EL CVn-type binaries - discovery of 17 helium white dwarf precursors in bright eclipsing binary star systems
View/ Open
Date
11/01/2014Author
Grant ID
ST/J001651/1
PP/F000065/1
Keywords
Metadata
Show full item recordAbstract
The star 1SWASP J024743.37-251549.2 was recently discovered to be a binary star in which an A-type dwarf star eclipses the remnant of a disrupted red giant star (WASP 0247-25 B). The remnant is in a rarely observed state evolving to higher effective temperatures at nearly constant luminosity prior to becoming a very low mass white dwarf composed almost entirely of helium, i.e. it is a pre-helium white dwarf (pre-He-WD). We have used the photometric database from the Wide Angle Search for Planets (WASP) to find 17 eclipsing binary stars with orbital periods P = 0.7-2.2 d with similar light curves to 1SWASP J024743.37-251549.2. The only star in this group previously identified as a variable star is the brightest one, EL CVn, which we adopt as the prototype for this class of eclipsing binary star. The characteristic light curves of EL CVn-type stars show a total eclipse by an A-type dwarf star of a smaller, hotter star and a secondary eclipse of comparable depth to the primary eclipse. We have used new spectroscopic observations for six of these systems to confirm that the companions to the A-type stars in these binaries have very low masses (≈0.2MΘ). This includes the companion to EL CVn which was not previously known to be a pre-He-WD. EL CVn-type binary star systems will enable us to study the formation of very low mass white dwarfs in great detail, particularly in those cases where the pre-He-WD star shows non-radial pulsations similar to those recently discovered in WASP0247-25 B.
Citation
Maxted , P F L , Bloemen , S , Heber , U , Geier , S , Wheatley , P J , Marsh , T R , Breedt , E , Sebastian , D , Faillace , G , Owen , C , Pulley , D , Smith , D , Kolb , U , Haswell , C A , Southworth , J , Anderson , D R , Smalley , B , Cameron , A C , Hebb , L , Simpson , E K , West , R G , Bochinski , J , Busuttil , R & Hadigal , S 2014 , ' EL CVn-type binaries - discovery of 17 helium white dwarf precursors in bright eclipsing binary star systems ' , Monthly Notices of the Royal Astronomical Society , vol. 437 , no. 2 , pp. 1681-1697 . https://doi.org/10.1093/mnras/stt2007
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Description
This work was supported by funding from the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement no 227224 (PROSPERITY), as well as from the Science and Technology Facilities Council (grant numbers ST/I001719/1, ST/J001384/1)Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Related items
Showing items related by title, author, creator and subject.
-
Period and amplitude variations in post-common-envelope eclipsing binaries observed with SuperWASP
Lohr, M.E.; Norton, A.J.; Anderson, D.R.; Collier Cameron, A.; Faedi, F.; Haswell, C.A.; Hellier, C.; Hodgkin, S.T.; Horne, K.; Kolb, U.C.; Maxted, P.F.L.; Pollacco, D.; Skillen, I.; Smalley, B.; West, R.G.; Wheatley, P.J. (2014-06-25) - Journal articlePeriod or amplitude variations in eclipsing binaries may reveal the presence of additional massive bodies in the system, such as circumbinary planets. Here, we have studied twelve previously-known eclipsing post-common-envelope ... -
The EBLM project : III. A Saturn-size low-mass star at the hydrogen-burning limit
Von Boetticher, Alexander; Triaud, Amaury H.M.J.; Queloz, DIdier; Gill, Sam; Lendl, Monika; Delrez, Laetitia; Anderson, David R.; Cameron, Andrew Collier; Faedi, Francesca; Gillon, Michaël; Chew, Yilen Gómez Maqueo; Hebb, Leslie; Hellier, Coel; Jehin, Emmanuël; Maxted, Pierre F.L.; Martin, David V.; Pepe, Francesco; Pollacco, Don; Ségransan, Damien; Smalley, Barry; Udry, Stéphane; West, Richard (2017-08-01) - Journal articleWe report the discovery of an eclipsing binary system with mass-ratio q ∼ 0.07. After identifying a periodic photometric signal received by WASP, we obtained CORALIE spectroscopic radial velocities and follow-up light ... -
The EBLM Project. V. Physical properties of ten fully convective, very-low-mass stars
von Boetticher, Alexander; Triaud, Amaury H. M. J.; Queloz, Didier; Gill, Sam; Maxted, Pierre F. L.; Almleaky, Yaseen; Anderson, David R.; Bouchy, Francois; Burdanov, Artem; Cameron, Andrew Collier; Delrez, Laetitia; Ducrot, Elsa; Faedi, Francesca; Gillon, Michaël; Chew, Yilen Gómez Maqueo; Hebb, Leslie; Hellier, Coel; Jehin, Emmanuël; Lendl, Monika; Marmier, Maxime; Martin, David V.; McCormac, James; Pepe, Francesco; Pollacco, Don; Ségransan, Damien; Smalley, Barry; Thompson, Samantha; Turner, Oliver; Udry, Stéphane; Grootel, Valérie Van; West, Richard (2019-06-04) - Journal articleMeasurements of the physical properties of stars at the lower end of the main sequence are scarce. In this context we report masses, radii and surface gravities of ten very-low-mass stars in eclipsing binary systems, with ...