Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-19T18:59:57.355Z Has data issue: false hasContentIssue false
  • English
  • Français

A Radio and Optical Study of the Active Young F Star HR 1817 (=HD 35850)

Published online by Cambridge University Press:  05 March 2013

E. Budding ,
B. D. Carter ,
M. W. Mengel ,
O. B. Slee  and
J.-F. Donati
E. Budding
Affiliation:
Central Institute of Technology, PO Box 40740, Wellington, New Zealand. Carter Observatory, PO Box 2909, Wellington, New Zealand
B. D. Carter
Affiliation:
Centre for Astronomy, Solar Radiation and Climate, Faculty of Sciences, University of Southern Queensland, Toowoomba, Queensland 4350, Australia; carterb@usq.edu.au
M. W. Mengel
Affiliation:
Centre for Astronomy, Solar Radiation and Climate, Faculty of Sciences, University of Southern Queensland, Toowoomba, Queensland 4350, Australia; mengelm@usq.edu.au
O. B. Slee
Affiliation:
Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, Australia; Bruce.Slee@atnf.csiro.au
J.-F. Donati
Affiliation:
Observatoire Midi-Pyrénées, 14 avenue Edouard Belin, F-31400 Toulouse, France; jean-francois.donati@ast.obs-mip.fr
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

This paper presents the results of a multiwavelength observational study of the active young F-type star HR 1817. The star was monitored at 4.80 and 8.64 GHz over 2 × 12 h allocations with the Australia Telescope Compact Array on 8 and 9 December, 2000. The Anglo-Australian Telescope was used for simultaneous optical spectropolarimetry during a 2 h period on 9 December.

The low levels of observed radio emission have characteristics that are similar to those seen in other active stars, and a gyrosynchrotron mechanism is proposed to explain them; this is supported by the relatively low fractions of circular polarisation measured in HR 1817.

Comparison of the emissions from 4.80 and 8.64 GHz shows a very strong cross-correlation peak, indicative of a common origin, although the shift of this peak indicates that 8.64 GHz variations tend to precede those at 4.80 GHz by, typically, ˜20 min.

The optical spectropolarimetry reveals polarisation signals characteristic of surface magnetic fields, with profile changes indicating a complex dynamo-type magnetic topology is present on the star. This result makes HR 1817 the star with the earliest spectral type on which dynamo magnetic fields have been detected directly up to now.

Keywords

stars: activitystars: coronaestars: individual (HR 1817)radio continuum: starstechniques: miscellaneoustechniques: Zeeman Doppler imaging
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 19 , Issue 4 , 2002 , pp. 527 - 533
Copyright
Copyright © Astronomical Society of Australia 2002

References

Budding, E., Burgess, A., Chan, S., & Slee, O. B. 1992, in Surface Inhomogeneities on Late Type Stars, Lecture Notes in Physics 397, ed. P. B. Byrne & D. J. Mullan (Heidelberg: Springer-Verlag), 253 Google Scholar
Budding, E., Jones, K. L., Slee, O. B., & Watson, L. 1999, MNRAS, 305, 966 CrossRefGoogle Scholar
Budding, E., Lim, J., Slee, O. B., & White, S. M. 2002, NewA, 7, 35 CrossRefGoogle Scholar
Collier Cameron, A., & Robinson, R. D. 1989, MNRAS, 238, 657 Google Scholar
Cutispoto, G., Messina, S., & Rodono, M. 2001, A&A, 367, 910 Google Scholar
D'Antona, F., Montalban, J., Kupka, F., & Heiter, U. 2002, ApJ, 564, L93 Google Scholar
Donati, J.-F., Semel, M., Carter, B. D., Rees, D. E., Collier Cameron, A. 1997, MNRAS, 291, 658 CrossRefGoogle Scholar
Dravins, D. 1999, in ASP Conf. Series 185, IAU Colloquium 170, ed. J. B. Hearnshaw & C. D. Scarfe (San Francisco: ASP), 268 Google Scholar
Dulk, G. A. 1985, ARA&A, 23, 169 Google Scholar
Gagné, M., Valenti, J. A., Linksy, J. L., Tagliaferri, G., Covino, S., & Güdel, M. 1999, ApJ, 515, 423 Google Scholar
Jones, K. L., Brown, A., Stewart, R. T., Slee, O. B. 1996, MNRAS, 283, 1331 Google Scholar
Mathioudakis, M., & Mullan, D. J. 1999, A&A, 342, 524 Google Scholar
Manchester, R. 1991, AdSpR, 11, 403 Google Scholar
Mestel, L., & Spruit, H. C. 1987, MNRAS, 226, 57 Google Scholar
Owen, F. N., Jones, T. W., & Gibson, D. M. 1976, ApJ, 210, L27 Google Scholar
Rachford, B. L. 1998, PhD Thesis, University of Wyoming Google Scholar
Sault, R., & Killeen, N. 1996, Multichannel Image Reconstruction, Image Analysis and Display (MIRIAD) Users Guide, ATNF, CSIROGoogle Scholar
Slee, O. B., & Stewart, R. T. 1989, MNRAS, 236, 129 Google Scholar
Slee, O. B., Nelson, G. J., Innis, J. L., Stewart, R. T., Vaughan, A. E., & Wright, A. E. 1986, PASA, 6, 312 Google Scholar
Tagliaferri, G., Covino, S., Fleming, T. A., Gagné, M., Pallavicini, R., Haardt, F., & Uchida, Y. 1997, A&A, 321, 850 Google Scholar
Watson, L. 1999, PhD Thesis, University of Canterbury Google Scholar
Zuckerman, B., Song, I., Bessell, M., & Webb, R. 2001, ApJ, 562, L87 Google Scholar