similar age and composition.
because all the stars in a cluster are about the same age and distance from the Earth
It can be called a star cluster, an open cluster or an asterism.
The H-R diagram of a star cluster is missing the upper part of the main sequence
open cluster
globular cluster
star cluster
A star cluster is a cluster of stars, so clearly a star cluster must be larger.
Constellation or "asterism". The difference is that "constellations" are officially recognized by the International Astronomical Union, while an "asterism" is any other pattern or grouping of stars.
star cluster
because all the stars in a cluster are about the same age and distance from the Earth
A Star Cluster is a cluster of stars found within a galaxy or the intergalactic medium, and they don't usually have supermassive black hole centers or spiral arms. Star clusters contain around a thousand stars, compared to the Milky Way's 300 billion stars. In short, a galaxy is not classified as a star cluster.
A cluster or star cluster
A small group of stars is a cluster or a constellation of stars.
Binary Stars
Star cluster or Stellar cluster.
Star cluster or Stellar cluster.
It can be called a star cluster, an open cluster or an asterism.