Pre-explosion Spiral Mass Loss of a Binary Star Merger

Ondrej Pejcha, Brian D. Metzger, Jacob G. Tyles, Kengo Tomida

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

Binary stars commonly pass through phases of direct interaction, which result in the rapid loss of mass, energy, and angular momentum. Though crucial to understanding the fates of these systems, including their potential as gravitational wave sources, this short-lived phase is poorly understood and has thus far been unambiguously observed in only a single event, V1309 Sco. Here we show that the complex and previously unexplained photometric behavior of V1309 Sco prior to its main outburst results naturally from the runaway loss of mass and angular momentum from the outer Lagrange point, which lasts for thousands of orbits prior to the final dynamical coalescence, much longer than predicted by contemporary models. This process enshrouds the binary in a "death spiral" outflow, which affects the amplitude and phase modulation of its light curve, and contributes to driving the system together. The total amount of mass lost during this gradual phase (∼0.05 M⊙) rivals the mass lost during the subsequent dynamical interaction phase, which has been the main focus of "common envelope" modeling so far. Analogous features in related transients suggest that this behavior is ubiquitous.

Original languageEnglish
Article number59
JournalAstrophysical Journal
Volume850
Issue number1
DOIs
Publication statusPublished - 2017 Nov 20
Externally publishedYes

Keywords

  • binaries: close
  • binaries: eclipsing
  • stars: evolution
  • stars: individual (V1309 Sco)

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Pre-explosion Spiral Mass Loss of a Binary Star Merger'. Together they form a unique fingerprint.

Cite this