Magnetic fields and differential rotation on the pre-main sequence - II. The early-G star HD 141943 - coronal magnetic field, Hα emission and differential rotation
Article
Article Title | Magnetic fields and differential rotation on the pre-main sequence - II. The early-G star HD 141943 - coronal magnetic field, Hα emission and differential rotation |
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ERA Journal ID | 1074 |
Article Category | Article |
Authors | Marsden, S. C. (Author), Jardine, M. M. (Author), Ramirez Velez, J. C. (Author), Alecian, E. (Author), Brown, C. J. (Author), Carter, B. D. (Author), Donati, J.-F. (Author), Dunstone, N. (Author), Hart, R. (Author), Semel, M. (Author) and Waite, I. A. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 413 (3), pp. 1939-1948 |
Number of Pages | 10 |
Year | 2011 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1111/j.1365-2966.2011.18272.x |
Web Address (URL) | https://academic.oup.com/mnras/article/413/3/1939/966302 |
Abstract | Spectropolarimetric observations of the pre-main sequence early-G star HD 141943 were made at three observing epochs (2007, 2009 and 2010). The observations were made using the 3.9-m Anglo-Australian Telescope with the UCLES echelle spectrograph and the SEMPOL spectropolarimeter visitor instrument. The brightness and surface magnetic field topologies (given in Paper I) were used to determine the star's surface differential rotation and reconstruct the coronal magnetic field of the star. The coronal magnetic field at the three epochs shows on the largest scales that the field structure is dominated by the dipole component with possible evidence for the tilt of the dipole axis shifting between observations. We find very high levels of differential rotation on HD 141943 (~8 times the solar value for the magnetic features and ~5 times solar for the brightness features), similar to that evidenced by another young early-G star, HD 171488. These results indicate that a significant increase in the level of differential rotation occurs for young stars around a spectral type of early-G. We also find for the 2010 observations that there is a large difference in the differential rotation measured from the brightness and magnetic features, similar to that seen on early-K stars, but with the difference being much larger. We find only tentative evidence for temporal evolution in the differential rotation of HD 141943. © 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS. |
Keywords | Magnetic fields; Stars: activity; Stars: imaging; Stars: individual: HD 141943 |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
510203. Nonlinear optics and spectroscopy | |
490402. Algebraic and differential geometry | |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2011 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | James Cook University |
University of St Andrews, United Kingdom | |
Paris Sciences and Letters University, France | |
Laboratory of Space Science and Astrophysical Instrumentation, France | |
Department of Biological and Physical Sciences | |
Institute for Research in Astrophysics and Planetology, France | |
Office of Research | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q1183/magnetic-fields-and-differential-rotation-on-the-pre-main-sequence-ii-the-early-g-star-hd-141943-coronal-magnetic-field-h-emission-and-differential-rotation
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