New clues to the Cassiopeia A supernova progenitor

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/169926· OSTI ID:5541146

Fesen, R A; Becker, R H ^[1]

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1. Dartmouth College, Hanover, NH (USA) Colorado, University, Boulder (USA) California, University, Davis (USA) Lawrence Livermore National Laboratory, Livermore (USA)

Optical spectra of filaments in Cas A's northeastern ejecta jet reveal one knot which exhibits the H-alpha and forbidden N II emissions like those seen in the remnant's quasi-stationary flocculi plus forbidden O I, forbidden O III, and forbidden S II emissions like those of the remnant's fast-moving knots. Discovery of this chemically peculiar knot suggests that some turbulent mixing may have occurred in the remnant's jet between underlying O and S-rich gas and surface layer material. The mixed ejecta knot's composition further suggests that at the time of its supernova outburst the Cas A progenitor possessed a thin outer layer of hydrogen. The presence of photospheric hydrogen sets an important constraint on the evolutionary phase of this remnant's probable Wolf-Rayet progenitor and means that the Cas A supernova could have briefly displayed H-alpha emission at early phases like that seen for SN 1987 K. 33 refs.

• OSTI ID: 5541146
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 371; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
ELEMENTS
ERUPTIVE VARIABLE STARS
FILAMENTS
HYDROGEN
MAIN SEQUENCE STARS
MIXING
MORPHOLOGY
NEBULAE
NONMETALS
SPECTRA
STAR EVOLUTION
STARS
SUPERNOVA REMNANTS
SUPERNOVAE
VARIABLE STARS
VISIBLE SPECTRA
WOLF-RAYET STARS