Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-19T22:46:44.852Z Has data issue: false hasContentIssue false

Stripped red giant cores in eclipsing binary star systems

Published online by Cambridge University Press:  25 February 2014

P.F.L. Maxted
Affiliation:
Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG, UK
U. Heber
Affiliation:
Dr. Karl Remeis-Observatory & ECAP, Sternwartstr. 7, 96049 Bamberg, Germany
B. Smalley
Affiliation:
Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG, UK
T.R. Marsh
Affiliation:
Department of Physics, University of Warwick, Coventry CV4 7AL, UK
Get access

Abstract

Red giant stars can be stripped of their outer layers by stellar collisions or mass transfer in binary star systems such as low mass X-ray binaries. If the star is stripped on or before its first ascent of the red giant branch it will eventually become a very low mass white dwarf composed almost entirely of helium. Very low mass white dwarfs are well known in binary milli-second pulsars and many have recently been found in surveys such as the Sloan Digital Sky Survey, but the precursor phase during which the remnant evolves to higher effective temperature at nearly constant luminosity has rarely been observed. The cooling timescale for very low mass white dwarfs is very uncertain because they are thought to be born with thick hydrogen envelopes which can sustain weak but stable p-p shell burning, but unstable phases of CNO burning (shell flashes) can remove this hydrogen envelope. The predicted number of shell flashes (if any) is dependent on the mass and composition of the star and other details of the models used. In this talk I present new observations of a bright eclipsing binary star recently discovered in the WASP archive in which a stripped red giant is eclipsed by an A-type dwarf star. These observations were used to derive precise masses and radii for both stars and have be used to test the formation scenario outlined above. In addition, I present the main characteristics of 17 new eclipsing binary stars that are also likely to contain the precursors of very low mass white dwarfs.

Type
Research Article
Copyright
© EAS, EDP Sciences, 2014

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agüeros, M.A., Camilo, F., Silvestri, N.M., et al., 2009, ApJ, 697, 283CrossRef
Althaus, L.G., Serenelli, A.M., & Benvenuto, O.G., 2001, MNRAS, 323, 471CrossRef
Bíró, I.B., & Nuspl, J., 2011, MNRAS, 416, 1601CrossRef
Bogdanovic, T., Cheng, R.M., & Amaro-Seoane, P., 2013 [arxiv:1307.6176]
Breton, R.P., Rappaport, S.A., van Kerkwijk, M.H., & Carter, J.A., 2012, ApJ, 748, 115CrossRef
Carter, J.A., Rappaport, S., & Fabrycky, D., 2011, ApJ, 728, 139CrossRef
Chen, X., & Han, Z., 2003, MNRAS, 341, 662CrossRef
Dhillon, V.S., Marsh, T.R., Stevenson, M.J., et al., 2007, MNRAS, 378, 825CrossRef
Driebe, T., Blöcker, T., Schönberner, D., & Herwig, F., 1999, A&A, 350, 89
Driebe, T., Schoenberner, D., Bloecker, T., & Herwig, F., 1998, A&A, 339, 123
Gezari, S., Chornock, R., Rest, A., et al., 2012, Nature, 485, 217CrossRef
Giannone, P., & Giannuzzi, M.A., 1970, A&A, 6, 309PubMed
Heber, U., Edelmann, H., Lisker, T., & Napiwotzki, R., 2003, A&A, 411, L477
Iben, Jr., I., & Livio, M., 1993, PASP, 105, 1373CrossRef
Justham, S., Wolf, C., Podsiadlowski, P., & Han, Z., 2009, A&A, 493, 1081
Kaluzny, J., Rucinski, S.M., Thompson, I.B., Pych, W., & Krzeminski, W., 2007, AJ, 133, 2457CrossRef
Kilic, M., Brown, W.R., Allen de Prieto, C., et al., 2012, ApJ, 751, 141CrossRef
Kleinman, S.J., Kepler, S.O., Koester, D., et al., 2013, ApJS, 204, 5CrossRef
Knigge, C., Dieball, A., Maíz Apellániz, J., et al., 2008, ApJ, 683, 1006CrossRef
Lorimer, D.R., 2008, Living Rev. Relativity, 11, 8CrossRef
Marsh, T.R., Dhillon, V.S., & Duck, S.R., 1995, MNRAS, 275, 828CrossRef
Maxted, P.F.L., Anderson, D.R., Burleigh, M.R., et al., 2011, MNRAS, 418, 1156CrossRef
Maxted, P.F.L., Bloemen, S., Heber, U., et al., 2013a, MNRAS.tmp.2695
Maxted, P.F.L., Serenelli, A.M., Miglio, A., et al., 2013b, Nature, 498, 463CrossRef
Nelson, C.A., & Eggleton, P.P., 2001, ApJ, 552, 664CrossRef
Nelson, L.A., Dubeau, E., & MacCannell, K.A., 2004, ApJ, 616, 1124CrossRef
O'Toole, S.J., Napiwotzki, R., Heber, U., et al., 2006, Baltic Astron., 15, 61
Pietrzyński, G., Thompson, I.B., Gieren, W., et al., 2012, Nature, 484, 75CrossRef
Pollacco, D.L., Skillen, I., Collier Cameron, A., et al., 2006, PASP, 118, 1407CrossRef
Refsdal, S., & Weigert, A., 1969, A&A, 1, 167
Rowe, J.F., Borucki, W.J., Koch, D., et al., 2010, ApJ, 713, L150CrossRef
Simon, K.P., & Sturm, E., 1994, A&A, 281, 286PubMed
van Kerkwijk, M.H., Rappaport, S.A., Breton, R.P., et al., 2010, ApJ, 715, 51CrossRef
Webbink, R.F., 1975, MNRAS, 171, 555CrossRef
Willems, B., & Kolb, U., 2004, A&A, 419, 1057