Starship Asterisk*

Rings Around the Ring Nebula

Explanation: There is much more to the familiar Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra.

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Looks like a beautiful flower!

Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo.

Guest wrote: ↑Sun Jul 15, 2018 1:19 pm Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo.

It's not planar. Most likely it has a bipolar structure- a highly prolate spheroid or hourglass shape, which we're viewing fairly near its axis of symmetry.

Chris Peterson wrote: ↑Sun Jul 15, 2018 1:44 pm

Guest wrote: ↑Sun Jul 15, 2018 1:19 pm Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo.

It's not planar. Most likely it has a bipolar structure- a highly prolate spheroid or hourglass shape, which we're viewing fairly near its axis of symmetry.

So... is the pink “question mark”, in the central part of the image, actually material inside of the inner ring or is it much further away from the center and merely appears to be in the center due to our perspective? Is it, perhaps, more like the wisps we see on the periphery?

Tszabeau wrote: ↑Sun Jul 15, 2018 2:07 pm

Chris Peterson wrote: ↑Sun Jul 15, 2018 1:44 pm

Guest wrote: ↑Sun Jul 15, 2018 1:19 pm Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo.

It's not planar. Most likely it has a bipolar structure- a highly prolate spheroid or hourglass shape, which we're viewing fairly near its axis of symmetry.

So... is the pink “question mark”, in the central part of the image, actually material inside of the inner ring or is it much further away from the center and merely appears to be in the center due to our perspective? Is it, perhaps, more like the wisps we see on the periphery?

Hard to say. The distance any material is from the axis of symmetry depends on the shape of the bipolar structure, the time it was ejected, and the speed it was ejected. Disentangling those things is difficult. We're looking at a structure that is only about 1500 years old, so the material is moving quickly- maybe fast enough to see changes in high resolution images made several years apart. And since we're around 30° off the axis of symmetry, we might be able to measure some speeds by looking at Doppler shift. And the narrowband data provides information about composition, which carries clues to ejection time and speed. So it's likely there's enough information available to make some educated guesses about the position of certain elements in the 3D structure, but I imagine there's still going to be a good deal of uncertainty in many cases.

Wait a minute! Surely right at the center there it is a map of Earth (viewed from far above the north pole)?

Guest wrote: ↑Sun Jul 15, 2018 1:19 pm Are we looking 'down' on a plane of debris based on rotation of the star, or are we looking at a sphere of debris and just see the thicker edges based on our perspective. Great photo.

If you want to learn how we model this nebula from the observations, see:

http://iopscience.iop.org/article/10.1086/521823/pdf

neufer wrote: ↑Sun Jul 15, 2018 12:04 pm

Click to play embedded YouTube video.

The BEST Martha Stewart show I ever saw was the one with Cookie Monster as the guest! He should have got an Emmy