Pulse Timing Discovery of a Three-day Companion to the Hot Subdwarf BPM 36430
- Hot subdwarf B stars are core-helium-burning objects that have undergone envelope stripping, likely by a binary companion. Using high-speed photometry from the Transiting Exoplanet Survey Satellite, we have discovered the hot subdwarf BPM 36430 is a hybrid sdBV(rs) pulsator exhibiting several low-amplitude g-modes and a strong p-mode pulsation. The latter shows a clear, periodic variation in its pulse arrival times. Fits to this phase oscillation imply BPM 36430 orbits a barycenter approximately 10 light-seconds away once every 3.1 days. Using the CHIRON echelle spectrograph on the CTIO 1.5 m telescope, we confirm the reflex motion by detecting a radial-velocity variation with semiamplitude, period, and phase in agreement with the pulse timings. We conclude that a white dwarf companion with minimum mass of approximate to 0.42 M (circle dot) orbits BPM 36430. Our study represents only the second time a companion orbiting a pulsating hot subdwarf or white dwarf has been detected from pulse timings and confirmed with radial velocities.
Author details: | Bryce A. SmithORCiD, Brad N. BarlowORCiD, Benjamin RosenthalORCiD, J. J. HermesORCiD, Veronika SchaffenrothORCiDGND |
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DOI: | https://doi.org/10.3847/1538-4357/ac9384 |
ISSN: | 0004-637X |
ISSN: | 1538-4357 |
Title of parent work (English): | The astrophysical journal : an international review of spectroscopy and astronomical physics |
Publisher: | IOP Publ. Ltd. |
Place of publishing: | Bristol |
Publication type: | Article |
Language: | English |
Date of first publication: | 2022/11/02 |
Publication year: | 2022 |
Release date: | 2024/01/22 |
Volume: | 939 |
Issue: | 1 |
Article number: | 57 |
Number of pages: | 6 |
Funding institution: | NASA [80NSSC21K0364]; TESS Guest Investigator Programs [80NSSC20K0592,; 80NSSC22K0737]; Deutsche Forschungsgemeinschaft [GE2506/9-1]; NASA's; Science Mission directorate |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |