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PG 1018−047 : the longest period subdwarf B binary

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Deca, J., Marsh, T. R., Østensen, R. H., Morales-Rueda, L., Copperwheat, C. M., Wade, R. A., Stark, M. A., Maxted, P. F. L., Nelemans, G. and Heber, U.. (2012) PG 1018−047 : the longest period subdwarf B binary. Monthly Notices of the Royal Astronomical Society, Vol.421 (No.4). pp. 2798-2808. ISSN 0035-8711

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Official URL: http://dx.doi.org/10.1111/j.1365-2966.2012.20483.x

Abstract

About 50 per cent of all known hot subdwarf B stars (sdBs) reside in close (short-period) binaries, for which common-envelope ejection is the most likely formation mechanism. However, Han et al. predict that the majority of sdBs should form through stable mass transfer leading to long-period binaries. Determining orbital periods for these systems is challenging and while the orbital periods of ∼100 short-period systems have been measured, there are no periods measured above 30 d. As part of a large programme to characterize the orbital periods of sdB binaries and their formation history, we have found that PG 1018−047 has an orbital period of 759.8 ± 5.8 d, easily making it the longest period ever detected for a sdB binary. Exploiting the Balmer lines of the subdwarf primary and the narrow absorption lines of the companion present in the spectra, we derive the radial velocity amplitudes of both stars, and estimate the mass ratio MMS/MsdB= 1.6 ± 0.2. From the combination of visual and infrared photometry, the spectral type of the companion star is determined to be mid-K.

Item Type:

Journal Article

Subjects:

Q Science > QB Astronomy

Divisions:

Faculty of Science > Physics

Library of Congress Subject Headings (LCSH):

Double stars -- Orbits, Double stars -- Evolution, B stars

Journal or Publication Title:

Monthly Notices of the Royal Astronomical Society

Publisher:

Wiley

ISSN:

0035-8711

Official Date:

2012

Dates:

Date	Event
2012	Published

Volume:

Vol.421

Number:

No.4

Page Range:

pp. 2798-2808

Identification Number:

10.1111/j.1365-2966.2012.20483.x

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Restricted or Subscription Access

Funder:

Science and Technology Facilities Council (Great Britain) (STFC), Seventh Framework Programme (European Commission) (FP7), European Research Council (ERC), Katholieke Universiteit te Leuven (1970- ), Particle Physics and Astronomy Research Council (Great Britain) (PPARC), Nederlandse Organisatie voor Wetenschappelijk Onderzoek [Netherlands Organisation for Scientific Research] (NWO), National Science Foundation (U.S.) (NSF)

Grant number:

227224 (ERC), GOA/2008/04 (KUL), 639.042.201 (NWO), AST-0908642 (NSF)

References:

Brown T. M., Ferguson H. C., Davidsen A. F., Dorman B., 1997, ApJ, 482,
685
Brown T. M., Bowers C.W., Kimble R. A., Sweigart A. V., Ferguson H. C.,
2000, ApJ, 532, 308
Charpinet S., Fontaine G., Brassard P., Dorman P., 1996, ApJ, 471, L103
Clausen D., Wade R. A., 2011, ApJ, 733, L42
Copperwheat C. M.,Morales-Rueda L.,Marsh T. R.,Maxted P. F. L., Heber
U., 2011, MNRAS, 410, 1113
Cumming A., Marcy G. W., Butler R. P., 1999, ApJ, 526, 890
Ferguson H. C. et al., 1991, ApJ, 382, L69
Fontaine G., Brassard P., Charpinet S., Green E. M., Chayer P., Randall S.
K., van Grootel V., 2008, in Heber U., Jeffery C. S., Napiwotzki R.,
eds, ASP Conf. Ser. Vol. 392, Hot Subdwarf Stars and Related Objects.
Astron. Soc. Pac., San Francisco, p. 231
Geier S. et al., 2011, A&A, 530, A28
Gilks W. R., Richardson S., Spiegelhalter D., 1995, Markov Chain Monte
Carlo in Practice. Chapman & Hall, London
Green E. M. et al., 2003, ApJ, 583, L31
Green R. F., Schmidt M., Liebert J., 1986, ApJS, 61, 305
Han Z., Podsiadlowski Ph., Maxted P. F. L., Marsh T. R., Ivanova N., 2002,
MNRAS, 336, 449
Han Z., Podsiadlowski Ph., Maxted P. F. L., Marsh T. R., 2003, MNRAS,
341, 669
Heber U., 1986, A&A, 155, 33
Heber U., 2009, ARA&A, 47, 211
Heber U., Hunger K., Jonas G., Kudritzki R. P., 1984, A&A, 130, 119
Heber U., Reid I. N., Werner K., 2000, A&A, 363, 198
Horne K., 1986, PASP, 98, 609
Johnson H. L., 1966, ARA&A, 4, 193
Kilkenny D., Koen C., O’Donoghue D., Stobie R. S., 1997, MNRAS, 285,
640
Kilkenny D.,Koen C., Jeffery J.,Hill C. S., O’Donoghue D., 1999, MNRAS,
310, 1119
Lomb N. R., 1976, Ap&SS, 39, 447
Marsh T. R., 1989, PASP, 101, 1032
Marsh T. R., Robinson E. L., Wood J. H., 1994, MNRAS, 266, 137
Maxted P. F. L., Marsh T. R., Moran C. K. J., 2000, MNRAS, 319,
305
Maxted P. F. L., Heber U., Marsh T. R., North R. C., 2001, MNRAS, 326,
139
Montes D., Mart´ın E. L., Fernand´ez-Figueroa M. J., Cornide M., De Castro
E., 1997, A&AS, 123, 473
Morales-Rueda L., Maxted P. F. L., Marsh T. R., North R. C., Heber U.,
2003, MNRAS, 338, 752
Munari U., Sordo R., Castelli F. Zwitter T., 2005, A&A, 442, 1127
Nelemans G., 2010, Ap&SS, 329, 25
Nelemans G., Verbunt F., Yungelson L. R., Portegies Zwart S. F., 2000,
A&A, 360, 1011
Nelemans G., Yungelson L. R., Portegies Zwart S. F., Verbunt F., 2001,
A&A, 365, 491
PressW. H., Teukolsky S. A., VetterlingW. T., Flannery B. T., 2002, Numerical
Recipes in C: The Art of Scientific Computing. Cambridge Univ.
Press, Cambridge
Ralchenko Y., Kramida A. E., Reader J., NIST ASD Team, 2010, NIST
Atomic SpectraDatabase (ver. 4.0.1).National Institute of Standards and
Technology, Gaithersburg,MD(available at: http://physics.nist.gov/asd)
Saffer R. A., Bergeron P., Koester D., Liebert J., 1994, ApJ, 432, 351
Scargle J. D., 1982, ApJ, 263, 835
Skrutskie M. F. et al., 2006, AJ, 131, 1163
Stark M. A., Wade R. A., 2003, AJ, 126, 1455
Tonry J., Davis M., 1979, AJ, 84, 1511
Turner D. G., 1990, PASP, 102, 1331
Østensen R. H., 2009, Commun. Asteroseismol., 159, 75
Østensen R. H., 2010, Astron. Nachr., 331, 1026