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"
The 220 Mirrors of CRTF
04/10/1999
ven the largest of modern optical telescopes are small when compared with the light gathering power of the Central Receiver Test Facility (CRTF) located in New Mexico, USA. CRTF has 220 mirrors each over 7-meters in diameter all focused on a single tower. CRTF's main use is to investigate methods of collecting and using solar power. CRTF does not create focussed sky images like a normal astronomical telescope, but collects light from a much larger area. Recently, astronomers with the STACEE project have begun using CRTF to collect secondary light emitted when high-energy gamma rays strike the Earth's atmosphere. Photons in this range might allow further exploration of enigmatic gamma ray burst explosions, and might be emitted when cosmic rays from supernovae impact gas clouds in the interstellar medium.