The remnant and origin of the historical supernova 1181AD

TL;DR

This paper identifies the supernova of 1181 AD with the nebula Pa 30 and Wolf Rayet star Parkers, supporting the double-degenerate merger origin of Type Iax supernovae and providing the first detailed study of such a remnant.

Contribution

The study presents the first identification of SN 1181 with Pa 30 and Parkers star, supporting the double-degenerate merger origin of Type Iax supernovae in our galaxy.

Findings

Pa 30's age matches the 1181 AD event

Spectroscopy shows a nebula with approx. 1,100 km/s shock velocities

Event likely a subluminous Type Iax supernova

Abstract

The guest star of AD 1181 is the only historical supernova of the last millennium that is without a definite counterpart. The previously proposed association with supernova remnant 3C58 is in strong doubt because of the inferred age of this remnant. Here we report a new identification of SN 1181 with our codiscovery of the hottest known Wolf Rayet star of the Oxygen sequence (dubbed Parkers star) and its surrounding nebula Pa 30. Our spectroscopy of the nebula shows a fast shock with extreme velocities of approx. 1,100kms. The derived expansion age of the nebula implies an explosive event approx 1,000 years ago which agrees with the 1181 AD event. The on sky location also fits the historical Chinese and Japanese reports of SN 1181 to 3.5degrees. Pa 30 and Parkers star have previously been proposed to be the result of a double-degenerate merger, leading to a rare Type Iax supernova. The likely historical magnitude and the distance suggest the event was subluminous for normal supernova. This agrees with the proposed Type Iax association which would also be the first of its kind in the Galaxy. Taken together, the age, location, event magnitude and duration elevate Pa 30 to prime position as the counterpart of SN 1181. This source is the only Type Iax supernova where detailed studies of the remnant star and nebula are possible. It provides strong observational support for the double degenerate merger scenario for Type Iax supernovae.