M57, the Ring Nebula

This is M57, the Ring Nebula. It's a planetary nebula, which means it's the remains of a "dead" star. The image was taken by amateur astronomers Randy and Betty Ivins, and their granddaughter Miranda.

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Amateur astronomy is a fairly popular pastime. It's fitting, to my mind, that the root word of "amateur" is "love", because clearly many amateur astronomers approach astronomy with a deep love and passion for the subject. As an example, I offer Randy and Betty Ivins, who with their granddaughter Miranda are a family of amateur astronomers with a long history of working with us at the Space Science Center. They're accomplished astro-photographers, obtaining beautiful images of astronomical objects with small telescopes, such as the lovely Ring Nebula image shown here.

A planetary nebula like the Ring was once a star no more than a few times the mass of our Sun (and probably a lot less). Such a star, at the end of its lifetime, will swell outward to a huge red giant star. After this, however, the star will lose most of its outer layers of gas, which expand outward in complex shells around the former star. The inner portions of the star dwindle down into a white dwarf, a mere cinder of a star glowing with leftover heat. The white dwarf is still hot enough to energize those shells of cast-off gas, creating fanciful glowing geometries in the resulting nebula.

The Ring Nebula, in particular, is a relatively close example - a mere two thousand light-years away or so. It was the second planetary nebula discovered, and was cataloged in 1779 by Charles Messier as the 57th non-stellar object Messier had discovered (thus the designation M57). We're probably looking down the axis of the nebula; seen from the side, it might have a more peanut-like shape. Most of the greenish light you see in this image comes from ionized oxygen atoms, which have been raised to an excited state after being bathed in the radiation from the white dwarf. If you look closely, you can see an outer ring of red from ionized hydrogen.

If you're looking for the Ring Nebula in the sky, you'll need a telescope with at least a 4-inch main lens or mirror, and fairly dark sky conditions. Find the constellation Lyra in the sky (currently somewhat above the eastern horizon at sunset). It's fairly easy to pick out, since its brightest star, Vega, is the second-brightest star you can see from the Northern hemisphere. Once you've found Vega, the rest of Lyra is a diamond-shaped arrangement nearby. M57 is between the second and third-brightest stars in Lyra (Beta and Gamma Lyrae), which are on the side of the diamond-shape furthest from Vega.

Photo credit: Randy and Betty Ivins and granddaughter Miranda.