HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star
We report the discovery by the HATSouth network of HATS-7b, a transiting Super-Neptune with a mass of 0.120 ± 0.012 M_J, a radius of 0.563_(-0.034)^(+0.046) R_J, and an orbital period of 3.1853 days. The host star is a moderately bright (V = 13.340 ± 0.010 mag, K_S = 10.976 ± 0.026 mag) K dwarf s...
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ftcaltechauth:oai:authors.library.caltech.edu:54f13-d0032 2024-10-06T13:49:30+00:00 HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star Bakos, G. Ã. Howard, A. W. Fulton, B. J. 2015-11-10 https://doi.org/10.1088/0004-637X/813/2/111 unknown American Astronomical Society https://arxiv.org/abs/1507.01024 eprintid:78357 info:eu-repo/semantics/openAccess Other Astrophysical Journal, 813(2), Art. No. 111, (2015-11-10) stars: individual (HATS-7) techniques: photometric techniques: radial velocities techniques: spectroscopic info:eu-repo/semantics/article 2015 ftcaltechauth https://doi.org/10.1088/0004-637X/813/2/111 2024-09-25T18:46:43Z We report the discovery by the HATSouth network of HATS-7b, a transiting Super-Neptune with a mass of 0.120 ± 0.012 M_J, a radius of 0.563_(-0.034)^(+0.046) R_J, and an orbital period of 3.1853 days. The host star is a moderately bright (V = 13.340 ± 0.010 mag, K_S = 10.976 ± 0.026 mag) K dwarf star with a mass of 0.849 ± 0.027 M_⊙, a radius of 0.815_(-0.035)^(+0.049) R_⊙, and a metallicity of [Fe/H] = + 0.250 ± 0.080. The star is photometrically quiet to within the precision of the HATSouth measurements, has low RV jitter, and shows no evidence for chromospheric activity in its spectrum. HATS-7b is the second smallest radius planet discovered by a wide-field ground-based transit survey, and one of only a handful of Neptune-size planets with mass and radius determined to 10% precision. Theoretical modeling of HATS-7b yields a hydrogen–helium fraction of 18 ± 4% (rock-iron core and H_2–He envelope), or 9 ± 4% (ice core and H_2–He envelope), i.e., it has a composition broadly similar to that of Uranus and Neptune, and very different from that of Saturn, which has 75% of its mass in H_2–He. Based on a sample of transiting exoplanets with accurately (<20%) determined parameters, we establish approximate power-law relations for the envelopes of the mass–density distribution of exoplanets. HATS-7b, which, together with the recently discovered HATS-8b, is one of the first two transiting super-Neptunes discovered in the Southern sky, is a prime target for additional follow-up observations with Southern hemisphere facilities to characterize the atmospheres of Super-Neptunes (which we define as objects with mass greater than that of Neptune, and smaller than halfway between that of Neptune and Saturn, i.e., 0.054 M_J < M_p < 0.18 M_J). © 2015. The American Astronomical Society. Received 2015 July 3. Accepted 2015 September 14. Published 2015 November 4. Development of the HATSouth project was funded by NSF MRI grant NSF/AST-0723074, operations have been supported by NASA grants NNX09AB29G ... Article in Journal/Newspaper ice core Caltech Authors (California Institute of Technology) The Astrophysical Journal 813 2 111 |
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Caltech Authors (California Institute of Technology) |
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stars: individual (HATS-7) techniques: photometric techniques: radial velocities techniques: spectroscopic |
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stars: individual (HATS-7) techniques: photometric techniques: radial velocities techniques: spectroscopic Bakos, G. Ã. Howard, A. W. Fulton, B. J. HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
topic_facet |
stars: individual (HATS-7) techniques: photometric techniques: radial velocities techniques: spectroscopic |
description |
We report the discovery by the HATSouth network of HATS-7b, a transiting Super-Neptune with a mass of 0.120 ± 0.012 M_J, a radius of 0.563_(-0.034)^(+0.046) R_J, and an orbital period of 3.1853 days. The host star is a moderately bright (V = 13.340 ± 0.010 mag, K_S = 10.976 ± 0.026 mag) K dwarf star with a mass of 0.849 ± 0.027 M_⊙, a radius of 0.815_(-0.035)^(+0.049) R_⊙, and a metallicity of [Fe/H] = + 0.250 ± 0.080. The star is photometrically quiet to within the precision of the HATSouth measurements, has low RV jitter, and shows no evidence for chromospheric activity in its spectrum. HATS-7b is the second smallest radius planet discovered by a wide-field ground-based transit survey, and one of only a handful of Neptune-size planets with mass and radius determined to 10% precision. Theoretical modeling of HATS-7b yields a hydrogen–helium fraction of 18 ± 4% (rock-iron core and H_2–He envelope), or 9 ± 4% (ice core and H_2–He envelope), i.e., it has a composition broadly similar to that of Uranus and Neptune, and very different from that of Saturn, which has 75% of its mass in H_2–He. Based on a sample of transiting exoplanets with accurately (<20%) determined parameters, we establish approximate power-law relations for the envelopes of the mass–density distribution of exoplanets. HATS-7b, which, together with the recently discovered HATS-8b, is one of the first two transiting super-Neptunes discovered in the Southern sky, is a prime target for additional follow-up observations with Southern hemisphere facilities to characterize the atmospheres of Super-Neptunes (which we define as objects with mass greater than that of Neptune, and smaller than halfway between that of Neptune and Saturn, i.e., 0.054 M_J < M_p < 0.18 M_J). © 2015. The American Astronomical Society. Received 2015 July 3. Accepted 2015 September 14. Published 2015 November 4. Development of the HATSouth project was funded by NSF MRI grant NSF/AST-0723074, operations have been supported by NASA grants NNX09AB29G ... |
format |
Article in Journal/Newspaper |
author |
Bakos, G. Ã. Howard, A. W. Fulton, B. J. |
author_facet |
Bakos, G. Ã. Howard, A. W. Fulton, B. J. |
author_sort |
Bakos, G. Ã. |
title |
HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
title_short |
HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
title_full |
HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
title_fullStr |
HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
title_full_unstemmed |
HATS-7b: A Hot Super Neptune Transiting a Quiet K Dwarf Star |
title_sort |
hats-7b: a hot super neptune transiting a quiet k dwarf star |
publisher |
American Astronomical Society |
publishDate |
2015 |
url |
https://doi.org/10.1088/0004-637X/813/2/111 |
genre |
ice core |
genre_facet |
ice core |
op_source |
Astrophysical Journal, 813(2), Art. No. 111, (2015-11-10) |
op_relation |
https://arxiv.org/abs/1507.01024 eprintid:78357 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1088/0004-637X/813/2/111 |
container_title |
The Astrophysical Journal |
container_volume |
813 |
container_issue |
2 |
container_start_page |
111 |
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1812177585294016512 |