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Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale

Delorme, P.; Cameron, A. C.; Hebb, L.; Rostron, J. ; Lister, T. A.; Norton, A. J.; Pollacco, D. and West, R. G. (2011). Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale. In: 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, 28 August - 02 September 2010, University of Washington, Seattle, Washington.

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We present the results of photometric surveys for stellar rotation in the Hyades and in Praesepe, using data obtained as part of the SuperWASP exoplanetary transit-search programme. We determined accurate rotation periods for more than 120 sources whose cluster membership was confirmed by common proper motion and colour-magnitude fits to the clusters' isochrones. This allowed us to determine the effect of magnetic braking on a wide range of spectral types for expected ages of ~600 Myr for the Hyades and Praesepe. Both clusters show a tight and nearly linear relation between J–Ks colour and rotation period in the F, G and K spectral range. This confirms that loss of angular momentum was significant enough that stars with strongly different initial rotation rates have converged to the same rotation period for a given mass, by the age of Hyades and Praesepe. In the case of the Hyades our colour-period sequence extends well into the M dwarf regime and shows a steep increase in the scatter of the colour-period relation, with identification of numerous rapid rotators from ~0.5M down to the lowest masses probed by our survey (~0.25M). This provides crucial constraints on the rotational braking timescales and further clears the way to use gyrochronology as an accurate age measurement tool for main-sequence stars.

Item Type: Conference or Workshop Item
Copyright Holders: 2011 Astronomical Society of the Pacific
Extra Information: 16th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun
Ed. Christopher M. Johns-Krull, Matthew K. Browning, and Andrew A. West,
28 August – 2 September, 2010 Seattle, Washington
Print ISBN: 978-1-58381-776-6
E-book ISBN: 978-1-58381-777-3
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Related URLs:
Item ID: 33635
Depositing User: Andrew Norton
Date Deposited: 10 May 2012 09:52
Last Modified: 23 Dec 2016 02:32
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