The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470
Neptune-size exoplanets seem particularly sensitive to atmospheric evaporation, making it essential to characterize the stellar high-energy radiation that drives this mechanism. This is particularly important with M dwarfs, which emit a large and variable fraction of their luminosity in the ultravio...
| Autores: | , , , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Instituto Nacional de Técnica Aeroespacial (INTA) |
| Repositorio: | DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial |
| OAI Identifier: | oai:digital.inta.es:20.500.12666/744 |
| Acceso en línea: | https://www.aanda.org/articles/aa/abs/2021/06/aa40487-21/aa40487-21.html http://hdl.handle.net/20.500.12666/744 |
| Access Level: | acceso abierto |
| Palabra clave: | Techniques: spectroscopic Planets and satellites: atmospheres Planets and satellites: individual: GJ 3470 Ultraviolet: star Stars: chromospheres |
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| dc.title.none.fl_str_mv |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| title |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| spellingShingle |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 Bourrier, V. Techniques: spectroscopic Planets and satellites: atmospheres Planets and satellites: individual: GJ 3470 Ultraviolet: star Stars: chromospheres |
| title_short |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| title_full |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| title_fullStr |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| title_full_unstemmed |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| title_sort |
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470 |
| dc.creator.none.fl_str_mv |
Bourrier, V. Dos Santos, L. A. Sanz-Forcada, Jorge García Muñoz, Antonio Henry, G. W. Lavvas, P. Lecavelier des Etangs, A. López Morales, M. Mikal Evans, T. Sing, D. K. Wakeford, H. R. Ehrenreich, D. |
| author |
Bourrier, V. |
| author_facet |
Bourrier, V. Dos Santos, L. A. Sanz-Forcada, Jorge García Muñoz, Antonio Henry, G. W. Lavvas, P. Lecavelier des Etangs, A. López Morales, M. Mikal Evans, T. Sing, D. K. Wakeford, H. R. Ehrenreich, D. |
| author_role |
author |
| author2 |
Dos Santos, L. A. Sanz-Forcada, Jorge García Muñoz, Antonio Henry, G. W. Lavvas, P. Lecavelier des Etangs, A. López Morales, M. Mikal Evans, T. Sing, D. K. Wakeford, H. R. Ehrenreich, D. |
| author2_role |
author author author author author author author author author author author |
| dc.contributor.none.fl_str_mv |
European Research Council (ERC) |
| dc.subject.none.fl_str_mv |
Techniques: spectroscopic Planets and satellites: atmospheres Planets and satellites: individual: GJ 3470 Ultraviolet: star Stars: chromospheres |
| topic |
Techniques: spectroscopic Planets and satellites: atmospheres Planets and satellites: individual: GJ 3470 Ultraviolet: star Stars: chromospheres |
| description |
Neptune-size exoplanets seem particularly sensitive to atmospheric evaporation, making it essential to characterize the stellar high-energy radiation that drives this mechanism. This is particularly important with M dwarfs, which emit a large and variable fraction of their luminosity in the ultraviolet and can display strong flaring behavior. The warm Neptune GJ 3470b, hosted by an M2 dwarf, was found to harbor a giant exosphere of neutral hydrogen thanks to three transits observed with the Hubble Space Telescope Imaging Spectrograph (HST/STIS). Here we report on three additional transit observations from the Panchromatic Comparative Exoplanet Treasury program, obtained with the HST Cosmic Origin Spectrograph. These data confirm the absorption signature from GJ 3470b’s exosphere in the stellar Lyman-α line and demonstrate its stability over time. No planetary signatures are detected in other stellar lines, setting a 3σ limit on GJ 3470b’s far-ultraviolet (FUV) radius at 1.3 times its Roche lobe radius. We detect three flares from GJ 3470. They show different spectral energy distributions but peak consistently in the Si III line, which traces intermediate-temperature layers in the transition region. These layers appear to play a particular role in GJ 3470’s activity as emission lines that form at lower or higher temperatures than Si III evolved differently over the long term. Based on the measured emission lines, we derive synthetic X-ray and extreme-ultraviolet (X+EUV, or XUV) spectra for the six observed quiescent phases, covering one year, as well as for the three flaring episodes. Our results suggest that most of GJ 3470’s quiescent high-energy emission comes from the EUV domain, with flares amplifying the FUV emission more strongly. The neutral hydrogen photoionization lifetimes and mass loss derived for GJ 3470b show little variation over the epochs, in agreement with the stability of the exosphere. Simulations informed by our XUV spectra are required to understand the atmospheric structure and evolution of GJ 3470b and the role played by evaporation in the formation of the hot-Neptune desert. |
| publishDate |
2021 |
| dc.date.none.fl_str_mv |
2021 2022 2022 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 |
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article |
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publishedVersion |
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https://www.aanda.org/articles/aa/abs/2021/06/aa40487-21/aa40487-21.html http://hdl.handle.net/20.500.12666/744 |
| url |
https://www.aanda.org/articles/aa/abs/2021/06/aa40487-21/aa40487-21.html http://hdl.handle.net/20.500.12666/744 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.relation.none.fl_str_mv |
Future of upper atmospheric characterisation of exoplanets with spectroscopy A SpectroPhotometric Inquiry of Close-in Exoplanets around the Desert to Understand their Nature and Evolution info:eu-repo/grantAgreement/EC/H2020/724427 info:eu-repo/grantAgreement/EC/H2020/947634 |
| dc.rights.none.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International © ESO 2021 https://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
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Attribution-NonCommercial-NoDerivatives 4.0 International © ESO 2021 https://creativecommons.org/licenses/by-nc-nd/4.0/ |
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openAccess |
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application/pdf |
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EDP Sciences |
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EDP Sciences |
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reponame:DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial instname:Instituto Nacional de Técnica Aeroespacial (INTA) |
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Instituto Nacional de Técnica Aeroespacial (INTA) |
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The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470Bourrier, V.Dos Santos, L. A.Sanz-Forcada, JorgeGarcía Muñoz, AntonioHenry, G. W.Lavvas, P.Lecavelier des Etangs, A.López Morales, M.Mikal Evans, T.Sing, D. K.Wakeford, H. R.Ehrenreich, D.Techniques: spectroscopicPlanets and satellites: atmospheresPlanets and satellites: individual: GJ 3470Ultraviolet: starStars: chromospheresNeptune-size exoplanets seem particularly sensitive to atmospheric evaporation, making it essential to characterize the stellar high-energy radiation that drives this mechanism. This is particularly important with M dwarfs, which emit a large and variable fraction of their luminosity in the ultraviolet and can display strong flaring behavior. The warm Neptune GJ 3470b, hosted by an M2 dwarf, was found to harbor a giant exosphere of neutral hydrogen thanks to three transits observed with the Hubble Space Telescope Imaging Spectrograph (HST/STIS). Here we report on three additional transit observations from the Panchromatic Comparative Exoplanet Treasury program, obtained with the HST Cosmic Origin Spectrograph. These data confirm the absorption signature from GJ 3470b’s exosphere in the stellar Lyman-α line and demonstrate its stability over time. No planetary signatures are detected in other stellar lines, setting a 3σ limit on GJ 3470b’s far-ultraviolet (FUV) radius at 1.3 times its Roche lobe radius. We detect three flares from GJ 3470. They show different spectral energy distributions but peak consistently in the Si III line, which traces intermediate-temperature layers in the transition region. These layers appear to play a particular role in GJ 3470’s activity as emission lines that form at lower or higher temperatures than Si III evolved differently over the long term. Based on the measured emission lines, we derive synthetic X-ray and extreme-ultraviolet (X+EUV, or XUV) spectra for the six observed quiescent phases, covering one year, as well as for the three flaring episodes. Our results suggest that most of GJ 3470’s quiescent high-energy emission comes from the EUV domain, with flares amplifying the FUV emission more strongly. The neutral hydrogen photoionization lifetimes and mass loss derived for GJ 3470b show little variation over the epochs, in agreement with the stability of the exosphere. Simulations informed by our XUV spectra are required to understand the atmospheric structure and evolution of GJ 3470b and the role played by evaporation in the formation of the hot-Neptune desert.Agradecemos al árbitro su apreciada y cuidadosa revisión. Este trabajo se basa en observaciones realizadas con el HST de la NASA/ESA (programa PanCET, GO 14767), obtenidas en el Space Telescope Science Institute (STScI) operado por AURA, Inc. Este trabajo se ha realizado en el marco del Centro Nacional de Competencia en Investigación "PlanetS" apoyado por la Fundación Nacional Suiza para la Ciencia (SNSF). Este proyecto ha recibido financiación del Consejo Europeo de Investigación (ERC) en el marco del programa de investigación e innovación Horizonte 2020 de la Unión Europea (proyecto FOUR ACES acuerdo de subvención nº 724427; proyecto SPICE DUNE; acuerdo de subvención nº 947634). A.L. agradece el apoyo financiero del Centre National d'Études Spatiales (CNES). G.W.H. agradece el apoyo a largo plazo de la NASA, la NSF, la Universidad Estatal de Tennessee y el Estado de Tennessee a través de su programa de Centros de Excelencia.PeerreviewEDP SciencesEuropean Research Council (ERC)202220222021info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501application/pdfhttps://www.aanda.org/articles/aa/abs/2021/06/aa40487-21/aa40487-21.htmlhttp://hdl.handle.net/20.500.12666/744reponame:DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacialinstname:Instituto Nacional de Técnica Aeroespacial (INTA)InglésFuture of upper atmospheric characterisation of exoplanets with spectroscopyA SpectroPhotometric Inquiry of Close-in Exoplanets around the Desert to Understand their Nature and Evolutioninfo:eu-repo/grantAgreement/EC/H2020/724427info:eu-repo/grantAgreement/EC/H2020/947634Attribution-NonCommercial-NoDerivatives 4.0 International© ESO 2021https://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessoai:digital.inta.es:20.500.12666/7442026-06-23T12:46:37Z |
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15.300724 |