPSCOR grant) [NNX13AM97A]; Australian Research Council (LIEF grant)Australian Research Council [LE140100050]; National Science FoundationNational Science Foundation (NSF) [1516242, 1608203]; Pennsylvania State University; Eberly College of Science; Pennsylvania Space Grant Consortium; Gordon and Betty Moore FoundationGordon and Betty Moore Foundation [GBMF5490]; NSFNational Science Foundation (NSF) [AST-1515927]; Mt. Cuba Astronomical Foundation; Center for Cosmology and AstroParticle Physics (CCAPP) at OSU; Chinese Academy of Sciences South America Center for Astronomy (CASSACA); Villum Fonden (Denmark)Scopus Count
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