The Supernovae
Over the past 1,000 years, there have been six known supernovas in the Milky Way, the most recent of which discovered in 1604 by German Astronomer, Johannes Kepler, four years before the telescope was invented. In the sky, to the naked eye, it appears to be a new star. Modern technology, however, has pieced together a clearer image, “a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 6 million kilometers per hour (4 million mph)” (Hill). But what, exactly, makes a supernova? What is a supernova? The word itself is easy enough to understand with a basic knowledge of the words that make it up, a combination of understood “super”, (very large or powerful), and “nova”, (a star that suddenly increases its light output tremendously and then fades away to its former obscurity in a few months or years ) (Dict). A supernova, to put it simply, is the explosive death of a single or multiple stars, brought about by pressure one way or another. When a star supernovas, either it 's nuclear fuel supply has run out and it collapses under its own weight due to the lack of pressure, or a star that has already died collects matter to such a density that it triggers a thermonuclear explosion (Hubb). These deaths are classified into two main types, Type I and Type II, each with their own sub-classifications, and differentiated from each other by their mass and the appearance of hydrogen in their spectra, (or, the light it gives off). The Type I supernova occurs in binary pairs, lacks the hydrogen in its spectra, and originates from a white dwarf, (stars that are already dead), occurring when the gas of a nearby star accumulates, compressing the star until the reaction is triggered (Thomp). While a star may die without becoming a supernova, it is the explosive properties of the death that make it so. (A supernova 's explosion creates a light that can be observed from up to 10 billion light years away)
Citations: Anderson, Janet, and Megan Watzke. "NASA - Supernova Explosions Stay in Shape." NASA - Home. NASA, 17 Dec. 2009. Web. 13 Sept. 2011. . Dictionary and Thesaurus - Merriam-Webster Online. Web. 13 Sept. 2011. . Fullerton, Stephen. "Galactic Explosions – Novae, Supernovae, Hypernovae, and Gamma Ray Bursts." Organizations - Missouri State University. 01 May 2004. Web. 13 Sept. 2011. . Hill, Gay Yee, Donald Savage, Megan Watzke, and Donna Weaver. "NASA - Great Observatories May Unravel 400-Year-Old Supernova Mystery." NASA - Home. NASA, 10 June 2004. Web. 13 Sept. 2011. . "HubbleSite - Reference Desk - FAQs." HubbleSite - Out of the Ordinary...out of This World. Web. 13 Sept. 2011. . Thompson, Andrea. "What Is A Supernova? | Space.com." Space, NASA Information & News | Outer Space Flight Videos & Pictures | Astronomy, Solar System Images | Space.com. Space.com, 04 May 2009. Web. 13 Sept. 2011. . "Type Ia Supernova." Cosmos. Swinburne University of Technology. Web. 13 Sept. 2011. . "Type Ib Supernova." Cosmos. Swinburne University of Technology. Web. 13 Sept. 2011. . "Type Ic Supernova." Http://astronomy.swin.edu.au/cosmos/T/Type+Ic+Supernova. Swinburne University of Technology. Web. 13 Sept. 2011. .