Lois & Clark Forums Forums General Discussion Off Topic Cat's Eye in space, or what the Sun will once look like

Okay, because of all the talk about the environment and the Sun, I can't resist posting a link to this page , which shows what the Sun will look like when it has run thorugh not only the main sequence but also the red giant phase. After that, stars like the Sun will start expelling their outer layers. Briefly, those outer layers will shine and flouresce, lit by the now naked, hot, but cooling stellar core. These luminous surrounding clouds, the remnants of the star's red giant phase, are called a planetary nebula.

Take a look at the image! Beautiful, ain't it? Look at the shape of the outermost shells of gas, which appear to have been expelled rather violently. Further in, there is an almost perfectly circular brightness, but still closer in you can see an elongated, twisted shape. At the very center of the nebula, you can see the exposed core of the star that was once much like the Sun. The temperature of that core is about 80,000 degrees Kelvin. That's a lot, certainly compared with the temperature of the Sun's outermost luminous shell, its so called photosphere, whose temperature is about 6,000 degrees Kelvin. However, astronomers estimate that the temperature of the Sun's core is about 15 million degrees Kelvin. The exposed stellar core of the planetary nebula in the picture above was once about that hot, too. You can imagine how much heat it has lost since then. But it is that lost heat that makes the clouds of the nebula flouresce.

You can see a galaxy to the left of the planetary nebula. The distance to the galaxy is approximately 350 million lightyears, and the distance to the nebula is about 3000-3500 lightyears. That means that the galaxy is about 100,000 times farther away than the nebula!

Okay, I've got to show you one more picture of the nebula....



...no, make that two images. The nebula is called the Cat's Eye Nebula, and when you show two pictures of it side by side it really feels as if a cosmic kitten is looking back at you!





Ann