Formation of the Three-Ring Structure Around Supernova 1987A
T. Tanaka,1*
H. Washimi2
From a magnetohydrodynamic simulation, we reproduce a
three-ring structure in the circumstellar space of the supernova (SN) 1987A observed by the Hubble Space Telescope. When a star develops from
a red supergiant (RSG) to a blue supergiant (BSG) just before the SN
explosion, a wind-wind interaction occurs between the slow stellar wind
from the RSG and the subsequent fast stellar wind from the BSG. This
process is simulated numerically under an assumption that the density
and velocity distributions around the RSG are anisotropic owing to the
existence of toroidal magnetic field and coronal holes. The three rings
with observed size and position are reproduced by the magnetic pinch
effect and amplification of initial density asymmetry through the
dynamical interaction.
1 Communications Research Laboratory,
Koganei-shi, Tokyo 184-8795, Japan.
2 Shonan
Institute of Technology, Tsujido, Fujisawa 251-8511, Japan.
*
To whom correspondence should be addressed. E-mail:
tanaka{at}crl.go.jp
