supernova remnant

(redirected from Bubble nebula)

supernova remnant

(SNR) The expanding shell of gas from a supernova explosion, consisting of the supernova ejecta and ‘swept-up’ interstellar gas. Young (< 1000 year old) supernova remnants are generally optically faint but are fairly strong radio and X-ray sources; the Crab nebula is exceptionally bright because it is energized by a central pulsar. Older supernova remnants appear as rings of bright filaments, again with associated radio and X-ray emission. Supernova remnants that have been observed at sufficiently high resolution can be loosely classified into two types. In shell SNRs, which constitute about 90% of all SNRs (including Tycho and Kepler), most of the observed radiation comes from a filamentary, often spherical shell; they seem to have no central power source and their luminosity is exclusively derived from the interaction of the supernova shell with the external medium. Plerions (or filled or filled-center SNRs) are now widely thought to be powered by a central pulsar – the Crab nebula is the archetypal example – and the observed radiation originates from the whole of the remnant. Compression by an expanding supernova remnant can trigger star formation in interstellar clouds. See also emission nebula.

supernova remnant

[¦sü·pər′nō·və ′rem·nənt]
(astronomy)
A nebula consisting of an expanding shell of gas that has been ejected by a supernova. Abbreviated SNR.
References in periodicals archive ?
The Bubble Nebula is an example of a rounder star nursery.
Like the Bubble Nebula, it is located in Cassiopeia.
Caption: APPLYING DECONVOLUTION Compared to the "before" image of the Bubble Nebula, NGC 7835, at top left, the "after" image to its right shows increased detail, and faint stars are made more apparent.
Astronomers trained the iconic telescope on this colorful feature, called the Bubble Nebula, or NGC 7635.
The Bubble Nebula lies 7,100 light-years from Earth in the constellation Cassiopeia.
The Bubble Nebula, also known as NGC 7635, is located 7,100 light-years from Earth in the constellation Cassiopeia, and is seven light-years across.
The term Bubble Nebula is used to mean two different things: the emission nebula NGC 7635 and a small, slightly oblate spherical structure inside NGC 7635, which gives the Bubble its name.
While processing these images, Dave noticed a delicate, perfectly round, bubble-like object approximately 4 arcminutes in diameter that was even more symmetrical than the well-known Bubble Nebula (NGC 7635).
NGC 7635, the Bubble Nebula, is a nearly symmetrical 6-light-year-wide clearing in the large cloud of hydrogen gas Sh 2162 located near the northern border of Cassiopeia.
In the case of the Bubble Nebula (NGC 7635), a remarkably spherical balloon of such gas is giving astronomers yet another look at the physics of stardeath.