Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets
We present an improved formula for the anomalous radial velocity of the star during planetary transits due to the Rossiter-McLaughlin (RM) effect. The improvement comes from a more realistic description of the stellar absorption line profiles, taking into account stellar rotation, macroturbulence, t...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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IOP Publishing
2012
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| Online Access: | http://hdl.handle.net/1721.1/72017 https://orcid.org/0000-0002-4265-047X |
| _version_ | 1811094628218175488 |
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| author | Hirano, Teruyuki Suto, Yasushi Winn, Joshua Nathan Taruya, Atshushi Narita, Norio Albrecht, Simon H. Sato, Bunei |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Hirano, Teruyuki Suto, Yasushi Winn, Joshua Nathan Taruya, Atshushi Narita, Norio Albrecht, Simon H. Sato, Bunei |
| author_sort | Hirano, Teruyuki |
| collection | MIT |
| description | We present an improved formula for the anomalous radial velocity of the star during planetary transits due to the Rossiter-McLaughlin (RM) effect. The improvement comes from a more realistic description of the stellar absorption line profiles, taking into account stellar rotation, macroturbulence, thermal broadening, pressure broadening, and instrumental broadening. Although the formula is derived for the case in which radial velocities are measured by cross-correlation, we show through numerical simulations that the formula accurately describes the cases where the radial velocities are measured with the iodine absorption-cell technique. The formula relies on prior knowledge of the parameters describing macroturbulence, instrumental broadening, and other broadening mechanisms, but even 30% errors in those parameters do not significantly change the results in typical circumstances. We show that the new analytic formula agrees with previous ones that had been computed on a case-by-case basis via numerical simulations. Finally, as one application of the new formula, we reassess the impact of the differential rotation on the RM velocity anomaly. We show that differential rotation of a rapidly rotating star may have a significant impact on future RM observations. |
| first_indexed | 2024-09-23T16:03:03Z |
| format | Article |
| id | mit-1721.1/72017 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:03:03Z |
| publishDate | 2012 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/720172022-10-02T05:59:19Z Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets Hirano, Teruyuki Suto, Yasushi Winn, Joshua Nathan Taruya, Atshushi Narita, Norio Albrecht, Simon H. Sato, Bunei Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Winn, Joshua Nathan Hirano, Teruyuki Winn, Joshua Nathan Albrecht, Simon H. We present an improved formula for the anomalous radial velocity of the star during planetary transits due to the Rossiter-McLaughlin (RM) effect. The improvement comes from a more realistic description of the stellar absorption line profiles, taking into account stellar rotation, macroturbulence, thermal broadening, pressure broadening, and instrumental broadening. Although the formula is derived for the case in which radial velocities are measured by cross-correlation, we show through numerical simulations that the formula accurately describes the cases where the radial velocities are measured with the iodine absorption-cell technique. The formula relies on prior knowledge of the parameters describing macroturbulence, instrumental broadening, and other broadening mechanisms, but even 30% errors in those parameters do not significantly change the results in typical circumstances. We show that the new analytic formula agrees with previous ones that had been computed on a case-by-case basis via numerical simulations. Finally, as one application of the new formula, we reassess the impact of the differential rotation on the RM velocity anomaly. We show that differential rotation of a rapidly rotating star may have a significant impact on future RM observations. United States. National Aeronautics and Space Administration (Origins program grant NNX11AG85G) 2012-08-07T15:52:52Z 2012-08-07T15:52:52Z 2011-11 2011-08 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/72017 Hirano, Teruyuki et al. “IMPROVED MODELING OF THE ROSSITER-McLAUGHLIN EFFECT FOR TRANSITING EXOPLANETS.” The Astrophysical Journal 742.2 (2011): 69. https://orcid.org/0000-0002-4265-047X en_US http://dx.doi.org/10.1088/0004-637x/742/2/69 Astrophysical Journal Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf IOP Publishing Prof. Winn via Mat Willmott |
| spellingShingle | Hirano, Teruyuki Suto, Yasushi Winn, Joshua Nathan Taruya, Atshushi Narita, Norio Albrecht, Simon H. Sato, Bunei Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title | Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title_full | Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title_fullStr | Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title_full_unstemmed | Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title_short | Improved modeling of the Rossiter-McLaughlin effect for transiting exoplanets |
| title_sort | improved modeling of the rossiter mclaughlin effect for transiting exoplanets |
| url | http://hdl.handle.net/1721.1/72017 https://orcid.org/0000-0002-4265-047X |
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