Yummm MODELING Hello again This is Professor Jim Capy based in Sprite from Missouri, along with my $2 Orion and Mishman you've met earlier. And today we are going to do out of the open stacks astronomy free textbook chapter 22, stars from adolescence to old age. This is called the Ant Negra. It is a remnant of a star that I've exploded. Very beautiful. We're getting into deep with how stars work and the physics behind it. Here we have layers inside of star before and after it leaves main sequence. And what does it do? Here are some relative sizes of stars. You can see the sun over here to the left and that's the disease and the light is signaling up here. Very big stars. Beta juice is a red supergiant. You can see it outside in the wind time, late fall, winter, early spring. The right is in the top left hand corner of the shoulder and a very cool but big star low end temperature. We talked a little bit in chapter 21 about stars leaving the main sequence. How light you've all. So depending on how many solar masses, how many times the sun and mass it does, it would determine when and how it turns off the zero age main sequence and evolves into an older star that's not during fusion like the sun. This is Omega Centauri and you might see this in Arizona. I cannot see it in Missouri. But when I was in Tucson 20 years ago, I was able to stand at Helper Lamelon and see this huge globular star cluster, Waylow and the distance on the horizon. So if you go outside, you may see this. It is a Southern Hemisphere object. 16,000 light years away. Here is the jewel box and we gave some of these as you go at the items names called NGC. New guide to catalog and a number. Astronomers love catalogs. We have dozens of catalogs with weird names. So we can also look at clusters of stars. We can determine as soon that all the stars in a star cluster are going to be about the same age. So that whole cluster should turn off at the same time and we can determine the age of that cluster based on how and when it does get off the main sequence and that's really neat. Another Yang cluster NGC 2264, 2600 light years away. This is called the Christmas tree cluster. Very pretty. Here is another cluster on HR diagram. We can theoretically determine what this graph will look like. But we have to get to a telescope and we have to look at the stars and determine all the properties of them with a telescope. Another maybe one. Star cluster. We can see the light in the cluster being red lit up by these hot blue stars. Older clusters are going to turn off higher or up so they will follow the main sequence of line and then turn off and go up. This is a really famous cluster 472 county and you can see here how it lines up. A very good pattern. More clusters of different ages. A new cluster is a zero age main sequence. We can turn it off early at 100 million years. We can turn it off late in 10 billion years like the sun. Here is the evolution of a star like the sun on an HR diagram. We go on a main sequence to start. Once a star like the sun begins to die, it will leave the main sequence and it will make a track up here to a helium flash. All the hydrogen is going to run out and they're going to take the helium that's in the core and start burning it like burning ash. It's a very quick hot process. It comes back towards the main sequence but it doesn't all the way get there. Then we go into more helium flashes now in the shell out of the star. A low mass star, we can think of that as the sun, has these shells in it. A hydrogen envelope, hydrogen shell fusion, helium core, helium fusion and even beyond that a carbon oxygen core. More beautiful planetary nebula. Why are they called planetary nebula? They have nothing to do with planets. In a telescope, they look a little three dimensional. They do look three dimensional and that's how planets look too. These are the remnants of stars that have died and we see such beautiful art and space in the universe. Here is the most famous one. This is Ada Karini. This is a solid hemisphere. We cannot see this from the United States. It is way for ourselves by the pole. We have a very massive star working on exploding and dying. We are seeing this in a very rare case that we don't usually see. We need to see it before or after it has evolved. This one is doing it now. This is the shells for a massive star. We have the same shells where we get more shells going in this magnesium, oxygen fusion, silicon and sulfur fusion. You can imagine. Then in the bottom is iron ash. We cannot fuse iron in a star. That is the point when it explodes into a supernova. Thank you again for joining us and the dogs for chapter 22. Whether you enjoyed that episode of 10 Minute Astronomy, if so, check out all the other videos that not play this for 10 Minute Astronomy and other videos on my channel. Then hit the subscribe button right there. Thanks!