TY - JOUR
T1 - Discovery of a Proto-White Dwarf with a Massive Unseen Companion
AU - Adamane Pallathadka, Gautham
AU - Chandra, Vedant
AU - Zakamska, Nadia L.
AU - Hwang, Hsiang Chih
AU - Zenati, Yossef
AU - Hermes, J. J.
AU - El-Badry, Kareem
AU - Gänsicke, Boris T.
AU - Morrison, Sean
AU - Crumpler, Nicole R.
AU - Arseneau, Stefan
N1 - Publisher Copyright:
© 2024. The Author(s). Published by the American Astronomical Society.
PY - 2024/6/1
Y1 - 2024/6/1
N2 - We report the discovery of SDSS J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive (>1 M ⊙ at 2σ confidence) 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 and PHOEBE binary simulations to estimate the mass of the invisible companion. We find that the primary WD has mass M 1 = 0.18 − 0.02 + 0.02 M ⊙ and the unseen secondary has mass M 2 = 1.19 − 0.14 + 0.21 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.
AB - We report the discovery of SDSS J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive (>1 M ⊙ at 2σ confidence) 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 and PHOEBE binary simulations to estimate the mass of the invisible companion. We find that the primary WD has mass M 1 = 0.18 − 0.02 + 0.02 M ⊙ and the unseen secondary has mass M 2 = 1.19 − 0.14 + 0.21 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.
UR - https://www.scopus.com/pages/publications/85195589579
U2 - 10.3847/1538-4357/ad3e86
DO - 10.3847/1538-4357/ad3e86
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AN - SCOPUS:85195589579
SN - 0004-637X
VL - 968
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 42
ER -