 Greetings and welcome to the Introduction to Astronomy! One of the things that I like to do in each of my introductory astronomy classes is to begin the class with the astronomy picture of the day. From the NASA website that is apod.nasa.gov slash apod. And today's picture for August 28th of 2023 is titled Star Formation in the Pac-Man Nebula. So what do we see here? This is often known as the Pac-Man Nebula because of its distinctive shape and also is called by its catalogue designation of NGC 281. Now this is an example of a star forming region. So we see a number of different things here including some dark dusty nebulae and in fact some very dense globules called bach globules that are seen against the brighter light of the nebula itself. So those are dark dense regions where stars are in the process of forming. So star formation is an ongoing process. It doesn't just happen all at once. Stars will form at different rates. A more massive star will form quickly and a low mass star will form more slowly. Even within a star forming region stars will start their formation at different times as the star formation progresses through the molecular cloud. So that's what we're just starting. We're seeing here is some of that and some of the stars have already formed at the center in that bluish region and others are still in the process of forming and in fact you can see tendrils of material pointing towards the star at the center. Those tendrils again are where stars are still just beginning to form and have not yet broken out of their cocoons. So they're hiding in there and will eventually emerge as they begin to produce their own energy by fusing hydrogen into helium. Now the colors we see here are looking at a very distinct emission of different elements. So to highlight the nebula we look at what we use, we call narrow band images. We're looking at just very specific wavelengths and that allows us to get more detail about the nebula than we would if we took a broadband image that was looking at all of the light. So sometimes by focusing just on the light that the gas is emitting we can see far more detail within that gas and not overly emphasize other portions of the nebula. So here we get to see that as a star forming region stars are still in the process of formation here and over the next few hundred thousand million years the more stars will be added to the star cluster forming at the center. Now if you notice that the center is starting to thin out a bit that is also what happens. The energy from those stars that form will then push out the gas and dust that were there and eventually expel them outwards. So in the long run we will have just a cluster of stars there and the nebula itself will be gone. Of course in a galaxy like our own star formation is in even earlier stages and more nebulae like this are currently forming. Just remember that the time scales are so long that we will never see these changes. So we will never see the Pac-Man nebula change into something else. However if we could watch it over tens of thousands of years we would see it slowly getting eaten away by the stars that have formed from it. So that was our picture of the day for August 28th of 2023. It was titled Star Formation in the Pac-Man Nebula. We'll be back again tomorrow for the next picture previewed to be Spiral Web so we'll see what that is about tomorrow and until then have a great day everyone and I will see you in class.