1. Stellar Explosion has Many Layers Department of Physics National Tsing Hua University G.T. Chen 2006/11/06 Oct. 26, 2006 http://www.universetoday.com

3. Cassiopeia A  R.A. :23h 23m 26.7s  Dec. :+58 º 49' 03.00"  Distance : ~11000 light years  It is known as a supernova remnant  SNR 111.7-2.1  SNR 111.7-2.1  Apparent Dimension : 5 arc min ~ 10 light years ~ 10 light years

4. Cassiopeia A  It is the youngest known supernova remnant in our Milky Way, and the strongest extrasolar radio source in the sky.  Calculating its expansion back, astronomers have found that the supernova must have blown up around 1667  The original star is about 15 to 20 times solar mass and was made up of concentric shells of elements

6. News  From Spitzer ’ s observations, They have found new bits of the ‘ onion ’ layers that had not been seen before  This tells us that the star ’ s explosion was not chaotic enough  It ’ s possible that the star exploded in a uniform fashion, blowing its layers out in successive order. Then those layers should be preserved in the expanding debris

7. News  Spitzer ’ s infrared detectors were able to observed gases and dusts consisting of the middle-layer elements neon, oxygen and aluminum  It seems that most of the star ’ s original layers flew outward in successive order, but at different average speeds depending on where they started

8. This artist's concept illustrates that massive star before and after it blew up

9. News  Cassiopeia A is the ideal target for studying the anatomy of a supernova explosion

10. References  http://www.universetoday.com http://www.universetoday.com Oct. 26, 2006 Oct. 26, 2006  http://www.spitzer.caltech.edu/spitzer http://www.spitzer.caltech.edu/spitzer  http://chandra.harvard.edu/photo/0237

11. >>Thank you >Thank you<<

12.  Infrared data from the Spitzer Space Telescope are colored red; optical data from the Hubble Space Telescope are yellow; and X-ray data from the Chandra X-ray Observatory are green and blue

13.  Spitzer reveals warm dust in the outer shell with temperatures of about 10 0 C, and Hubble sees the filamentary structures of warmer gases about 10,000 0 C. Chandra shows hot gases at about 10 million 0 C

14. radio X-ray

15. optical

16. Infrared Reference