... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2015 August 28 . Puppis A Supernova Remnant . Image Credit Copyright : Don Goldman . Explanation: Driven by the explosion of a massive star, supernova remnant Puppis A is blasting into the surrounding interstellar medium about 7,000 light-years away. ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2000 January 3 . Cas A Supernova Remnant in X-Rays . ... Explanation: The complex shell of a star seen to explode 300 years ago is helping astronomers to understand how that star exploded. The above recently released image of supernova remnant Cassiopeia A (Cas A) shows unprecedented detail in three X-ray colors. ... About APOD > . ...

Supernova 1987A in LMC . One day in 1987, an astronomer by the name of Ian Shelton was making observations of the Tarantula Nebula in Large Magellanic cloud at Las Campanas Observatory, and he noticed something strange on his image. ... SN 1987A got as bright as 2.7, the only other recent SN even to come close was 1885A in M31 which got up to mag 6. ... Mag 4.5 . ... IAUC 4318 2/25/87 Type II? ... IAUC 7354 2/1/00 New structure in the inner ring . ... IAUC 7360 2/7/00 HST observation of new spot . ...

... We have compiled the Catalogue of extragalactic supernovae using the GCVS card catalogue. ... Doubtful (?), or rejected (-) SN 8 A1 --- RemFlag [*] The '*' indicates a remark in sn_rem.dat 10- 19 A10 --- Gal Parent galaxy designation 21- 22 I2 h RAh Right Ascension 1950 of Parent galaxy 23- 24 I2 min RAm Right Ascension 1950 (minutes) 25- 28 F4.1 s RAs Right Ascension 1950 (seconds) 29 A1 --- DE- Declination 1950 (sign) 30- 31 I2 deg DEd Declination 1950 of Parent ...

... Here is a brief outline of the current theory of the events in the early history of the solar system: . A cloud of interstellar gas and/or dust (the "solar nebula") is disturbed and collapses under its own gravity. ... The gas cools off enough for the metal, rock and (far enough from the forming star) ice to condense out into tiny particles. (i.e. some of the gas turns back into dust). ... Once the larger of these particles get big enough to have a nontrivial gravity, their growth accelerates. ...