Direct detections of white dwarfs in four WD+dM post-common envelope binaries within 20 pc

Abstract

Characterising post-common envelope binaries (PCEBs) containing a white dwarf and a main-sequence companion is essential for improving theories of binary evolution. This paper presents the first direct spectroscopic confirmations of the white dwarf components in four PCEB systems within 20 pc of the Sun: G 203-47, GJ 207.1, LHS 1817, and Wolf 1130. To detect the white dwarfs we obtained near-UV spectroscopy from STIS on the Hubble Space Telescope, fitting with white dwarf models and M dwarf proxy spectra. We provide estimates of the white dwarf effective temperatures, which range from approximately 5300 K to 6300 K. We compare these parameters to those determined from modelling with photometry alone, and find a 5 - 8 per cent discrepancy, due to emission features. Notably, 27 years after its initial detection, we confirm the presence of a white dwarf in G 203-47, which is the ninth closest white dwarf to the Sun. Using Swift XRT data, we find that despite the 14.9-day orbital period of G 203-47, it is not tidally locked, possessing a rotation period likely exceeding 100 days, and making it a rare example of a long-period PCEB formed via a brief common envelope interaction. We update the local white dwarf space density to (5.2 $\pm$0.4) $\times$ 10${}^{-3}$ pc${}^{-3}$, and compare our results to models from the Binary Populations and Spectral Synthesis (BPASS) framework, finding a good agreement with the predicted and observed numbers of PCEBs within 20 pc.

arXiv comment11 pages, 7 figures, plus appendix. Published in MNRAS 2026-07-14

References in corpus (65)

• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The K2 Mission: Characterization and Early results
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• Common Envelope Evolution: Where we stand and how we can move forward
• Models of Stars, Brown Dwarfs and Exoplanets
• The stellar activity-rotation relationship and the evolution of stellar dynamos
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• Reevaluating Old Stellar Populations
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• A catalogue of white dwarfs in Gaia EDR3
• Post-common-envelope binaries from SDSS. IX: Constraining the common-envelope efficiency
• The stellar rotation--activity relationship in fully convective M dwarfs
• The rotation and Galactic kinematics of mid M dwarfs in the Solar Neighborhood
• The MUSCLES Treasury Survey III: X-ray to Infrared Spectra of 11 M and K Stars Hosting Planets
• Spectroscopic analysis of DA white dwarfs with 3D model atmospheres
• Gaia Data Release 3: Processing and validation of BP/RP low-resolution spectral data
• The age, life expectancy, and space density of Post Common Envelope Binaries
• The White Dwarf Luminosity Function from SDSS Imaging Data
• The binarity of the local white dwarf population
• On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era
• Post Common Envelope Binaries from SDSS. I: 101 white dwarf main sequence binaries with multiple SDSS spectroscopy
• The Gaia 20 pc white dwarf sample
• Post-common envelope binaries from SDSS - VII: A catalogue of white dwarf-main sequence binaries
• Post common envelope binaries from SDSS. XII: The orbital period distribution
• $Gaia$ white dwarfs within 40 pc II: the volume-limited northern hemisphere sample
• Post-common envelope binaries from SDSS - XIV. The DR7 white dwarf-main sequence binary catalogue
• The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)
• 3D Model Atmospheres for Extremely Low-Mass White Dwarfs
• The 40 pc sample of white dwarfs from Gaia
• KOI-3278: A Self-Lensing Binary Star System
• The Dependence of Theoretical Synthetic Spectra on $\alpha$-enhancement in Young, Binary Stellar Populations
• Barium & related stars and their white-dwarf companions II. Main-sequence and subgiant stars
• The Exemplar T8 Subdwarf Companion of Wolf 1130
• Eclipsing Post Common Envelope Binaries from the Catalina Surveys
• Triage of the Gaia DR3 astrometric orbits. I. A sample of binaries with probable compact companions
• The White Dwarf Binary Pathways Survey I: A sample of FGK stars with white dwarf companions
• The mass and radius of the M-dwarf in the short period eclipsing binary RR Caeli
• Post-common envelope binaries from SDSS - XVI. Long orbital period systems and the energy budget of CE evolution
• Hoki: Making BPASS accessible through Python
• The HADES RV Programme with HARPS-N@TNG II. Data treatment and simulations
• A Catalogue of Potential Post Common Envelope Binaries
• Discovery of three self-lensing binaries from Kepler
• The White Dwarf Binary Pathways Survey IV: Three close white dwarf binaries with G-type secondary stars
• A Deep Proper Motion Catalog Within the Sloan Digital Sky Survey Footprint. II. The White Dwarf Luminosity Function
• GALEX Absolute Calibration and Extinction Coefficients Based on White Dwarfs
• The White Dwarf Binary Pathways Survey -- VIII: a post common envelope binary with a massive white dwarf and an active G-type secondary star
• Wolf 1130: A Nearby Triple System Containing a Cool, Ultramassive White Dwarf
• Wide post-common envelope binaries from Gaia: orbit validation and formation models
• The White Dwarf Binary Pathways Survey VI: two close post common envelope binaries with TESS light curves
• Local stellar formation history from the 40 pc white dwarf sample
• Forever Young: High Chromospheric Activity in M subdwarfs
• Spectroscopic Orbits of Eleven Nearby, Mid-to-Late M Dwarf Binaries
• The CARMENES search for exoplanets around M dwarfs: Spectroscopic orbits of nine M-dwarf multiple systems, including two triples, two brown dwarf candidates, and one close M-dwarf-white dwarf binary
• The White Dwarf Binary Pathways Survey VII: Evidence for a bi-modal distribution of post mass transfer systems?
• Formation of long-period post-common-envelope binaries I. No extra energy is needed to explain oxygen-neon white dwarfs paired with AFGK-type main-sequence stars
• Active Stars in the Spectroscopic Survey of Mid-to-Late M Dwarfs Within 15pc
• HST Low Resolution Stellar Library
• No longer impossible: the self-lensing binary KIC 8145411 is a triple
• A spectroscopic search for White Dwarf companions to 101 nearby M dwarfs
• Radial velocity homogeneous analysis of M dwarfs observed with HARPS I. Exoplanet detection and candidates
• Identification of new nearby white dwarfs using Gaia DR3
• Analysis of Previously Classified White Dwarf-Main Sequence Binaries Using Data from the APOGEE Survey
• A modest change in magnetic braking at the fully convective boundary explains cataclysmic variable evolution