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Type I Supernovae. Eric LeJeune. Supernova. High-mass star’s final brilliance Star explodes A turning off or sudden turn on of nuclear fusion. Classifying. Type I & Type II Type I doesn’t have hydrogen Type Ia, Ib, Ic Type Ia Exploded white dwarf Type Ib & Ic
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Type I Supernovae Eric LeJeune
Supernova • High-mass star’s final brilliance • Star explodes • A turning off or sudden turn on of nuclear fusion
Classifying • Type I & Type II • Type I doesn’t have hydrogen • Type Ia, Ib, Ic • Type Ia • Exploded white dwarf • Type Ib & Ic • Massive stars that have blown away outer layers • Doesn’t have a silicon line like type Ia
Single Degenerate Model Double Degenerate Model What leads to a Ia supernova?
Single Degenerate Model • Two sun-like stars in binary system • One goes to red giant, to white dwarf • The other star eventually goes red giant • White dwarf accretes • Chandrasekhar limit and nuclear fusion
Deflagration and detonation Brighter than entire galaxies The Explosion
Supernova 2005ke Visible UV X-Ray
The Aftermath • No leftovers, no neutron star or black hole • The white dwarf is completely obliterated
Implications • Similar compositions, same mass • Practically same brightness • Can measure distances • Observed Brightness = Luminosity 4π*Distance2 • Standard candle
The Universe’s Accelerating Expansion • Observe supernova • Determine distance • Results are farther away, and receding faster than expected in a universe expanding at a constant rate • Conclude accelerating expansion
Core Collapse • Super massive star at the end of its lifetime • Star has layers of fused chemical elements up to iron • Iron does not fuse so the core can’t generate heat. • Once the core reaches the Chandrasekhar mass, the core pressure drops and overlying material falls in.
More Core Collapse • The core collapses and material bounces off the core, resulting in a shock wave • Neutrino pulse propels shock wave • Shock wave blows star apart
Type Ib & Ic Supernovae • Type II supernovae • Type Ib supernovae • Blown off hydrogen shell • Type Ic supernovae • Blown off hydrogen and helium shells
Type Ib (SN 2005bf) Type Ic (SN 2006jc) Visualizing Type Ib & Ic Supernovae
Images • http://apod.nasa.gov/apod/image/0506/wd_cxc_full.jpg • http://chandra.harvard.edu/photo/2007/deml238/deml238_4panel.jpg • http://csp1.lco.cl/~cspuser1/PUB/PROJ/CI/c1/sn05bf.html • http://en.wikipedia.org/wiki/Image:Core_collapse_scenario.png • http://imagine.gsfc.nasa.gov/Images/news/SN2005ke_labels.jpg • http://ircamera.as.arizona.edu/NatSci102/images/lec22_07.gif • http://space.newscientist.com/data/images/ns/cms/dn8368/dn8368-1_579.jpg • http://upload.wikimedia.org/wikipedia/commons/2/27/Evolved_star_fusion_shells.png • http://www.eurekalert.org/multimedia/pub/web/3142_web.jpg • http://www.nso.lt/stories/img/starchild.jpg • http://www.supernovae.net/sn2006/u4904s5.jpg
Works Referenced • Bennett, Jeffrey, Megan Donahue, Nicholas Schneider, and Mark Voit. The Cosmic Perspective. 3rd ed. Boston: Addison Wesley, 2004. • "Dark Energy." ChemistryDaily.com. 01 Jan 2007. 27 Nov 2007 <http://www.chemistrydaily.com/chemistry/Accelerating_universe>. • Goldhaber, Gerson and Saul Perlmutter. "A study of 42 type Ia supernovae and a resulting measurement of ΩM and ΩΛ." Physics Reports 307.1-4. 01 Dec 1998 325-331. 27 Nov 2007 <http://www.sciencedirect.com>. • Hillebrandt, Wolfgang, Hans-Thomas Janka, and Ewald Müller. "How to Blow Up a Star." Scientific American Oct. 2006: 43-49. • Leibundgut, Bruno and JesperSollerman. "A cosmological surprise: the universe accelerates." Europhysics News 32.4. 2001 27 Nov 2007 <http://www.eso.org/~bleibund/papers/EPN/epn.html>. • "Supernova." wikipedia.org. 27 Nov 2007. Wikimedia Foundation, Inc.. 27 Nov 2007 <http://en.wikipedia.org/wiki/Supernova>. • "Type Ia Supernova." wikipedia.org. 25 Nov 2007. Wikimedia Foundation, Inc.. 27 Nov 2007 <http://en.wikipedia.org/wiki/Type_Ia_supernova>. • Van Dyk, Schuyler D.. "ASTRONOMY: Elusive Supernova Progenitors." Science 302.5648. 14 Nov 2003 1161-1162. 27 Nov 2007 <http://www.sciencemag.org/cgi/content/full/302/5648/1161>. • Wawrzyn, Alexander. "Modeling Supernovae with PHOENIX." www.hs.uni-hamburg.de. 05 Sep 2006. Universität Hamburg. 27 Nov 2007 <http://www.hs.uni-hamburg.de/EN/For/ThA/phoenix/supernova.html>.