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SupernovaBy: Courtney Lee and Matt TanakaBy: Courtney Lee and Matt Tanaka

SupernovaAn explosion of a massive An explosion of a massive

supergiant star.supergiant star.

One of the most energetic One of the most energetic explosive events.explosive events.

Occurs at the end of a star’s Occurs at the end of a star’s lifetime, when its nuclear lifetime, when its nuclear fuel is exhausted and it is no fuel is exhausted and it is no longer supported by the longer supported by the release of nuclear energy.release of nuclear energy.

If the star is particularly If the star is particularly massive, then its core will massive, then its core will collapse and in so doing will collapse and in so doing will release a huge amount of release a huge amount of energy.energy. This will cause a This will cause a blast wave that ejects the blast wave that ejects the star's envelope into star's envelope into interstellar space.interstellar space.

In a single cataclysm, a In a single cataclysm, a massive star may blow itself massive star may blow itself to bits, releasing as much to bits, releasing as much energy, for a brief time, as energy, for a brief time, as an entire galaxy. an entire galaxy.

SupernovaIt may shine with the brightness of 10 It may shine with the brightness of 10

billion suns.billion suns.

The total energy output may be 10The total energy output may be 104444 joules. joules.

Only seen in galaxies other than the Milky Only seen in galaxies other than the Milky Way.Way.

Tycho Brahe and Johannes Kepler, Tycho Brahe and Johannes Kepler, discovered bright supernovae occurring in discovered bright supernovae occurring in the Milky Way in 1572 and 1604.the Milky Way in 1572 and 1604.

no supernova has been seen in our Galaxy no supernova has been seen in our Galaxy since Kepler's.since Kepler's.

Type I SupernovaThe explosion and complete destruction of a dead star The explosion and complete destruction of a dead star

called a white dwarf.called a white dwarf.

Type I supernova can occur if the white dwarf is made of Type I supernova can occur if the white dwarf is made of carbon and if it is a member of a binary system.carbon and if it is a member of a binary system.

A white dwarf cannot be more massive than about 1.4 A white dwarf cannot be more massive than about 1.4 solar masses and remain stable.solar masses and remain stable.

if the white dwarf's companion star expands to become a if the white dwarf's companion star expands to become a red giant, some of its matter may be drawn away and red giant, some of its matter may be drawn away and sucked onto the surface of the white dwarf. sucked onto the surface of the white dwarf.

Type II SupernovaA massive star runs out of A massive star runs out of

thermonuclear fuel and can no thermonuclear fuel and can no longer sustain itself against the longer sustain itself against the inward pull of its own gravity.inward pull of its own gravity.

The star collapses in a matter The star collapses in a matter of seconds.of seconds.

The core is crushed into a tiny The core is crushed into a tiny object called a neutron star, object called a neutron star, which may be no more than 6 which may be no more than 6 mi (10 km) across. mi (10 km) across.

The outer layers collapse as The outer layers collapse as well, but when they encounter well, but when they encounter the extremely hard, rigid, the extremely hard, rigid, collapsed core, they bounce off collapsed core, they bounce off it.it.

Identifying Each Type

Astronomers can tell the type of a Astronomers can tell the type of a supernova by observing its total brightness supernova by observing its total brightness as well as its spectrum.as well as its spectrum.

Type I supernova release more energy and Type I supernova release more energy and therefore have a lower absolute magnitude.therefore have a lower absolute magnitude.

Type II has prominent hydrogen lines in Type II has prominent hydrogen lines in their spectra because hydrogen is the their spectra because hydrogen is the primary element in the exploding star.primary element in the exploding star.

Astronomers and sdadlSupernova

Type I supernova are useful Type I supernova are useful to astronomers trying to to astronomers trying to determine the distances to determine the distances to other galaxies.other galaxies.

Since all Type I supernova Since all Type I supernova have about the same have about the same absolute brightness, absolute brightness, astronomers can calculate astronomers can calculate how far away a Type I how far away a Type I supernova is by measuring supernova is by measuring its apparent brightness and its apparent brightness and then calculating how far then calculating how far away it must be to appear away it must be to appear that bright.that bright.

Type I supernovae serves as Type I supernovae serves as one of several kinds of one of several kinds of distance indicators that distance indicators that help us determine the size help us determine the size of the Universe.of the Universe.

EffectsWhen a supernova explodes, When a supernova explodes,

they have profound effects on they have profound effects on their surroundings in galaxies.their surroundings in galaxies.

The tremendous energy that is The tremendous energy that is liberated affects the gas in its liberated affects the gas in its environment, pushing on it environment, pushing on it and compressing it. If the gas and compressing it. If the gas was originally fairly dense, was originally fairly dense, then the compressed denser then the compressed denser gas can actually go on to gas can actually go on to collapse and form new stars. collapse and form new stars.

Later generations of stars Later generations of stars formed after the supernova formed after the supernova contain more heavy elements contain more heavy elements than previous generations. than previous generations.

The enrichment of the gas in The enrichment of the gas in our region of the Milky Way our region of the Milky Way reached such a point that a reached such a point that a sufficient quantity of heavy sufficient quantity of heavy elements existed to give rise elements existed to give rise to life here on Earth.to life here on Earth.

SummaryA supernova is an explosion of a A supernova is an explosion of a

massive supergiant star.massive supergiant star.

Occurs at the end of a stars lifetime Occurs at the end of a stars lifetime when its nuclear fuel is exhausted and is when its nuclear fuel is exhausted and is no longer supported by the release of no longer supported by the release of nuclear energy.nuclear energy.

The enrichment of the gas in our region The enrichment of the gas in our region of the milky way reached such a point of the milky way reached such a point that a sufficient quantity of elements that a sufficient quantity of elements existed to give rise to life here on earth.existed to give rise to life here on earth.

Works Cited"Supernova." HEASARC: NASA's Archive of Data on "Supernova." HEASARC: NASA's Archive of Data on

Energetic Phenomena. Web. 08 Feb. 2011. Energetic Phenomena. Web. 08 Feb. 2011. <http://heasarc.nasa.gov/docs/snr.html>.<http://heasarc.nasa.gov/docs/snr.html>.

"Supernovae." Test Page for Apache Installation. "Supernovae." Test Page for Apache Installation. Web. 08 Feb. 2011. <http://hyperphysics.phy-Web. 08 Feb. 2011. <http://hyperphysics.phy-astr.gsu.edu/hbase/astro/snovcn.html>.astr.gsu.edu/hbase/astro/snovcn.html>.

"Curious About Astronomy? Supernovae." Curious "Curious About Astronomy? Supernovae." Curious About Astronomy? Ask an Astronomer. Web. 08 About Astronomy? Ask an Astronomer. Web. 08 Feb. 2011. Feb. 2011. <http://curious.astro.cornell.edu/supernovae.php>.<http://curious.astro.cornell.edu/supernovae.php>.

"What Are Supernovae?" Index of /. Web. 08 Feb. "What Are Supernovae?" Index of /. Web. 08 Feb. 2011. 2011. <http://spider.ipac.caltech.edu/staff/vandyk/supern<http://spider.ipac.caltech.edu/staff/vandyk/supernova.html>.ova.html>.