Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses
© 2020. The American Astronomical Society. All rights reserved. Stellar activity remains a limiting factor in measuring precise planet parameters from radial velocity spectroscopy, not least in the search for Earth-mass planets orbiting in the habitable zones of Sun-like stars. One approach to mitig...
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Language: | English |
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American Astronomical Society
2021
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Online Access: | https://hdl.handle.net/1721.1/135320 |
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author | Kosiarek, Molly R Crossfield, Ian JM |
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 Kosiarek, Molly R Crossfield, Ian JM |
author_sort | Kosiarek, Molly R |
collection | MIT |
description | © 2020. The American Astronomical Society. All rights reserved. Stellar activity remains a limiting factor in measuring precise planet parameters from radial velocity spectroscopy, not least in the search for Earth-mass planets orbiting in the habitable zones of Sun-like stars. One approach to mitigate stellar activity is to use combined analyses of both radial velocity and time-series photometry. We present an analysis of simultaneous disk-integrated photometry and radial velocity data of the Sun in order to determine the useful limits of a combined analysis. We find that simple periodogram or autocorrelation analysis of solar photometry give the correct rotation period <50% of the time. We therefore use a Gaussian process to investigate the time variability of solar photometry and to directly compare simultaneous photometry with radial velocity data. We find that the hyperparameter posteriors are relatively stable over 70 yr of solar photometry and the amplitude tracks the solar cycle. We observe good agreement between the hyperparameter posteriors for the simultaneous photometry and radial velocity data. Our primary conclusion is a recommendation to include an additional prior in Gaussian process fits to constrain the evolutionary timescale to be greater than the recurrence timescale (i.e., the rotation period) to recover more physically plausible and useful results. Our results indicate that such simultaneous monitoring may be a useful tool in enhancing the precision of radial velocity surveys. |
first_indexed | 2024-09-23T13:21:13Z |
format | Article |
id | mit-1721.1/135320 |
institution | Massachusetts Institute of Technology |
language | English |
last_indexed | 2024-09-23T13:21:13Z |
publishDate | 2021 |
publisher | American Astronomical Society |
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spelling | mit-1721.1/1353202023-02-17T16:28:13Z Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses Kosiarek, Molly R Crossfield, Ian JM Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Department of Aeronautics and Astronautics © 2020. The American Astronomical Society. All rights reserved. Stellar activity remains a limiting factor in measuring precise planet parameters from radial velocity spectroscopy, not least in the search for Earth-mass planets orbiting in the habitable zones of Sun-like stars. One approach to mitigate stellar activity is to use combined analyses of both radial velocity and time-series photometry. We present an analysis of simultaneous disk-integrated photometry and radial velocity data of the Sun in order to determine the useful limits of a combined analysis. We find that simple periodogram or autocorrelation analysis of solar photometry give the correct rotation period <50% of the time. We therefore use a Gaussian process to investigate the time variability of solar photometry and to directly compare simultaneous photometry with radial velocity data. We find that the hyperparameter posteriors are relatively stable over 70 yr of solar photometry and the amplitude tracks the solar cycle. We observe good agreement between the hyperparameter posteriors for the simultaneous photometry and radial velocity data. Our primary conclusion is a recommendation to include an additional prior in Gaussian process fits to constrain the evolutionary timescale to be greater than the recurrence timescale (i.e., the rotation period) to recover more physically plausible and useful results. Our results indicate that such simultaneous monitoring may be a useful tool in enhancing the precision of radial velocity surveys. 2021-10-27T20:22:57Z 2021-10-27T20:22:57Z 2020 2021-03-19T15:18:28Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/135320 en 10.3847/1538-3881/AB8D3A Astronomical 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 American Astronomical Society The American Astronomical Society |
spellingShingle | Kosiarek, Molly R Crossfield, Ian JM Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title | Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title_full | Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title_fullStr | Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title_full_unstemmed | Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title_short | Photometry as a Proxy for Stellar Activity in Radial Velocity Analyses |
title_sort | photometry as a proxy for stellar activity in radial velocity analyses |
url | https://hdl.handle.net/1721.1/135320 |
work_keys_str_mv | AT kosiarekmollyr photometryasaproxyforstellaractivityinradialvelocityanalyses AT crossfieldianjm photometryasaproxyforstellaractivityinradialvelocityanalyses |