SCYON Abstract

Received on December 10 2009

Explaining the Praesepe blue straggler HD 73666

Authors	L. Fossati (^1,2), S. Mochnacki (³), J. Landstreet (⁴), and W. Weiss (¹)
Affiliation	(¹) Institut für Astronomie, Universität Wien, Türkenschanzstrasse 17, 1180 Wien, Austria (²) Department of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA, UK (³) Department of Astronomy & Astrophysics, University of Toronto, 50 St.George St, Rm.101, Toronto, ON, Canada M5S 3H4 (⁴) Department of Physics & Astronomy, University of Western Ontario, London, ON, Canada N6A 3K7
Accepted by	Astronomy & Astrophysics
Contact	l.fossati@open.ac.uk
URL
Links	Praesepe

Abstract

The blue straggler phenomenon is not yet well explained by current theory, although evolutionary models of star clusters require a good knowledge of it. We attempt to develop a formation scenario for HD 73666, a blue straggler member of the Praesepe cluster. We compile the known physical properties of HD 73666 found in the literature, focusing in particular on possible binarity and the abundance pattern. HD 73666 appears to be slowly rotating, have no detectable magnetic field, and have normal abundances, thereby excluding close binary evolution and mass transfer processes. There is no evidence of a hot radiation source. With the use of theoretical results on blue straggler formation present in literature, we are able to conclude that HD 73666 was probably formed by physical collision involving at least one binary system, between 5 and 350 Myr (50 Myr if the star is an intrinsic slow rotator) ago.