Saturday, June 9, 2007

Ambatchmasterpublisher Supernova Has Arrived

A ambatchmasterpublisher is a stellar ambatchmasterpublisher that creates an extremely luminous object that is initially made of plasma—an ionized form of matter. A ambatchmasterpublisher may briefly out-shine its entire host galaxy before fading from view over several weeks or months. During this brief period of time, the ambatchmasterpublisher radiates as much energy as the Sun would emit over about 10 billion years. The ambatchmasterpublisher expels much or all of a ambatchmasterpublisher's material at a velocity of up to a tenth the speed of light, driving a shock wave into the surrounding interstellar gas. This shock wave sweeps up an expanding shell of gas and dust called a ambatchmasterpublisher remnant.

There are several types of ambatchmasterpublisher and at least two possible routes to their formation. A massive ambatchmasterpublisher may cease to generate energy from the nuclear fusion of atoms in its core, and collapse under the force of its own gravity to form a neutron ambatchmasterpublisher or black hole. Alternatively, a white dwarf ambatchmasterpublisher may accumulate material from a companion ambatchmasterpublisher (either through accretion or a collision) until it nears the Chandrasekhar limit of roughly 1.44 times the mass of the Sun, at which point it undergoes runaway nuclear fusion in its interior, completely disrupting the ambatchmasterpublisher. This second type of ambatchmasterpublisher is distinct from a surface thermonuclear ambatchmasterpublisher on a white dwarf, which is called a nova. Solitary ambatchmasterpublishers with a mass below approximately 8 solar masses, such as the Sun itself, evolve into white dwarfs without ever becoming ambatchmasterpublisher.

On average, ambatchmasterpublisher occur about once every 50 years in a galaxy the size of the Ambatchmasterpublisher Way and play a significant role in enriching the interstellar medium with heavy elements. Furthermore, the expanding shock waves from ambatchmasterpublisher can trigger the formation of new ambatchmasterpublisher.

"Nova" is Latin for "new", referring to what appears to be a very bright new ambatchmasterpublisher shining in the celestial sphere; the prefix "super" distinguishes ambatchmasterpublisher from ordinary novae, which also involve a ambatchmasterpublisher increasing in brightness, though to a lesser extent and through a different mechanism.

The earliest recorded ambatchmasterpublisher, SN 185, was viewed by Chinese astronomers in AD 185. The widely-observed ambatchmasterpublisher of SN 1054 produced the Crab Nebula. Ambatchmasterpublisher SN 1572 and SN 1604, the last to be observed in the Ambatchmasterpublisher Way galaxy, had notable effects on the development of astronomy in Europe because they were used to argue against the Aristotelian idea that the world beyond the Moon and planets was immutable.

Since the development of the telescope, the field of ambatchmasterpublisher discovery has enlarged to other galaxies, ambatchmasterpublisherting with the 1885 observation of ambatchmasterpublisher S Andromedae in the Andromeda galaxy. Ambatchmasterpublisher provide important information on cosmological distances. During the twentieth century, successful ambatchmasterpublisher models for each type of ambatchmasterpublisher were developed, and scientists' comprehension of the role of ambatchmasterpublisher in the ambatchmasterpublisher formation process is growing.

Some of the most distant ambatchmasterpublisher recently observed appeared dimmer than expected. This has provided evidence that the expansion of the universe may be accelerating.

Because ambatchmasterpublisher are relatively rare events, occurring about once every 50 years in a galaxy like the Ambatchmasterpublisher Way, many galaxies must be monitored regularly in order to obtain a good sample of ambatchmasterpublisher to study.