HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF
Abstract
We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V approx 12.8 K4 dwarf GSC 03033 - 00706, with a period P = 3.2130598 +- 0.0000021 d, transit epoch T{sub c} = 2454419.19556 +- 0.00020 (BJD), and transit duration 0.0974 +- 0.0006 d. The host star has a mass of 0.73 +- 0.02 M{sub sun}, radius of 0.70{sup +0.02}{sub -0.01} R{sub sun}, effective temperature 4650 +- 60 K, and metallicity [Fe/H] = -0.29 +- 0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a planet. We conclude that a model consisting of a single star with a transiting planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the planetary companion has a mass of 0.211 +- 0.012 M{sub J} and radius of 0.959{sup +0.029}{sub -0.021} R{sub J} yielding a mean density of 0.295 +- 0.025 g cm{sup -3}. Comparing these observations withmore »
- Authors:
-
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
- Konkoly Observatory, Budapest (Hungary)
- Department of Physics and Astronomy, San Francisco State University, San Francisco, CA (United States)
- Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
- Department of Astronomy, University of California, Berkeley, CA (United States)
- Department of Terrestrial Magnetism, Carnegie Institute of Washington, DC (United States)
- Hungarian Astronomical Association, Budapest (Hungary)
- Publication Date:
- OSTI Identifier:
- 21378141
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 706; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/706/1/785; Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; MASS; METALS; RADIAL VELOCITY; SATURN PLANET; STARS; ELEMENTS; PLANETS; VELOCITY
Citation Formats
Hartman, J D, Bakos, G A, Torres, G, Noyes, R W, Pal, A, Latham, D W, Sipocz, B, Esquerdo, G A, Sasselov, D D, Kovacs, Gabor, Stefanik, R P, Fernandez, J M, Kovacs, Geza, Fischer, D A, Johnson, J A, Marcy, G W, Howard, A W, Butler, R P, Lazar, J, and Papp, I. HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF. United States: N. p., 2009.
Web. doi:10.1088/0004-637X/706/1/785.
Hartman, J D, Bakos, G A, Torres, G, Noyes, R W, Pal, A, Latham, D W, Sipocz, B, Esquerdo, G A, Sasselov, D D, Kovacs, Gabor, Stefanik, R P, Fernandez, J M, Kovacs, Geza, Fischer, D A, Johnson, J A, Marcy, G W, Howard, A W, Butler, R P, Lazar, J, & Papp, I. HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF. United States. https://doi.org/10.1088/0004-637X/706/1/785
Hartman, J D, Bakos, G A, Torres, G, Noyes, R W, Pal, A, Latham, D W, Sipocz, B, Esquerdo, G A, Sasselov, D D, Kovacs, Gabor, Stefanik, R P, Fernandez, J M, Kovacs, Geza, Fischer, D A, Johnson, J A, Marcy, G W, Howard, A W, Butler, R P, Lazar, J, and Papp, I. 2009.
"HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF". United States. https://doi.org/10.1088/0004-637X/706/1/785.
@article{osti_21378141,
title = {HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF},
author = {Hartman, J D and Bakos, G A and Torres, G and Noyes, R W and Pal, A and Latham, D W and Sipocz, B and Esquerdo, G A and Sasselov, D D and Kovacs, Gabor and Stefanik, R P and Fernandez, J M and Kovacs, Geza and Fischer, D A and Johnson, J A and Marcy, G W and Howard, A W and Butler, R P and Lazar, J and Papp, I},
abstractNote = {We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V approx 12.8 K4 dwarf GSC 03033 - 00706, with a period P = 3.2130598 +- 0.0000021 d, transit epoch T{sub c} = 2454419.19556 +- 0.00020 (BJD), and transit duration 0.0974 +- 0.0006 d. The host star has a mass of 0.73 +- 0.02 M{sub sun}, radius of 0.70{sup +0.02}{sub -0.01} R{sub sun}, effective temperature 4650 +- 60 K, and metallicity [Fe/H] = -0.29 +- 0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a planet. We conclude that a model consisting of a single star with a transiting planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the planetary companion has a mass of 0.211 +- 0.012 M{sub J} and radius of 0.959{sup +0.029}{sub -0.021} R{sub J} yielding a mean density of 0.295 +- 0.025 g cm{sup -3}. Comparing these observations with recent theoretical models, we find that HAT-P-12b is consistent with a approx1-4.5 Gyr, mildly irradiated, H/He-dominated planet with a core mass M{sub C} approx< 10 M {sub +}. HAT-P-12b is thus the least massive H/He-dominated gas giant planet found to date. This record was previously held by Saturn.},
doi = {10.1088/0004-637X/706/1/785},
url = {https://www.osti.gov/biblio/21378141},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 706,
place = {United States},
year = {Fri Nov 20 00:00:00 EST 2009},
month = {Fri Nov 20 00:00:00 EST 2009}
}