Solving The Mystery Of Nebulae

[ilan]

Solving The Mystery Of Nebulae In Astronomy - Part 1
Ethan Siegel, Forbes Magazine

An emission nebula found in the constellation of Orion, the Flame Nebula is lit up by one of the famous ‘belt’ stars. Image credit: ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit.

From ancient times, humanity realized there’s more to the night sky than stars.

Located just outside the Big Dipper, the objects M81 and M82 appear nebulous, but are in fact galaxies located far outside the Milky Way, containing billions of stars apiece. Image credit: Markus Schopfer under a c.c.-by-2.5 license.

Stellar assemblies, like clusters and galaxies, are plentiful, but aren’t real nebulae.

A section of the sky with many nebulous features around R Coronae Australis. Image credit: ESO.

[ilan]

Solving The Mystery Of Nebulae In Astronomy - Part 2
Ethan Siegel, Forbes Magazine

A true nebulae, is a diffuse, cloud-like object, resulting from gas within a galaxy.

A dark nebula images in the nebula NGC 281, by the Hubble Space Telescope. Image credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA); Acknowledgment: P. McCullough (STScI).

Dark nebulae – dusty, dense clouds of material — block incoming background light.

The dark cloud Barnard 68 blocks the background light from all the stars behind it. Data obtained with the 8.2-m VLT ANTU telescope and the multimode FORS1 instrument in March 1999. Image credit: ESO.

Many will form stars in the future, with their gas not having collapsed enough yet.

The reflection nebula NGC 1999. Image credit: NASA/ESA and the Hubble Heritage Team (STScI).

[Capt.Kangaroo]

Thanks ilan
Barnard 68 is just an evil looking dark patch.

[ilan]

Yes, it looks like the Void of all voids! I'm fascinated by nebulae. I find them pretty darned cool (in a non-temperature sense, of course).