Magnetic cycles of the planet-hosting star τ Bootis
We have obtained new spectropolarimetric observations of the planet-hosting star tau Bootis, using the ESPaDOnS and NARVAL spectropolarimeters at the Canada-France-Hawaii Telescope (CFHT) and Telescope Bernard Lyot (TBL). With this data set, we are able to confirm the presence of a magnetic field at...
Published in: | Monthly Notices of the Royal Astronomical Society |
---|---|
Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2008
|
Subjects: | |
Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/magnetic-cycles-of-the-planethosting-star--bootis(2d84e623-6082-433a-876e-16dfeebac048).html https://doi.org/10.1111/j.1365-2966.2008.12946.x http://www.scopus.com/inward/record.url?scp=41649115652&partnerID=8YFLogxK |
id |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/2d84e623-6082-433a-876e-16dfeebac048 |
---|---|
record_format |
openpolar |
spelling |
ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/2d84e623-6082-433a-876e-16dfeebac048 2023-05-15T18:50:52+02:00 Magnetic cycles of the planet-hosting star τ Bootis Donati, J. -F. Moutou, C. Fares, R. Bohlender, D. Catala, C. Deleuil, M. Shkolnik, E. Cameron, Andrew Collier Jardine, Moira Mary Walker, G. A. H. 2008-04-11 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/magnetic-cycles-of-the-planethosting-star--bootis(2d84e623-6082-433a-876e-16dfeebac048).html https://doi.org/10.1111/j.1365-2966.2008.12946.x http://www.scopus.com/inward/record.url?scp=41649115652&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Donati , J -F , Moutou , C , Fares , R , Bohlender , D , Catala , C , Deleuil , M , Shkolnik , E , Cameron , A C , Jardine , M M & Walker , G A H 2008 , ' Magnetic cycles of the planet-hosting star τ Bootis ' , Monthly Notices of the Royal Astronomical Society , vol. 385 , no. 3 , pp. 1179-1185 . https://doi.org/10.1111/j.1365-2966.2008.12946.x stars : activity stars : imaging stars : individual : tau Boo stars : magnetic fields techniques : polarimetric planetary systems DIFFERENTIAL ROTATION GIANT PLANETS ACTIVE STARS SPECTROPOLARIMETRIC OBSERVATIONS CHROMOSPHERIC ACTIVITY 51 PEGASI FIELD article 2008 ftunstandrewcris https://doi.org/10.1111/j.1365-2966.2008.12946.x 2022-10-13T15:25:21Z We have obtained new spectropolarimetric observations of the planet-hosting star tau Bootis, using the ESPaDOnS and NARVAL spectropolarimeters at the Canada-France-Hawaii Telescope (CFHT) and Telescope Bernard Lyot (TBL). With this data set, we are able to confirm the presence of a magnetic field at the surface of tau Boo and map its large-scale structure over the whole star. The large-scale magnetic field is found to be fairly complex, with a strength of up to 10 G; it features a dominant poloidal field and a small toroidal component, the poloidal component being significantly more complex than a dipole. The overall polarity of the magnetic field has reversed with respect to our previous observation (obtained a year before), strongly suggesting that tau Boo is undergoing magnetic cycles similar to those of the Sun. This is the first time that a global magnetic polarity switch is observed in a star other than the Sun; given the infrequent occurrence of such events in the Sun, we speculate that the magnetic cycle period of tau Boo is much shorter than that of the Sun. Our new data also allow us to confirm the presence of differential rotation, both from the shape of the line profiles and the latitudinal shearing that the magnetic structure is undergoing. The differential rotation surface shear that tau Boo experiences is found to be 6 to 10 times larger than that of the Sun, in good agreement with recent claims that differential rotation is strongest in stars with shallow convective zones. We propose that the short-magnetic cycle period is due to the strong level of differential rotation. With a rotation period of 3.0 and 3.9 d at the equator and pole, respectively, tau Boo appears as the first planet-hosting star whose rotation (at intermediate latitudes) is synchronized with the orbital motion of its giant planet (period 3.3 d). Assuming that this synchronization is not coincidental, it suggests that the tidal effects induced by the giant planet can be strong enough to force the thin convective envelope (though ... Article in Journal/Newspaper narval narval University of St Andrews: Research Portal Canada Monthly Notices of the Royal Astronomical Society 385 3 1179 1185 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
stars : activity stars : imaging stars : individual : tau Boo stars : magnetic fields techniques : polarimetric planetary systems DIFFERENTIAL ROTATION GIANT PLANETS ACTIVE STARS SPECTROPOLARIMETRIC OBSERVATIONS CHROMOSPHERIC ACTIVITY 51 PEGASI FIELD |
spellingShingle |
stars : activity stars : imaging stars : individual : tau Boo stars : magnetic fields techniques : polarimetric planetary systems DIFFERENTIAL ROTATION GIANT PLANETS ACTIVE STARS SPECTROPOLARIMETRIC OBSERVATIONS CHROMOSPHERIC ACTIVITY 51 PEGASI FIELD Donati, J. -F. Moutou, C. Fares, R. Bohlender, D. Catala, C. Deleuil, M. Shkolnik, E. Cameron, Andrew Collier Jardine, Moira Mary Walker, G. A. H. Magnetic cycles of the planet-hosting star τ Bootis |
topic_facet |
stars : activity stars : imaging stars : individual : tau Boo stars : magnetic fields techniques : polarimetric planetary systems DIFFERENTIAL ROTATION GIANT PLANETS ACTIVE STARS SPECTROPOLARIMETRIC OBSERVATIONS CHROMOSPHERIC ACTIVITY 51 PEGASI FIELD |
description |
We have obtained new spectropolarimetric observations of the planet-hosting star tau Bootis, using the ESPaDOnS and NARVAL spectropolarimeters at the Canada-France-Hawaii Telescope (CFHT) and Telescope Bernard Lyot (TBL). With this data set, we are able to confirm the presence of a magnetic field at the surface of tau Boo and map its large-scale structure over the whole star. The large-scale magnetic field is found to be fairly complex, with a strength of up to 10 G; it features a dominant poloidal field and a small toroidal component, the poloidal component being significantly more complex than a dipole. The overall polarity of the magnetic field has reversed with respect to our previous observation (obtained a year before), strongly suggesting that tau Boo is undergoing magnetic cycles similar to those of the Sun. This is the first time that a global magnetic polarity switch is observed in a star other than the Sun; given the infrequent occurrence of such events in the Sun, we speculate that the magnetic cycle period of tau Boo is much shorter than that of the Sun. Our new data also allow us to confirm the presence of differential rotation, both from the shape of the line profiles and the latitudinal shearing that the magnetic structure is undergoing. The differential rotation surface shear that tau Boo experiences is found to be 6 to 10 times larger than that of the Sun, in good agreement with recent claims that differential rotation is strongest in stars with shallow convective zones. We propose that the short-magnetic cycle period is due to the strong level of differential rotation. With a rotation period of 3.0 and 3.9 d at the equator and pole, respectively, tau Boo appears as the first planet-hosting star whose rotation (at intermediate latitudes) is synchronized with the orbital motion of its giant planet (period 3.3 d). Assuming that this synchronization is not coincidental, it suggests that the tidal effects induced by the giant planet can be strong enough to force the thin convective envelope (though ... |
format |
Article in Journal/Newspaper |
author |
Donati, J. -F. Moutou, C. Fares, R. Bohlender, D. Catala, C. Deleuil, M. Shkolnik, E. Cameron, Andrew Collier Jardine, Moira Mary Walker, G. A. H. |
author_facet |
Donati, J. -F. Moutou, C. Fares, R. Bohlender, D. Catala, C. Deleuil, M. Shkolnik, E. Cameron, Andrew Collier Jardine, Moira Mary Walker, G. A. H. |
author_sort |
Donati, J. -F. |
title |
Magnetic cycles of the planet-hosting star τ Bootis |
title_short |
Magnetic cycles of the planet-hosting star τ Bootis |
title_full |
Magnetic cycles of the planet-hosting star τ Bootis |
title_fullStr |
Magnetic cycles of the planet-hosting star τ Bootis |
title_full_unstemmed |
Magnetic cycles of the planet-hosting star τ Bootis |
title_sort |
magnetic cycles of the planet-hosting star τ bootis |
publishDate |
2008 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/magnetic-cycles-of-the-planethosting-star--bootis(2d84e623-6082-433a-876e-16dfeebac048).html https://doi.org/10.1111/j.1365-2966.2008.12946.x http://www.scopus.com/inward/record.url?scp=41649115652&partnerID=8YFLogxK |
geographic |
Canada |
geographic_facet |
Canada |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
Donati , J -F , Moutou , C , Fares , R , Bohlender , D , Catala , C , Deleuil , M , Shkolnik , E , Cameron , A C , Jardine , M M & Walker , G A H 2008 , ' Magnetic cycles of the planet-hosting star τ Bootis ' , Monthly Notices of the Royal Astronomical Society , vol. 385 , no. 3 , pp. 1179-1185 . https://doi.org/10.1111/j.1365-2966.2008.12946.x |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1111/j.1365-2966.2008.12946.x |
container_title |
Monthly Notices of the Royal Astronomical Society |
container_volume |
385 |
container_issue |
3 |
container_start_page |
1179 |
op_container_end_page |
1185 |
_version_ |
1766244630421045248 |