The Cassiopeia A Supernova was of Type IIB

Abstract

Cassiopeia A is one of the youngest supernova remnants known in the Milky Way and a unique laboratory for supernova physics. We present an optical spectrum of the Cassiopeia A supernova near maximum brightness, obtained from observations of a scattered light echo - more than three centuries after the direct light of the explosion swept past Earth. The spectrum shows that Cassiopeia A was a type IIb supernova and originated from the collapse of the helium core of a red supergiant that had lost most of its hydrogen envelope prior to exploding. Our finding concludes a longstanding debate on the Cassiopeia A progenitor and provides new insight into supernova physics by linking the properties of the explosion to the wealth of knowledge about its remnant.

17 pages, 4 figures, including online supporting material; to be published in Science on 30 May 2008

References in corpus (1)

• Infrared Echoes near the Supernova Remnant Cassiopeia A

Cited by in corpus (6)

• Tycho Brahe's 1572 supernova as a standard type Ia explosion revealed from its light echo spectrum
• The Stellar Ancestry of Supernovae in the Magellanic Clouds - I. the Most Recent Supernovae in the Large Magellanic Cloud
• Cassiopeia A: dust factory revealed via submillimetre polarimetry
• The Kinematics of Kepler's Supernova Remnant as revealed by Chandra
• Carbon Monoxide in the Cassiopeia A Supernova Remnant
• Magnetohydrodynamic turbulence in supernova remnants