ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b
We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 μm bands of the Spitzer Space Telescope. The 3.6 and 4.5 μm data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest c...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/93877 |
| _version_ | 1826215866741555200 |
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| author | Knutson, Heather A. Showman, Adam P. Cowan, Nicolas B. Laughlin, Gregory Burrows, Adam Deming, Drake Crepp, Justin R. Mighell, Kenneth J. Agol, Eric Bakos, Gaspar A. Charbonneau, David Desert, Jean-Michel Fischer, Debra A. Fortney, Jonathan J. Hartman, Joel D. Hinkley, Sasha Howard, Andrew W. Johnson, John Asher Kao, Melodie M. Langton, Jonathan Marcy, Geoffrey W. Lewis, Nikole |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Knutson, Heather A. Showman, Adam P. Cowan, Nicolas B. Laughlin, Gregory Burrows, Adam Deming, Drake Crepp, Justin R. Mighell, Kenneth J. Agol, Eric Bakos, Gaspar A. Charbonneau, David Desert, Jean-Michel Fischer, Debra A. Fortney, Jonathan J. Hartman, Joel D. Hinkley, Sasha Howard, Andrew W. Johnson, John Asher Kao, Melodie M. Langton, Jonathan Marcy, Geoffrey W. Lewis, Nikole |
| author_sort | Knutson, Heather A. |
| collection | MIT |
| description | We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 μm bands of the Spitzer Space Telescope. The 3.6 and 4.5 μm data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 μm that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 ± 0.28, 5.84 ± 0.39, and 4.68 ± 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% ± 0.0089%, 0.1162% ± 0.0080%, and 0.1888% ± 0.0072% in the 3.6, 4.5, and 8.0 μm bands, respectively. Our measured secondary eclipse depths of 0.0996% ± 0.0072%, 0.1031% ± 0.0061%, 0.071% [+0.029% over -0.013%], and 0.1392% ± 0.0095% in the 3.6, 4.5, 5.8, and 8.0 μm bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 ± 0.00048) and argument of periapse (ω = 188°.09 ± 0°.39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long-term linear trend in the radial velocity data. This trend suggests the presence of another substellar companion in the HAT-P-2 system, which could have caused HAT-P-2b to migrate inward to its present-day orbit via the Kozai mechanism. |
| first_indexed | 2024-09-23T16:38:17Z |
| format | Article |
| id | mit-1721.1/93877 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:38:17Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/938772024-05-15T02:58:46Z ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b Knutson, Heather A. Showman, Adam P. Cowan, Nicolas B. Laughlin, Gregory Burrows, Adam Deming, Drake Crepp, Justin R. Mighell, Kenneth J. Agol, Eric Bakos, Gaspar A. Charbonneau, David Desert, Jean-Michel Fischer, Debra A. Fortney, Jonathan J. Hartman, Joel D. Hinkley, Sasha Howard, Andrew W. Johnson, John Asher Kao, Melodie M. Langton, Jonathan Marcy, Geoffrey W. Lewis, Nikole Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Lewis, Nicole We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 μm bands of the Spitzer Space Telescope. The 3.6 and 4.5 μm data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 μm that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 ± 0.28, 5.84 ± 0.39, and 4.68 ± 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% ± 0.0089%, 0.1162% ± 0.0080%, and 0.1888% ± 0.0072% in the 3.6, 4.5, and 8.0 μm bands, respectively. Our measured secondary eclipse depths of 0.0996% ± 0.0072%, 0.1031% ± 0.0061%, 0.071% [+0.029% over -0.013%], and 0.1392% ± 0.0095% in the 3.6, 4.5, 5.8, and 8.0 μm bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 ± 0.00048) and argument of periapse (ω = 188°.09 ± 0°.39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long-term linear trend in the radial velocity data. This trend suggests the presence of another substellar companion in the HAT-P-2 system, which could have caused HAT-P-2b to migrate inward to its present-day orbit via the Kozai mechanism. United States. National Aeronautics and Space Administration. Jet Propulsion Laboratory (U.S.) United States. National Aeronautics and Space Administration. Earth and Space Science Fellowship Program (NNX08AX02H) United States. National Aeronautics and Space Administration. Origins Program (NNX08AF27G) United States. National Aeronautics and Space Administration. Sagan Fellowship Program (California Institute of Technology) 2015-02-05T20:13:34Z 2015-02-05T20:13:34Z 2013-03 2012-10 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/93877 Lewis, Nikole K., Heather A. Knutson, Adam P. Showman, Nicolas B. Cowan, Gregory Laughlin, Adam Burrows, Drake Deming, et al. “ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b.” The Astrophysical Journal 766, no. 2 (March 13, 2013): 95. © 2013 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/766/2/95 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Knutson, Heather A. Showman, Adam P. Cowan, Nicolas B. Laughlin, Gregory Burrows, Adam Deming, Drake Crepp, Justin R. Mighell, Kenneth J. Agol, Eric Bakos, Gaspar A. Charbonneau, David Desert, Jean-Michel Fischer, Debra A. Fortney, Jonathan J. Hartman, Joel D. Hinkley, Sasha Howard, Andrew W. Johnson, John Asher Kao, Melodie M. Langton, Jonathan Marcy, Geoffrey W. Lewis, Nikole ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title | ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title_full | ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title_fullStr | ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title_full_unstemmed | ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title_short | ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b |
| title_sort | orbital phase variations of the eccentric giant planet hat p 2b |
| url | http://hdl.handle.net/1721.1/93877 |
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