Period and period change measurements for 143 SuperWASP eclipsing binary candidates near the short-period limit and discovery of a doubly eclipsing quadruple system^⋆

¹ Department of Physical SciencesThe Open University, Walton Hall, Milton Keynes MK7 6AA, UK
e-mail: Marcus.Lohr@open.ac.uk
² Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
³ Astrophysics Research Centre, School of Mathematics & Physics, Queen’s University, University Road, Belfast BT7 1NN, UK
⁴ Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK

Received: 15 October 2012
Accepted: 18 November 2012

Abstract

Building on previous work, a new search of the SuperWASP archive was carried out to identify eclipsing binary systems near the short-period limit. 143 candidate objects were detected with orbital periods between 16 000 and 20 000 s, of which 97 are new discoveries. Period changes significant at 1σ or more were detected in 74 of these objects, and in 38 the changes were significant at 3σ or more. The significant period changes observed followed an approximately normal distribution with a half-width at half-maximum of  ~0.1 s yr^-1. There was no apparent relationship between period length and magnitude or direction of period change. Amongst several interesting individual objects studied, 1SWASP J093010.78+533859.5 is presented as a new doubly eclipsing quadruple system, consisting of a contact binary with a 19 674.575 s period and an Algol-type binary with a 112 799.109 s period, separated by 66.1 AU, being the sixth known system of this type.