2026 April 01 - The Claw and Bubble Nebulae

0:00Greetings and welcome to the astronomy picture of the day podcast. Today's picture is titled the claw and bubble nebulae. So what do we see here? Well here we turn this to the side a little bit to let it fill our screen a little bit better and what we see are two nebulae here and that is the claw nebula kind of reaching off over toward the bubble nebula. Now these are part of a star forming region and while it may look like almost a painting here it is really a region of star formation where gases are ionized by hot stars. So essentially the very hot stars rip electrons off of the atoms. How do they do that? Well with ultraviolet light a very high energy light that then rips electrons off with their energy and when those recombine they give off various wavelengths of light some of which we are seeing here. Here we see the yellow and blue

1:02associated with hydrogen and oxygen two of the more common elements in the universe. So they get ionized as they recombine they will give off specific wavelengths of light which is what is detected here. Now as a region of star formation you form very large stars first those are the ones that emit a lot of that ultraviolet light and therefore cause everything to glow. As those stars slowly die eventually the nebula will die out. Those bright stars will also use their stellar winds and will start to clear out the material that has formed within. So eventually all will have left here is a star cluster as everything else gets removed from the central regions it begins to hollow out leaving behind just the cluster of stars. But in the meantime for the next million years or so we get to see the nebula here as it slowly changes. Nothing we will notice

2:05over our lifetime but the patterns will slowly change as more stars form and eat away at the gas and dust that is here. Now star forming regions are prominent in galaxies like our own. Our galaxy is a spiral galaxy which has a lot of gas and dust that can form new stars. Other types of galaxies known as ellipticals do not have that so you wouldn't find something like this in an elliptical galaxy. You would not have the dust the gas and the star formation going on that we see in the spiral galaxy. So different types of galaxies form stars in different ways and at different times. Elliptical galaxies formed all their stars all at once in a massive burst long ago, maybe billions of years ago. Whereas spiral galaxies may have formed a lot of stars early on but they still retain enough gas and dust to continue forming stars today. So that was our

3:07picture of the day titled The Claw and Bubble Nebula. We'll be back again tomorrow for the next picture. Previewed to be Warping Space Time. So we'll see what that is about tomorrow. And until then have a great day everyone and I will see you in class.