Magnetic fields and differential rotation on the pre-main sequence - III. The early-G star HD 106506

Waite, I. A. and Marsden, S. C. and Carter, B. D. and Hart, R. and Donati, J. -F. and Ramirez Velez, J. C. and Semel, M. and Dunstone, N. (2011) Magnetic fields and differential rotation on the pre-main sequence - III. The early-G star HD 106506. Monthly Notices of the Royal Astronomical Society, 413 (3). pp. 1949-1960. ISSN 0035-8711

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Abstract

We present the photometry and spectropolarimetry of the pre-main-sequence star HD 106506. A photometric rotational period of ˜1.416 ± 0.133 d has been derived using observations at Mount Kent Observatory (MKO). Spectropolarimetric data obtained with the 3.9-m Anglo-Australian Telescope (AAT) were used to derive spot occupancy and magnetic maps of the star through the technique of Zeeman Doppler imaging (ZDI). The resulting brightness maps indicate that HD 106506 displays photospheric spots at all latitudes including a predominant polar spot. Azimuthal and radial magnetic images of this star have been derived, and a significant azimuthal magnetic field is indicated, in line with other active young stars. A solar-like differential rotation law was incorporated into the imaging process. Using Stokes I information the equatorial rotation rate, Ωeq, was found to be 4.54 ± 0.01 rad d-1, with a photospheric shear δΩ of 0.21+0.02-0.03 rad d-1. This equates to an equatorial rotation period of ˜1.39 ± 0.01 d, with the equatorial region lapping the poles every ˜ 30+5-3 d. Using the magnetic features, the equatorial rotation rate, Ωeq, was found to be 4.51 ± 0.01 rad d-1, with a photospheric shear δΩ of 0.24 ± 0.03 rad d-1. This differential rotation is approximately four times that observed on the Sun.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Authors retain copyright over content; Publisher retains copyright over presentation. Author version made available.
Depositing User: Dr Brad Carter
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 24 Mar 2012 11:17
Last Modified: 26 Aug 2014 21:42
Uncontrolled Keywords: profiles; activity; stars; Zeeman Doppler imaging; solar-type stars; HD106506; magnetic fields; spots
Fields of Research (FOR2008): 01 Mathematical Sciences > 0103 Numerical and Computational Mathematics > 010302 Numerical Solution of Differential and Integral Equations
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
02 Physical Sciences > 0204 Condensed Matter Physics > 020402 Condensed Matter Imaging
Socio-Economic Objective (SEO2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
Identification Number or DOI: doi: 10.1111/j.1365-2966.2011.18366.x
URI: http://eprints.usq.edu.au/id/eprint/20476

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