“Star Clusters” collection
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.
M53
NGC 5024
This globular cluster was discovered in 1775, but it is a truly ancient object, 12.6 billion years old, only 1 billion years younger than the Universe itself. Another fact that makes it outstanding is that there are many first-generation stars in this cluster. As in, they were not formed from matter generated by previous stars, but are the first concentrations of mass.
Double Cluster
h Persei & χ Persei / Caldwell 14 / NGC 869 & 884
Two young star clusters about 7,500 light years from us. They reside in the Perseus arm of the Milky Way, while we are living in the Orion arm. So looking at the Double cluster you are looking through our local spiral arm into the neighbouring arm outward from the galactic center. Interestingly they are speeding towards us at 140,000 km/h.
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."
M3
NGC 5272
The M3 globular cluster is one of the largest and brightest in the Milky Way. This ancient, 11.4 billion years old cluster is made up of half a million stars and thousands are visible in this picture. It is located 32,600 light-years away from Earth and is quite isolated from the rest of our galaxy because it is ~40° above the galactic plane.