Features of the Evolution of Remnants of Supernova SN 1987A Based on Published Studies Obtained with the Hubble and James Webb Space Telescopes

The Supernova SN 1987A in the Large Magellanic Cloud can be considered a natural testbed for testing hypotheses about the evolution of massive stars and the formation of compact remnants around them. Photometric, spectral, and polarimetric observations of this Supernova, conducted by us in February-December 1987 at the Tarija Astronomical Observatory in the Republic of Bolivia, showed that in May 1987 its brightness reached a maximum with an apparent magnitude of +3.5m. The spectra obtained by us in March 1987 showed emission features in the range of 397…589 nm, the wavelength shift of which corresponded to the values of the expansion velocity of the Supernova envelope of 5500…8900 km/s. Images obtained with the help of the Hubble Space Telescope (HST) revealed a system of three ionized gas rings surrounding the explosion site. The central ring, about one light-year in diameter, lies in the plane of the equator of the star of the Supernova’s progenitor, and two large outer rings are located in parallel planes in front and behind it. The outer rings could have been formed not by a direct mass ejection, but by a high-energy plasma jet that precesses around its axis. The source of such a jet could be such a compact object as a neutron star or a black hole that is part of a binary system. Analysis of the spots on these rings showed that the thickenings located on the opposite rings are symmetrical about some point that does not coincide with the geometric center of the explosion. It is believed that the precursor of Supernova SN 1987A, the star Sanduleak –69°202, with a mass of up to 20 solar masses, could have been the product of the merger of two stars in a close binary system about 20 000 years ago. The search for a neutron star at the center of the supernova SN 1987A received a new impetus with the start of operations of the James Webb Space Telescope (JWST) in 2022. Since argon and sulfur are synthesized in the deep layers of a massive star immediately before the explosion, their presence in a highly ionized state in the center of the Supernova remnant became a strong argument for the presence of a young neutron star there. Experience in studying SN 1987A may be important for interpreting the structures of other planetary nebulae, such as the “Hourglass” Nebula MyCn 18, DM Taurus, etc.