(This press release from April
10, 1995, is reproduced courtesy of the Space Telescope Science Institute.)
This is a NASA Hubble Space Telescope image of the tattered debris of a
star that exploded 3,000 years ago as a supernova. This supernova
remnant, called N132D, lies 169,000 light-years away in the satellite
galaxy, the Large Magellanic Cloud.
A Hubble Wide Field Planetary Camera 2 image of the inner regions of
the supernova remnant shows the complex collisions that take place as
fast moving ejecta slam into cool, dense interstellar clouds. This
level of detail in the expanding filaments could only be seen
previously in much closer supernova remnants. Now, Hubbles
capabilities extend the detailed study of supernovae out to the
distance of a neighboring galaxy.
Material thrown out from the interior of the exploded star at
velocities of more than four million miles per hour (2,000 kilometers
per second) plows into neighboring clouds to create luminescent shock
fronts. The blue-green filaments in the image correspond to
oxygen-rich gas ejected from the core of the star. The oxygen-rich
filaments glow as they pass through a network of shock fronts reflected
off dense interstellar clouds that surrounded the exploded star.
These dense clouds, which appear as reddish filaments, also glow as the
shock wave from the supernova crushes and heats the clouds.
Supernova remnants provide a rare opportunity to observe directly the
interiors of stars far more massive than our Sun. The precursor star
to this remnant, which was located slightly below and left of center in
the image, is estimated to have been 25 times the mass of our Sun.
These stars cook heavier elements through nuclear fusion, including
oxygen, nitrogen, carbon, iron etc., and the titanic supernova
explosions scatter this material back into space where it is used to
create new generations of stars. This is the mechanism by which the
gas and dust that formed our solar system became enriched with the
elements that sustain life on this planet. Hubble spectroscopic
observations will be used to determine the exact chemical composition
of this nuclear- processed material, and thereby test theories of
stellar evolution.
The image shows a region of the remnant 50 light-years across. The
supernova explosion should have been visible from Earths southern
hemisphere around 1,000 B.C., but there are no known historical records
that chronicle what would have appeared as a new star in the
heavens.
This true color picture was made by superposing images taken on 9-10
August 1994 in three of the strongest optical emission lines: singly
ionized sulfur (red), doubly ionized oxygen (green), and singly ionized
oxygen (blue).
Photo credit: Jon A. Morse (STScI) and NASA