Intermediate-Mass Mergers: A New Scenario for Several FS CMa Stars

Abstract

We summarise the properties and nature of a peculiar group of B-type stars called FS CMa stars. These stars show the B[e] phenomenon, i.e., their spectra exhibit both forbidden emission lines and infrared excess. Such properties point to an extended circumstellar gas and dust component. Although the phenomenon has been explained in most B[e] stars, the origin and nature of FS CMa stars is disputed. Here, we focus on the merger hypothesis, for which evidence has recently been discovered.

invited talk at the conference: "Hot Stars: Life with Circumstellar Matter", October 14-19, 2024, Almaty, Kazakhstan

References in corpus (31)

• A high-resolution spectropolarimetric survey of Herbig Ae/Be stars - I. Observations and measurements
• On the binarity of Herbig Ae/Be stars
• Long-term evolution of a magnetic massive merger product
• Stellar triples on the edge; Comprehensive overview of the evolution of destabilised triples leading to stellar and binary exotica
• A population of transition disks around evolved stars: Fingerprints of planets? Catalog of disks surrounding Galactic post-AGB binaries
• High-Dispersion Spectroscopy of the X-Ray Transient RXTE J0421+560 (= CI Cam) during Outburst
• Toward Understanding the B[e] Phenomenon. VII. AS 386, a single-lined binary with a candidate black hole component
• Spectroscopic observations of the candidate sgB[e]/X-ray binary CI Cam
• The B-type Binaries Characterisation Programme I. Orbital solutions for the 30 Doradus population
• Herbig Stars: A Quarter Century of Progress
• Towards Understanding The B[e] Phenomenon: IV. Modeling of IRAS 00470+6429
• Photometry and low resolution spectroscopy of hot post-AGB candidates
• New spectroscopic observations of the B[e]/K binary system MWC 623
• A disk asymmetry in motion around the B[e] star MWC158
• Toward Understanding The B[e] Phenomenon: V. Nature and Spectral Variations of the MWC 728 Binary System
• Imaging the asymmetric dust shell around CI Cam with long baseline optical interferometry
• First detections of FS Canis Majoris stars in clusters. Evolutionary state as constrained by coeval massive stars
• Properties of Galactic B[e] Supergiants: V. 3 Pup -- constraining the orbital parameters and modeling the circumstellar environments
• CI Camelopardalis: The first sgB[e]-High Mass X-ray Binary Twenty Years on, a Supernova Imposter in our own Galaxy?
• Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon III. HD 50138
• First detection of a magnetic field in low-luminosity B[e] stars: New scenarios for the nature and evolutionary stages of FS CMa stars
• Lithium in coalesced non-compact stars
• Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon; I. V2028 Cyg
• Investigation of the Nature of the B[e] Star CI Cam in the Optical Range
• Dust evolution in the circumstellar disc of the unclassified B[e] star HD 50138
• FS CMa type binaries
• The mass distribution of stellar mergers: A new scenario for several FS CMa stars
• 2.5-MHD models of circumstellar discs around FS~CMa post-mergers : I. Non-stationary accretion stage
• CRIRES-VLT high-resolution spectro-astrometry as a tool in the search of small structures at the cores of Planetary Nebulae
• 2.5-MHD models of circumstellar discs around FS~CMa post-mergers : II. Stationary accretion stage
• Evolution of intermediate mass and massive binary stars: physics, mass loss, and rotation