What is a nebula?
Dust. More scientifically, an interstellar cloud of dust and ionized gases. There are nebulae which are remnants of dead or dying stars, and nebulae which are forming new stars.
From dead or dying stars, there are two types of nebulae. One is supernova remnants. A notable example is the Veil nebula in Cygnus. It's not very visible by telescopes unless you have an Oxygen III filter. Then it appears as a greenish smudge in the eyepiece. We don't get the spectacular color the computers add in for the Hubble shots.
The second type from a dying star is the planetary nebula. The final stages of a main sequence star's life (our own Sun will die this way), it's shedding off its gases. Prime examples are the Ring nebula and the Dumbbell nebula.
The Ring appears as named and has a blue tint in eyepieces. Bigger telescopes which gather more light can show a star in the center of the nebula. It's in the Lyra constellation near Cygnus.
The Dumbbell is in the Cygnus constellation. It's a planetary nebula sideways. It appears with a greenish tint in the eyepiece. This photo taken by the camera attached to the 24" Cassegrain at Pine Mountain Observatory.
Prominent examples of nebulae forming new stars are the Orion nebula (in Orion's sword--the closest region of star formation to Earth) and the Lagoon nebula near Sagittarius. Since Orion is a winter constellation, the Lagoon is what I usually show to visitors at the observatory in the summer. The Orion nebula is below it. Both photos also taken at PMO.
There are also H II Region nebulae which include diffuse, bright and reflection nebulae. By definition they contain no well-defined boundaries, which actually applies to almost all nebulae. A nebula can have more than one classification. It can have dark and bright regions, be forming new stars and parts of it may reflect light.
The Swan nebula, also know as Omega, Checkmark, Lobster and Horsehead nebula is a group of newly formed stars. It's also a nebula we often show in the summer, located near Sagittarius.
My favorite nebula is Orion. But since it isn't visible most of the summer (unless I stay up until dawn), the Lagoon is my favorite summer nebula.
OK, my X, Xploring, is really lame. The observatory opens in one month though. So, I'm Xcited, too. It's possible one or more of the nebula contain Xenon, and I'm sure they've all been looked at by X-ray telescopes. There we go, PaX.
The Backworlds Blog Tour May 7th, 2012
If you'd like to help me get the word out of my next release, The Backworlds, I'd be most appreciative. Sign up below for the launch party, and I'll see to it you're emailed what you need to post up.Will give you a break when AtoZ ends. Post up any time the week of May 7th. And you don't have to visit anybody. The Linky link is so I can be organized.
Sign up is HERE
Do you have a favorite nebula? Is my X lamer than yours? Go ahead, you can say yes.
