A Spectroscopic and Interferometric Study of W Serpentis Stars. I. Circumbinary Outflow in the Interacting Binary W Serpentis

Bibliographic Details
Title: A Spectroscopic and Interferometric Study of W Serpentis Stars. I. Circumbinary Outflow in the Interacting Binary W Serpentis
Authors: Katherine Shepard, Douglas R. Gies, Gail H. Schaefer, Narsireddy Anugu, Fabien R. Baron, Cyprien Lanthermann, John D. Monnier, Stefan Kraus, Theo ten Brummelaar
Source: The Astrophysical Journal, Vol 977, Iss 2, p 236 (2024)
Publisher Information: IOP Publishing, 2024.
Publication Year: 2024
Collection: LCC:Astrophysics
Subject Terms: Interacting binary stars, Stellar mass loss, Long baseline interferometry, High resolution spectroscopy, Astrophysics, QB460-466
More Details: W Serpentis is an eclipsing binary system and the prototype of the Serpentid class of variable stars. These are interacting binaries experiencing intense mass transfer and mass loss. However, the identities and properties of both stars in W Ser remain a mystery. Here, we present an observational analysis of high-quality, visible-band spectroscopy made with the Apache Point Observatory 3.5 m telescope and Astrophysical Research Consortium Echelle Spectrograph spectrograph plus the first near-IR, long-baseline interferometric observations obtained with the Center for High Angular Resolution Astronomy Array. We present examples of the appearance and radial velocities of the main spectral components: prominent emission lines, strong shell absorption lines, and weak absorption lines. We show that some of the weak absorption features are associated with the cool mass donor, and we present the first radial velocity curve for the donor star. The donor’s absorption lines are rotationally broadened, and we derive a ratio of donor to gainer mass of 0.36 ± 0.09 based on the assumptions that the donor fills its Roche lobe and that it rotates synchronously with the orbit. We use a fit of the All-Sky Automated Survey light curve to determine the orbital inclination and mass estimates of 2.0 M _⊙ and 5.7 M _⊙ for the donor and gainer, respectively. The partially resolved interferometric measurements of orbital motion are consistent with our derived orbital properties and the distance from Gaia EDR3. Spectroscopic evidence indicates that the gainer is enshrouded in an opaque disk that channels the mass transfer stream into an outflow through the L3 region and into a circumbinary disk.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1538-4357
Relation: https://doaj.org/toc/1538-4357
DOI: 10.3847/1538-4357/ad82e7
Access URL: https://doaj.org/article/3beb98d6023b4f49bc5e8473337f7b3c
Accession Number: edsdoj.3beb98d6023b4f49bc5e8473337f7b3c
Database: Directory of Open Access Journals
More Details
ISSN:15384357
DOI:10.3847/1538-4357/ad82e7
Published in:The Astrophysical Journal
Language:English