TIC 378898110: A bright, short-period AM CVn binary in TESS

Authors

• Andrzej S. Baran, Missouri State UniversityFollow
• Matthew J Green, Max Planck Institute for Astronomy;Tel Aviv University;Faculty of Science, Engineering and Medicine
• Hermes, College of Arts & Sciences
• Brad N. Barlow, High Point University;College of Arts and Sciences
• Marsh, Faculty of Science, Engineering and Medicine
• Ingrid Pelisoli, Faculty of Science, Engineering and Medicine
• Boris T. Gänsicke, Faculty of Science, Engineering and Medicine
• Ben C. Kaiser, College of Arts and Sciences
• Alejandra Romero, Universidade Federal do Rio Grande do Sul
• Larissa Antunes Amaral, Universidade Federal do Rio Grande do Sul;Universidad de Valparaiso
• Kyle Corcoran, University of Virginia
• Dirk Grupe, Northern Kentucky University
• Mark R. Kennedy, University College Cork;The University of Manchester
• Kepler, Universidade Federal do Rio Grande do Sul
• James Munday, Faculty of Science, Engineering and Medicine;Isaac Newton Group

Abstract

AM CVn-type systems are ultracompact, helium-accreting binary systems that are evolutionarily linked to the progenitors of thermonuclear supernovae and are expected to be strong Galactic sources of gravitational waves detectable to upcoming space-based interferometers. AM CVn binaries with orbital periods ?20-23 min exist in a constant high state with a permanently ionized accretion disc. We present the discovery of TIC 378898110, a bright (G = 14.3 mag), nearby (309.3 ± 1.8 pc), high-state AM CVn binary discovered in TESS two-minute-cadence photometry. At optical wavelengths, this is the third-brightest AM CVn binary known. The photometry of the system shows a 23.07172(6) min periodicity, which is likely to be the 'superhump' period and implies an orbital period in the range 22-23 min. There is no detectable spectroscopic variability. The system underwent an unusual, year-long brightening event during which the dominant photometric period changed to a shorter period (constrained to 20.5 ± 2.0 min), which we suggest may be evidence for the onset of disc-edge eclipses. The estimated mass transfer rate,, is unusually high and may suggest a high-mass or thermally inflated donor. The binary is detected as an X-ray source, with a flux of erg cm^-2 s^-1 in the 0.3-10 keV range. TIC 378898110 is the shortest-period binary system discovered with TESS, and its large predicted gravitational-wave amplitude makes it a compelling verification binary for future space-based gravitational wave detectors.

Department(s)

Physics, Astronomy, and Materials Science

Document Type

Article

DOI

10.1093/mnras/stad3412

Keywords

binaries: close, novae, cataclysmic variables, stars: dwarf novae, stars: individual: TIC 378898110, white dwarfs

Publication Date

1-1-2024

Recommended Citation

Baran, Andrzej S.; Green, Matthew J; Hermes; Barlow, Brad N.; Marsh; Pelisoli, Ingrid; Gänsicke, Boris T.; Kaiser, Ben C.; Romero, Alejandra; Amaral, Larissa Antunes; Corcoran, Kyle; Grupe, Dirk; Kennedy, Mark R.; Kepler; and Munday, James, "TIC 378898110: A bright, short-period AM CVn binary in TESS" (2024). Faculty Scholarship. 512.
https://bearworks.missouristate.edu/articles00/512

Journal Title

Monthly Notices of the Royal Astronomical Society