HAT-P-57b: A Short-period Giant Planet Transiting a Bright Rapidly Rotating A8V Star Confirmed Via Doppler Tomography
Article
Article Title | HAT-P-57b: A Short-period Giant Planet Transiting a Bright Rapidly Rotating A8V Star Confirmed Via Doppler Tomography |
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ERA Journal ID | 1048 |
Article Category | Article |
Authors | Hartman, J. D. (Author), Bakos, G. A. (Author), Buchhave, L. A. (Author), Torres, G. (Author), Latham, D. W. (Author), Kovacs, G. (Author), Bhatti, W. (Author), Csubry, Z. (Author), de Val-Borro, M. (Author), Penev, K. (Author), Huang, C. X. (Author), Beky, B. (Author), Bieryla, A. (Author), Quinn, S. N. (Author), Howard, A. W. (Author), Marcy, G. W. (Author), Johnson, J. A. (Author), Isaacson, H. (Author), Fischer, D. A. (Author), Noyes, R. W. (Author), Falco, E. (Author), Esquerdo, G. A. (Author), Knox, R. P. (Author), Hinz, P. (Author), Lazar, J. (Author), Papp, I. (Author) and Sari, P. (Author) |
Journal Title | The Astronomical Journal |
Journal Citation | 150 (6), pp. 1-17 |
Article Number | 197 |
Number of Pages | 17 |
Year | 2015 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-6256 |
1538-3881 | |
Digital Object Identifier (DOI) | https://doi.org/10.1088/0004-6256/150/6/197 |
Web Address (URL) | https://iopscience.iop.org/article/10.1088/0004-6256/150/6/197 |
Abstract | We present the discovery of HAT-P-57b, a P = 2.4653 day transiting planet around a V = 10.465 ± 0.029 mag, Teff = 7500 ± 250 K main sequence A8V star with a projected rotation velocity of v sin i = 102.1 ± 1.3 km s-1. We measure the radius of the planet to be R = 1.413 ± 0.054 RJ and, based on RV observations, place a 95% confidence upper limit on its mass of M < 1.85 MJ. Based on theoretical stellar evolution models, the host star has a mass and radius of 1.47 ± 0.12 M and 1.500 ± 0.050 R, respectively. Spectroscopic observations made with Keck-I/HIRES during a partial transit event show the Doppler shadow of HAT-P-57b moving across the average spectral line profile of HAT-P-57, confirming the object as a planetary system. We use these observations, together with analytic formulae that we derive for the line profile distortions, to determine the projected angle between the spin axis of HAT-P-57 and the orbital axis of HAT-P-57b. The data permit two possible solutions, with -16°.7 < l < 3°.3 or 27°.6 < l < 57°.4 at 95% confidence, and with relative probabilities for the two modes of 26% and 74%, respectively. Adaptive optics imaging with MMT/Clio2 reveals an object located 2.7 from HAT-P-57 consisting of two point sources separated in turn from each other by 0.22. The H- and L-band magnitudes of the companion stars are consistent with their being physically associated with HAT-P-57, in which case they are stars of mass 0.61 ± 0.10 M and 0.53 ± 0.08 M. HAT-P-57 is the most rapidly rotating star, and only the fourth main sequence A star, known to host a transiting planet. |
Keywords | planetary systems; stars: individual (HAT-P-57); techniques: photometric; techniques: spectroscopic; Astrophysics - Earth and Planetary Astrophysics |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | For access to this article, please click on the URL link provided. |
Institution of Origin | University of Southern Queensland |
Byline Affiliations | Princeton University, United States |
Center for Astrophysics Harvard and Smithsonian, United States | |
Konkoly Observatory, Hungary | |
Google, United States | |
Georgia State University, United States | |
University of Hawaii, United States | |
University of California, United States | |
Yale University, United States | |
University of Arizona, United States | |
Hungarian Astronomical Association, Hungary |
https://research.usq.edu.au/item/q725q/hat-p-57b-a-short-period-giant-planet-transiting-a-bright-rapidly-rotating-a8v-star-confirmed-via-doppler-tomography
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