A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771
Received??; accepted?? Aims. We investigate the long-term evolution of the large-scale photospheric magnetic field geometry of the solar-type star HD 190771. With fundamental parameters very close to the Sun’s except a shorter rotation period of 8.8 d, HD 190771 provides us with a first insight into...
Main Authors: | , , , , , , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
2009
|
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.246.9824 http://arxiv.org/pdf/0909.2200v1.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.246.9824 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.246.9824 2023-05-15T18:50:47+02:00 A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 P. Petit B. Dintrans A. Morgenthaler V. Van Grootel J. Morin J. Lanoux M. Aurière The Pennsylvania State University CiteSeerX Archives 2009 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.246.9824 http://arxiv.org/pdf/0909.2200v1.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.246.9824 http://arxiv.org/pdf/0909.2200v1.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/0909.2200v1.pdf text 2009 ftciteseerx 2016-01-07T19:30:28Z Received??; accepted?? Aims. We investigate the long-term evolution of the large-scale photospheric magnetic field geometry of the solar-type star HD 190771. With fundamental parameters very close to the Sun’s except a shorter rotation period of 8.8 d, HD 190771 provides us with a first insight into the specific impact of the rotation rate in the dynamo generation of magnetic fields in 1 M ⊙ stars. Methods. We use circularly polarized, high-resolution spectra obtained with the NARVAL spectropolarimeter (Observatoire du Pic du Midi, France) and compute cross-correlation line profiles with high signal-to-noise ratio in order to detect polarized Zeeman signatures. From three phase-resolved data sets collected during the summers of 2007, 2008 and 2009, we model the large-scale photospheric magnetic field of the star by means of Zeeman-Doppler imaging and follow its temporal evolution. Results. The comparison of the magnetic maps reveals a polarity reversal of the axisymmetric component of the large-scale magnetic field between 2007 and 2008, this evolution being observed both in the poloidal and toroidal magnetic components. Between 2008 and 2009, another type of global evolution occurs, with a sharply decreased fraction of magnetic energy stored in the toroidal component. These changes are not accompanied by a significant evolution of the total photospheric magnetic energy. Using our spectra to perform Text narval narval Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
description |
Received??; accepted?? Aims. We investigate the long-term evolution of the large-scale photospheric magnetic field geometry of the solar-type star HD 190771. With fundamental parameters very close to the Sun’s except a shorter rotation period of 8.8 d, HD 190771 provides us with a first insight into the specific impact of the rotation rate in the dynamo generation of magnetic fields in 1 M ⊙ stars. Methods. We use circularly polarized, high-resolution spectra obtained with the NARVAL spectropolarimeter (Observatoire du Pic du Midi, France) and compute cross-correlation line profiles with high signal-to-noise ratio in order to detect polarized Zeeman signatures. From three phase-resolved data sets collected during the summers of 2007, 2008 and 2009, we model the large-scale photospheric magnetic field of the star by means of Zeeman-Doppler imaging and follow its temporal evolution. Results. The comparison of the magnetic maps reveals a polarity reversal of the axisymmetric component of the large-scale magnetic field between 2007 and 2008, this evolution being observed both in the poloidal and toroidal magnetic components. Between 2008 and 2009, another type of global evolution occurs, with a sharply decreased fraction of magnetic energy stored in the toroidal component. These changes are not accompanied by a significant evolution of the total photospheric magnetic energy. Using our spectra to perform |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
P. Petit B. Dintrans A. Morgenthaler V. Van Grootel J. Morin J. Lanoux M. Aurière |
spellingShingle |
P. Petit B. Dintrans A. Morgenthaler V. Van Grootel J. Morin J. Lanoux M. Aurière A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
author_facet |
P. Petit B. Dintrans A. Morgenthaler V. Van Grootel J. Morin J. Lanoux M. Aurière |
author_sort |
P. Petit |
title |
A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
title_short |
A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
title_full |
A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
title_fullStr |
A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
title_full_unstemmed |
A polarity reversal in the large-scale magnetic field of the fast-rotating Sun HD 190771 |
title_sort |
polarity reversal in the large-scale magnetic field of the fast-rotating sun hd 190771 |
publishDate |
2009 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.246.9824 http://arxiv.org/pdf/0909.2200v1.pdf |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
http://arxiv.org/pdf/0909.2200v1.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.246.9824 http://arxiv.org/pdf/0909.2200v1.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766244544077103104 |