1 00:00:06,715 --> 00:00:07,924 This is the Cat's Eye nebula. 2 00:00:07,924 --> 00:00:11,302 It's in the constellation Draco, about 3,100 3 00:00:11,302 --> 00:00:13,138 light years from us. 4 00:00:14,472 --> 00:00:16,016 It's called the Cat’s Eye nebula 5 00:00:16,016 --> 00:00:19,561 because of the resemblance, the appearance of cat's eyes. 6 00:00:22,605 --> 00:00:25,191 We have at the very center of it a bright star. 7 00:00:25,775 --> 00:00:29,279 The star has been in the process of dying for many thousands of years. 8 00:00:29,738 --> 00:00:33,408 When the star gets near the end of its life, it expands inside 9 00:00:33,491 --> 00:00:37,203 as it runs out of hydrogen at the center and has to turn to fusing helium 10 00:00:37,203 --> 00:00:38,246 instead of hydrogen. 11 00:00:38,246 --> 00:00:39,539 The star expands, 12 00:00:39,539 --> 00:00:43,168 and it can get very unstable as you get near the end of its lifetime, 13 00:00:43,168 --> 00:00:46,546 which is when it starts throwing off these pulses of material. 14 00:00:48,131 --> 00:00:51,092 You see rings here, a whole set of 11 different rings 15 00:00:51,092 --> 00:00:52,302 that go all the way around 16 00:00:52,302 --> 00:00:55,638 the star, that almost look like tree rings. 17 00:00:56,389 --> 00:01:01,102 In addition to these rings of light that you see, you see these pointed 18 00:01:01,102 --> 00:01:04,647 nebula, which are jets of material coming out along the north 19 00:01:04,647 --> 00:01:06,357 and south magnetic poles. 20 00:01:07,484 --> 00:01:07,776 I love to 21 00:01:07,776 --> 00:01:11,780 think of this as providing us a fossil record in the same way 22 00:01:11,780 --> 00:01:14,783 that if you look through your layers of stone 23 00:01:14,908 --> 00:01:18,369 or you look through a slice of a tree or you see the tree rings, 24 00:01:18,536 --> 00:01:22,957 it allows you to see what was happening at different periods of time 25 00:01:22,957 --> 00:01:24,375 in the history of the star. 26 00:01:24,375 --> 00:01:30,423 So, somewhere like 15,000 years ago is when the instability stage of the star 27 00:01:30,632 --> 00:01:35,261 occurred and started throwing off material to form the rings of dust. 28 00:01:35,553 --> 00:01:40,934 And then more recently, a thousand years ago, it started throwing off the hot gases, 29 00:01:40,934 --> 00:01:44,521 which are glowing at the center and give you the very intricate patterns 30 00:01:44,521 --> 00:01:46,147 and structures that you see now. 31 00:01:50,151 --> 00:01:53,029 So you've got jets coming out of the magnetic poles. 32 00:01:53,279 --> 00:01:58,451 You have ellipsoids and circles of hot gas, and you've got 33 00:01:58,451 --> 00:02:02,747 spherically symmetric rings of dust, all wrapped up in one little package. 34 00:02:06,417 --> 00:02:09,462 It's the foundations for the next generation of stars. 35 00:02:09,546 --> 00:02:13,174 So this material gets thrown out into what we call the interstellar medium, 36 00:02:13,174 --> 00:02:18,012 the space between the stars and the material in that space between the stars. 37 00:02:18,012 --> 00:02:21,933 And that will later on collect together gravitationally, 38 00:02:21,933 --> 00:02:25,145 will pull together and form new stars and new solar systems.