Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle

Autores
Ibañez Bustos, Romina Valeria; Buccino, Andrea Paola; Messina, S.; Lanza, A. F.; Mauas, Pablo Jacobo David
Año de publicación
2020
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Aims. Recently, new debates about the role of layers of strong shear have emerged in stellar dynamo theory. Further information on the long-term magnetic activity of fully convective stars could help determine whether their underlying dynamo could sustain activity cycles similar to the solar one. Methods. We performed a thorough study of the short- and long-term magnetic activity of the young active dM4 star Gl 729. First, we analyzed long-cadence K2 photometry to characterize its transient events (e.g., flares) and global and surface differential rotation. Then, from the Mount Wilson S-indexes derived from CASLEO spectra and other public observations, we analyzed its long-term activity between 1998 and 2020 with four different time-domain techniques to detect cyclic patterns. Finally, we explored the chromospheric activity at different heights with simultaneous measurements of the Hα and the Na I D indexes, and we analyzed their relations with the S-Index. Results. We found that the cumulative flare frequency follows a power-law distribution with slope ~-0.73 for the range 1032-1034 erg. We obtained Prot = (2.848 ± 0.001) days, and we found no evidence of differential rotation. We also found that this young active star presents a long-term activity cycle with a length of about 4 yr; there is less significant evidence of a shorter cycle of 0.8 yr. The star also shows a broad activity minimum between 1998 and 2004. We found a correlation between the S index, on the one hand, and the Hα the Na I D indexes, on the other hand, although the saturation level of these last two indexes is not observed in the Ca lines. Conclusions. Because the maximum-entropy spot model does not reflect migration between active longitudes, this activity cycle cannot be explained by a solar-type dynamo. It is probably caused by an α2-dynamo.
Fil: Ibañez Bustos, Romina Valeria. 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: 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: Messina, S.. Osservatorio Astrofisico di Catania; Italia
Fil: Lanza, A. F.. Osservatorio Astrofisico di Catania; Italia
Fil: Mauas, Pablo Jacobo David. 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
Materia
STARS: ACTIVITY
STARS: LATE-TYPE
TECHNIQUES: SPECTROSCOPIC
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/162555

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network_name_str CONICET Digital (CONICET)
spelling Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycleIbañez Bustos, Romina ValeriaBuccino, Andrea PaolaMessina, S.Lanza, A. F.Mauas, Pablo Jacobo DavidSTARS: ACTIVITYSTARS: LATE-TYPETECHNIQUES: SPECTROSCOPIChttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Aims. Recently, new debates about the role of layers of strong shear have emerged in stellar dynamo theory. Further information on the long-term magnetic activity of fully convective stars could help determine whether their underlying dynamo could sustain activity cycles similar to the solar one. Methods. We performed a thorough study of the short- and long-term magnetic activity of the young active dM4 star Gl 729. First, we analyzed long-cadence K2 photometry to characterize its transient events (e.g., flares) and global and surface differential rotation. Then, from the Mount Wilson S-indexes derived from CASLEO spectra and other public observations, we analyzed its long-term activity between 1998 and 2020 with four different time-domain techniques to detect cyclic patterns. Finally, we explored the chromospheric activity at different heights with simultaneous measurements of the Hα and the Na I D indexes, and we analyzed their relations with the S-Index. Results. We found that the cumulative flare frequency follows a power-law distribution with slope ~-0.73 for the range 1032-1034 erg. We obtained Prot = (2.848 ± 0.001) days, and we found no evidence of differential rotation. We also found that this young active star presents a long-term activity cycle with a length of about 4 yr; there is less significant evidence of a shorter cycle of 0.8 yr. The star also shows a broad activity minimum between 1998 and 2004. We found a correlation between the S index, on the one hand, and the Hα the Na I D indexes, on the other hand, although the saturation level of these last two indexes is not observed in the Ca lines. Conclusions. Because the maximum-entropy spot model does not reflect migration between active longitudes, this activity cycle cannot be explained by a solar-type dynamo. It is probably caused by an α2-dynamo.Fil: Ibañez Bustos, Romina Valeria. 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: 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: Messina, S.. Osservatorio Astrofisico di Catania; ItaliaFil: Lanza, A. F.. Osservatorio Astrofisico di Catania; ItaliaFil: Mauas, Pablo Jacobo David. 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; ArgentinaEDP Sciences2020-11info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/162555Ibañez Bustos, Romina Valeria; Buccino, Andrea Paola; Messina, S.; Lanza, A. F.; Mauas, Pablo Jacobo David; Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle; EDP Sciences; Astronomy and Astrophysics; 644; 11-2020; 1-140004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/10.1051/0004-6361/202039164info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202039164info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:01:57Zoai:ri.conicet.gov.ar:11336/162555instacron: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:34982025-09-29 10:01:57.71CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
title Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
spellingShingle Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
Ibañez Bustos, Romina Valeria
STARS: ACTIVITY
STARS: LATE-TYPE
TECHNIQUES: SPECTROSCOPIC
title_short Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
title_full Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
title_fullStr Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
title_full_unstemmed Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
title_sort Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle
dc.creator.none.fl_str_mv Ibañez Bustos, Romina Valeria
Buccino, Andrea Paola
Messina, S.
Lanza, A. F.
Mauas, Pablo Jacobo David
author Ibañez Bustos, Romina Valeria
author_facet Ibañez Bustos, Romina Valeria
Buccino, Andrea Paola
Messina, S.
Lanza, A. F.
Mauas, Pablo Jacobo David
author_role author
author2 Buccino, Andrea Paola
Messina, S.
Lanza, A. F.
Mauas, Pablo Jacobo David
author2_role author
author
author
author
dc.subject.none.fl_str_mv STARS: ACTIVITY
STARS: LATE-TYPE
TECHNIQUES: SPECTROSCOPIC
topic STARS: ACTIVITY
STARS: LATE-TYPE
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. Recently, new debates about the role of layers of strong shear have emerged in stellar dynamo theory. Further information on the long-term magnetic activity of fully convective stars could help determine whether their underlying dynamo could sustain activity cycles similar to the solar one. Methods. We performed a thorough study of the short- and long-term magnetic activity of the young active dM4 star Gl 729. First, we analyzed long-cadence K2 photometry to characterize its transient events (e.g., flares) and global and surface differential rotation. Then, from the Mount Wilson S-indexes derived from CASLEO spectra and other public observations, we analyzed its long-term activity between 1998 and 2020 with four different time-domain techniques to detect cyclic patterns. Finally, we explored the chromospheric activity at different heights with simultaneous measurements of the Hα and the Na I D indexes, and we analyzed their relations with the S-Index. Results. We found that the cumulative flare frequency follows a power-law distribution with slope ~-0.73 for the range 1032-1034 erg. We obtained Prot = (2.848 ± 0.001) days, and we found no evidence of differential rotation. We also found that this young active star presents a long-term activity cycle with a length of about 4 yr; there is less significant evidence of a shorter cycle of 0.8 yr. The star also shows a broad activity minimum between 1998 and 2004. We found a correlation between the S index, on the one hand, and the Hα the Na I D indexes, on the other hand, although the saturation level of these last two indexes is not observed in the Ca lines. Conclusions. Because the maximum-entropy spot model does not reflect migration between active longitudes, this activity cycle cannot be explained by a solar-type dynamo. It is probably caused by an α2-dynamo.
Fil: Ibañez Bustos, Romina Valeria. 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: 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: Messina, S.. Osservatorio Astrofisico di Catania; Italia
Fil: Lanza, A. F.. Osservatorio Astrofisico di Catania; Italia
Fil: Mauas, Pablo Jacobo David. 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
description Aims. Recently, new debates about the role of layers of strong shear have emerged in stellar dynamo theory. Further information on the long-term magnetic activity of fully convective stars could help determine whether their underlying dynamo could sustain activity cycles similar to the solar one. Methods. We performed a thorough study of the short- and long-term magnetic activity of the young active dM4 star Gl 729. First, we analyzed long-cadence K2 photometry to characterize its transient events (e.g., flares) and global and surface differential rotation. Then, from the Mount Wilson S-indexes derived from CASLEO spectra and other public observations, we analyzed its long-term activity between 1998 and 2020 with four different time-domain techniques to detect cyclic patterns. Finally, we explored the chromospheric activity at different heights with simultaneous measurements of the Hα and the Na I D indexes, and we analyzed their relations with the S-Index. Results. We found that the cumulative flare frequency follows a power-law distribution with slope ~-0.73 for the range 1032-1034 erg. We obtained Prot = (2.848 ± 0.001) days, and we found no evidence of differential rotation. We also found that this young active star presents a long-term activity cycle with a length of about 4 yr; there is less significant evidence of a shorter cycle of 0.8 yr. The star also shows a broad activity minimum between 1998 and 2004. We found a correlation between the S index, on the one hand, and the Hα the Na I D indexes, on the other hand, although the saturation level of these last two indexes is not observed in the Ca lines. Conclusions. Because the maximum-entropy spot model does not reflect migration between active longitudes, this activity cycle cannot be explained by a solar-type dynamo. It is probably caused by an α2-dynamo.
publishDate 2020
dc.date.none.fl_str_mv 2020-11
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/162555
Ibañez Bustos, Romina Valeria; Buccino, Andrea Paola; Messina, S.; Lanza, A. F.; Mauas, Pablo Jacobo David; Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle; EDP Sciences; Astronomy and Astrophysics; 644; 11-2020; 1-14
0004-6361
CONICET Digital
CONICET
url http://hdl.handle.net/11336/162555
identifier_str_mv Ibañez Bustos, Romina Valeria; Buccino, Andrea Paola; Messina, S.; Lanza, A. F.; Mauas, Pablo Jacobo David; Activity-rotation in the dM4 star Gl 729: A possible chromospheric cycle; EDP Sciences; Astronomy and Astrophysics; 644; 11-2020; 1-14
0004-6361
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/10.1051/0004-6361/202039164
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202039164
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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application/pdf
dc.publisher.none.fl_str_mv EDP Sciences
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reponame_str CONICET Digital (CONICET)
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repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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