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
Type Ia Supernovae
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

Type Ia Remnants
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

Type Ib & Ic Supernovae
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
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http://apod.nasa.gov/apod/image/0506/wd_cxc_full.jpg
http://chandra.harvard.edu/photo/2007/deml238/deml238_4pa
nel.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/dn
8368-1_579.jpg
http://upload.wikimedia.org/wikipedia/commons/2/27/Evolve
d_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 Jesper Sollerman. "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>.
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"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.unihamburg.de/EN/For/ThA/phoenix/supernova.html>.
THE END