Accretion in the binary system GG Carinae and implications for B[e] supergiants

Research output: Contribution to journalArticlepeer-review

Abstract

We simulate the hydrodynamics of the wind flow in the B[e] supergiant binary system GG Carinae and obtain the mass accretion rate on to the secondary and the observed light curve. We find an inhomogeneous Bondi-Hoyle-Lyttleton accretion into a curved accretion tail, and confirm that the accretion rate is modulated along the orbit, with a maximum close to periastron. We show that the accretion itself cannot account for the periodical variation in brightness. Instead, we explain the observed variation in the light curve with absorption by the accretion tail. Our results are in general agreement with previously derived stellar masses, orbital parameters, and the system orientation, but imply that the B[e] supergiant is more luminous. We find an effect related to the orbital motion of the two stars, in which the accretion tail is cut by the primary, and we term it the Lizard Autotomy Effect. As part of the effect, the primary is self accreting wind that it ejected earlier. The Lizard Autotomy Effect creates an outwardly expanding spiral shell made up of broken segments. We suggest that such a tail exists in other B[e] supergiant systems and can be the source of the circumstellar material observed in such systems. The accretion also forms a disc around the secondary near periastron that later vanishes. We suggest that the formation of such a disc can launch jets that account for the bipolar structure observed around some B[e] supergiants.

Original languageEnglish
Pages (from-to)5876-5886
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume523
Issue number4
DOIs
StatePublished - 1 Aug 2023

Keywords

  • (stars:) binaries: general
  • accretion, accretion discs
  • stars: emission-line, Be
  • stars: mass-loss
  • stars: massive
  • stars: winds, outflows

Fingerprint

Dive into the research topics of 'Accretion in the binary system GG Carinae and implications for B[e] supergiants'. Together they form a unique fingerprint.

Cite this