Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391
- Autores
- Jofré, Edgardo; Almenara, J.M.; Petrucci, Romina Paola; Diaz, Rodrigo Fernando; Gómez Maqueo Chew, Y.; Martioli, E.; Ramírez, I.; García, Luciano Héctor; Saffe, Carlos; Canul, E. F.; Buccino, Andrea Paola; Gómez, Marcos Javier; Moreno Hilario, E.
- Año de publicación
- 2019
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Aims. Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these remarkable systems. Methods. Based on high-quality spectra from Gemini-GRACES for Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances for 25 elements. Nine of these elements and the carbon isotopic ratios, 12C∕ 13C, had not previously been measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems. Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of nearby evolved thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE = 1.29 ± 0.09 dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391, along with their high 12C∕ 13C ratios, show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the hot super-Earth desert and, therefore, it might be undergoing photoevaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c's TTV signal, but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp = 56 -13+37 M⊕ ) and Kepler-278c (Mp = 35 -21+9.9 M⊕ ). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e ~ 0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here.
Fil: Jofré, Edgardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
Fil: Almenara, J.M.. Universidad de Ginebra; Suiza
Fil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
Fil: Diaz, Rodrigo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Gómez Maqueo Chew, Y.. Universidad Nacional Autónoma de México; México
Fil: Martioli, E.. Laboratorio Nacional de Astrofísica; Brasil
Fil: Ramírez, I.. Tacoma Community College; Estados Unidos
Fil: García, Luciano Héctor. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
Fil: Saffe, Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina
Fil: Canul, E. F.. Universidad Nacional Autónoma de México; México
Fil: Buccino, Andrea Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Gómez, Marcos Javier. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina
Fil: Moreno Hilario, E.. Universidad Nacional Autónoma de México; México - Materia
-
PLANETARY SYSTEMS
STARS: ABUNDANCES
STARS: FUNDAMENTAL PARAMETERS
STARS: INDIVIDUAL: KEPLER-278
STARS: INDIVIDUAL: KEPLER-391
TECHNIQUES: SPECTROSCOPIC - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
.jpg)
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/129795
Ver los metadatos del registro completo
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Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391Jofré, EdgardoAlmenara, J.M.Petrucci, Romina PaolaDiaz, Rodrigo FernandoGómez Maqueo Chew, Y.Martioli, E.Ramírez, I.García, Luciano HéctorSaffe, CarlosCanul, E. F.Buccino, Andrea PaolaGómez, Marcos JavierMoreno Hilario, E.PLANETARY SYSTEMSSTARS: ABUNDANCESSTARS: FUNDAMENTAL PARAMETERSSTARS: INDIVIDUAL: KEPLER-278STARS: INDIVIDUAL: KEPLER-391TECHNIQUES: SPECTROSCOPIChttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Aims. Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these remarkable systems. Methods. Based on high-quality spectra from Gemini-GRACES for Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances for 25 elements. Nine of these elements and the carbon isotopic ratios, 12C∕ 13C, had not previously been measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems. Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of nearby evolved thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE = 1.29 ± 0.09 dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391, along with their high 12C∕ 13C ratios, show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the hot super-Earth desert and, therefore, it might be undergoing photoevaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c's TTV signal, but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp = 56 -13+37 M⊕ ) and Kepler-278c (Mp = 35 -21+9.9 M⊕ ). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e ~ 0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here.Fil: Jofré, Edgardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Almenara, J.M.. Universidad de Ginebra; SuizaFil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Diaz, Rodrigo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gómez Maqueo Chew, Y.. Universidad Nacional Autónoma de México; MéxicoFil: Martioli, E.. Laboratorio Nacional de Astrofísica; BrasilFil: Ramírez, I.. Tacoma Community College; Estados UnidosFil: García, Luciano Héctor. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Saffe, Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Canul, E. F.. Universidad Nacional Autónoma de México; MéxicoFil: Buccino, Andrea Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gómez, Marcos Javier. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Moreno Hilario, E.. Universidad Nacional Autónoma de México; MéxicoEDP Sciences2019-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/129795Jofré, Edgardo; Almenara, J.M.; Petrucci, Romina Paola; Diaz, Rodrigo Fernando; Gómez Maqueo Chew, Y.; et al.; Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391; EDP Sciences; Astronomy and Astrophysics; 634; 12-2019; 1-330004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201936446info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2020/02/aa36446-19/aa36446-19.htmlinfo:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1912.10278info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T12:19:14Zoai:ri.conicet.gov.ar:11336/129795instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 12:19:15.15CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
| dc.title.none.fl_str_mv |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| title |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| spellingShingle |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 Jofré, Edgardo PLANETARY SYSTEMS STARS: ABUNDANCES STARS: FUNDAMENTAL PARAMETERS STARS: INDIVIDUAL: KEPLER-278 STARS: INDIVIDUAL: KEPLER-391 TECHNIQUES: SPECTROSCOPIC |
| title_short |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| title_full |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| title_fullStr |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| title_full_unstemmed |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| title_sort |
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391 |
| dc.creator.none.fl_str_mv |
Jofré, Edgardo Almenara, J.M. Petrucci, Romina Paola Diaz, Rodrigo Fernando Gómez Maqueo Chew, Y. Martioli, E. Ramírez, I. García, Luciano Héctor Saffe, Carlos Canul, E. F. Buccino, Andrea Paola Gómez, Marcos Javier Moreno Hilario, E. |
| author |
Jofré, Edgardo |
| author_facet |
Jofré, Edgardo Almenara, J.M. Petrucci, Romina Paola Diaz, Rodrigo Fernando Gómez Maqueo Chew, Y. Martioli, E. Ramírez, I. García, Luciano Héctor Saffe, Carlos Canul, E. F. Buccino, Andrea Paola Gómez, Marcos Javier Moreno Hilario, E. |
| author_role |
author |
| author2 |
Almenara, J.M. Petrucci, Romina Paola Diaz, Rodrigo Fernando Gómez Maqueo Chew, Y. Martioli, E. Ramírez, I. García, Luciano Héctor Saffe, Carlos Canul, E. F. Buccino, Andrea Paola Gómez, Marcos Javier Moreno Hilario, E. |
| author2_role |
author author author author author author author author author author author author |
| dc.subject.none.fl_str_mv |
PLANETARY SYSTEMS STARS: ABUNDANCES STARS: FUNDAMENTAL PARAMETERS STARS: INDIVIDUAL: KEPLER-278 STARS: INDIVIDUAL: KEPLER-391 TECHNIQUES: SPECTROSCOPIC |
| topic |
PLANETARY SYSTEMS STARS: ABUNDANCES STARS: FUNDAMENTAL PARAMETERS STARS: INDIVIDUAL: KEPLER-278 STARS: INDIVIDUAL: KEPLER-391 TECHNIQUES: SPECTROSCOPIC |
| purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| dc.description.none.fl_txt_mv |
Aims. Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these remarkable systems. Methods. Based on high-quality spectra from Gemini-GRACES for Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances for 25 elements. Nine of these elements and the carbon isotopic ratios, 12C∕ 13C, had not previously been measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems. Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of nearby evolved thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE = 1.29 ± 0.09 dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391, along with their high 12C∕ 13C ratios, show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the hot super-Earth desert and, therefore, it might be undergoing photoevaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c's TTV signal, but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp = 56 -13+37 M⊕ ) and Kepler-278c (Mp = 35 -21+9.9 M⊕ ). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e ~ 0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here. Fil: Jofré, Edgardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Almenara, J.M.. Universidad de Ginebra; Suiza Fil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Diaz, Rodrigo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Gómez Maqueo Chew, Y.. Universidad Nacional Autónoma de México; México Fil: Martioli, E.. Laboratorio Nacional de Astrofísica; Brasil Fil: Ramírez, I.. Tacoma Community College; Estados Unidos Fil: García, Luciano Héctor. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Saffe, Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina Fil: Canul, E. F.. Universidad Nacional Autónoma de México; México Fil: Buccino, Andrea Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Gómez, Marcos Javier. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Moreno Hilario, E.. Universidad Nacional Autónoma de México; México |
| description |
Aims. Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these remarkable systems. Methods. Based on high-quality spectra from Gemini-GRACES for Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances for 25 elements. Nine of these elements and the carbon isotopic ratios, 12C∕ 13C, had not previously been measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems. Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of nearby evolved thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE = 1.29 ± 0.09 dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391, along with their high 12C∕ 13C ratios, show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the hot super-Earth desert and, therefore, it might be undergoing photoevaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c's TTV signal, but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp = 56 -13+37 M⊕ ) and Kepler-278c (Mp = 35 -21+9.9 M⊕ ). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e ~ 0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here. |
| publishDate |
2019 |
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2019-12 |
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info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
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http://hdl.handle.net/11336/129795 Jofré, Edgardo; Almenara, J.M.; Petrucci, Romina Paola; Diaz, Rodrigo Fernando; Gómez Maqueo Chew, Y.; et al.; Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391; EDP Sciences; Astronomy and Astrophysics; 634; 12-2019; 1-33 0004-6361 CONICET Digital CONICET |
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http://hdl.handle.net/11336/129795 |
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Jofré, Edgardo; Almenara, J.M.; Petrucci, Romina Paola; Diaz, Rodrigo Fernando; Gómez Maqueo Chew, Y.; et al.; Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets: I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391; EDP Sciences; Astronomy and Astrophysics; 634; 12-2019; 1-33 0004-6361 CONICET Digital CONICET |
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eng |
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eng |
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info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201936446 info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2020/02/aa36446-19/aa36446-19.html info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1912.10278 |
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info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
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dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar |
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