Supernova
A supernova is the explosive death of a star, during which it rapidly ejects most of its mass in a brilliant burst of light. In core‑collapse supernovae (Types Ib, Ic, II), massive stars (≥ 8 solar masses) exhaust their nuclear fuel, collapse under gravity, and explode. In Type Ia supernovae, a white dwarf in a binary system undergoes runaway fusion after accreting mass. These events deliver heavy elements into space, leave behind neutron stars or black holes, and power typical shock‑front supernova remnants.
Source: heasarc.gsfc.nasa.gov
APODs including "Supernova"
SGR 1900+14: Magnetar
03/09/1998
On August 27th an intense flash of X-rays and gamma-rays swept through our Solar System. Five spacecraft of the Third InterPlanetary gamma-ray burst Network, Ulysses, WIND, RXTE, NEAR, and BeppoSAX, recorded the high energy signal -- a signal so strong that it saturated detectors on WIND and RXTE and triggered the safety mode automatic shut-off of the NEAR gamma-ray instrument! As plotted here, the count rate for the Ulysses detector abruptly spiked to a high level and then slowly tailed off showing smaller peaks roughly every 5 seconds. The signal and location provided by these spacecraft observations leads researchers to identify the source as a dramatic flare-up from one of only four previously known "Soft Gamma Repeaters" . These exotic sources of gamma-rays are believed to be highly magnetized spinning neutron stars called Magnetars. Imaginatively cataloged as SGR 1900+14, this magnetar is estimated to have been born in a supernova explosion about 1,500 years ago and to have a magnetic field 500,000,000,000,000 times stronger than Earth's.