A search for close binary systems in the SALT survey of hydrogen-deficient stars using TESS

Snowdon EJ, Jeffery CS, Schlagenhauf S, Dorsch M (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Book Volume: 537

Pages Range: 2079-2089

Journal Issue: 2

DOI: 10.1093/mnras/staf152

Abstract

The TESS periodograms of the SALT survey catalogue of hydrogen-deficient stars were searched for evidence of short-period variability. Periodic light-curve variations were identified in 16 stars out of 153 catalogue objects, of which 10 were false positives. From the remaining 6 identified variables, Ton S 415 is a known close binary system and the sixth close binary containing a hydrogen-deficient hot subdwarf. Radial velocity and SED analyses ruled out the remaining 5 as close binary systems; the causes of their variability remain uncertain. With one or more K-type companions, BPS CS 22956-0094 may be a wide binary or triple. From this SALT + TESS sample, the fraction of close binaries stands at 1/29 ≈ 3.5 per cent for intermediate helium hot subdwarfs and 0/124 = 0 per cent for extreme helium subdwarfs.

Involved external institutions

Armagh Observatory GB United Kingdom (GB) Universität Potsdam DE Germany (DE)

How to cite

APA:

Snowdon, E.J., Jeffery, C.S., Schlagenhauf, S., & Dorsch, M. (2025). A search for close binary systems in the SALT survey of hydrogen-deficient stars using TESS. Monthly Notices of the Royal Astronomical Society, 537(2), 2079-2089. https://doi.org/10.1093/mnras/staf152

MLA:

Snowdon, E. J., et al. "A search for close binary systems in the SALT survey of hydrogen-deficient stars using TESS." Monthly Notices of the Royal Astronomical Society 537.2 (2025): 2079-2089.

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