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Abstract We report the discovery of SDSS J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive (>1M⊙at 2σconfidence) companion with a period of 36 hr. We use a combination of spectroscopy, including data from the ongoing fifth-generation Sloan Digital Sky Survey (SDSS-V), and photometry to measure the stellar parameters of the primary pre-ELM WD. The lightcurve of the primary WD exhibits ellipsoidal variation, which we combine with radial velocity data andPHOEBEbinary simulations to estimate the mass of the invisible companion. We find that the primary WD has massM1= M⊙and the unseen secondary has massM2= M⊙. The mass of the companion suggests that it is most likely a near-Chandrasekhar-mass WD or a neutron star. It is likely that the system recently went through a Roche lobe overflow from the visible primary onto the invisible secondary. The dynamical configuration of the binary is consistent with the theoretical evolutionary tracks for such objects, and the primary is currently in its contraction phase. The measured orbital period puts this system on a stable evolutionary path which, within a few gigayears, will lead to a contracted ELM WD orbiting a massive compact companion.
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Spectroscopic Characterization of WD J000801.25-350450 and Its Two Comoving Companions
Abstract We present new spectroscopic data for Gaia DR3 2309499817384726016 (WD 0008-350A) and its two wide, comoving, low-mass companions. We confirm the white dwarf is a hydrogen rich DA, withTeff= 6200 ± 90 K and a mass of 0.63 ± 0.03M⊙, close to that of the average white dwarf. Near-infrared spectra of the two stellar companions to WD 0008-350A reveal that the inner companion is an M dwarf, exhibiting a spectral type of M8. Furthermore, the outer companion is identified as a possible M6 + M9 binary. This paper examines the evidence which suggests the system may be quadruple.
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- Award ID(s):
- 2238468
- PAR ID:
- 10674131
- Publisher / Repository:
- The Astronomical Journal
- Date Published:
- Journal Name:
- The Astronomical Journal
- Volume:
- 171
- Issue:
- 3
- ISSN:
- 0004-6256
- Page Range / eLocation ID:
- 171
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.3847/1538-3881/ae38d3
