“Nebulae” collection
Elephant's Trunk Nebula
IC 1396
The Elephant’s Trunk Nebula is 2,400 light-years away from us. The ionization source is the star in the bottom center, HD 206267. The “trunk” itself is an active star formation region. There is at least one young star there that is less than 100,000 years old. Unfortunately that star is out of reach for our equipment. However, two slightly older ones (1 million years) are visible in the central hole in the trunk.
Bubble Nebula
NGC 7635 / Sharpless 162 / Caldwell 11, NGC 7538, M52 / NGC 7654
This is an actual bubble - altough it is 7 light-years across. That is 1.5x the distance to the nearest star to us. The hot young star in the center of the bubble is shedding its outer layers (it is a Wolf-Rayet star, SAO 20575). While that mass is being blown away from the star by the stellar wind it is also excited by the intense radiation. The nearby molecular cloud is glowing for the same reason. This star is going to become a supernova in about 10-20 million years and will collapse into a black hole.
Iris Nebula
NGC 7023 / Caldwell 4
The Iris Nebula is a reflection nebula, which means it is made of dust and is illuminated by starlight (in the visible spectrum). In this case, by the bright star visible in the center. The nebula itself is very bright, just below the human eye’s perception threshold (which is about 10 photons hitting the same cell in a tenth of second). It is 6 light-years in diamater and is about 1,300 light-years away from Earth.
Pelican Nebula
IC 5070 & 5067
This beutiful star formation region is easy to find in the sky. Deneb, a magnitude 1.25 star, is just out frame (near the top left corner). The image is SHO palette (Sulphur/Hydrogen/Oxygen gas).
Heart Nebula
IC1805 / Melotte 15 / Collinder 26
This is the Heart Nebula (7,500 light-years away) and you see over 20,000 stars in this image. Some of the stars in this image are ~50x Sol masses but most are a lot smaller.
Pleiades
M45 / Seven Sisters / Kiʹmah
Kiʹmah is possibly a reference to Pleiades in Amos 5:8:
The One who made the Kiʹmah constellation and the Keʹsil constellation,
The One who turns deep shadow into morning,
The One who makes day as dark as night,
The One who summons the waters of the sea
To pour them out on the surface of the earth
—Jehovah is his name."