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Quick introduction: Supernova ! Visible supernovae are uncommon and of great interest to astronomers. They occur when a massive star has burned up most.

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Presentation on theme: "Quick introduction: Supernova ! Visible supernovae are uncommon and of great interest to astronomers. They occur when a massive star has burned up most."— Presentation transcript:

1 Quick introduction: Supernova ! Visible supernovae are uncommon and of great interest to astronomers. They occur when a massive star has burned up most of its “fuel” and suddenly “collapses”. A shock wave is formed which blows off the outer layers of the star. Supernovae in our own galaxy had not been seen since the 1600’s until ………………………… 1987

2 One dramatic result of stellar evolution: a supernova remnant

3 Hydrostatic equilibrium maintains a star’s size during Stage 7

4 Stellar composition changes as the hydrogen is used up During stage 7 of stellar evolution, hydrogen burning causes a build-up of helium in the star’s core.

5 Hydrogen shell burning occurs around an “ash” core, which is mostly helium, and the temperature is T = 10 million K

6 Helium shell burning continues, and carbon burning commences

7 Heavy Element Fusion - shells like an onion

8 A Type II Supernova is a “core collapse” and occurs when the core is finally pure iron, which cannot be fused to other elements. The core collapses to a big ball of neutrons, which causes a shock wave to bounce back outward, which blows off the entire envelope of the red giant, to form a supernova remnant.

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11 1994

12 SN2005cs in M51(Whirlpool galaxy) discovered June 27, 2005

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14 Supernovae in our galaxy have been infrequent. Historical supernovae in the Milky Way (none observed by telescope !!!!): Recent supernovae by date: All supernovae since 1885: Links for supernovae on the web: Latest supernovae (by current brightness !): Supernova SN2005cs in M51 (Whirlpool galaxy): also see:

15 Supernova Remnants Vela supernova remnant Other examples: Cassiopeia A (link) (link)link N63A (link)link Crab nebula

16 M1 – the Crab Nebula is from a supernova seen in year A.D The remnant is 1800 pc away and the diameter is currently 2 pc.

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19 Astronomers have been waiting for hundreds of years for a bright, nearby supernova. Finally, one night in 1987… We learn the story of the observation in the movie “Death of a Star” (from the Nova series on PBS)

20 Supernova 1987A seen near nebula 30 Doradus

21 Supernova Light Curves fall into two types

22 Supernova 1987A was not typical

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26 Supernova 1987A linklink link link See mpeg animations of this.

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28 Eta Carinae will probably go supernova in the next 100,000 years or so. SEDS link SEDS link


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