Pronunciation: [ɡɹˈuːp ɒv stˈɑː] (IPA) 
The spelling of the phrase "group of star" is quite straightforward. "Group" is spelled as [ɡruːp], with a long "u" sound and a silent "p" at the end. "Of" is spelled as [ʌv], with a short "u" sound and a silent "f" at the end. "Star" is spelled as [stɑːr], with a long "a" sound and a silent "r" at the end. When combined, the phrase becomes [ɡruːp ʌv stɑːr].
A group of stars refers to a collection or cluster of celestial objects known as stars, bound together by the force of gravity. Stars are luminous celestial bodies composed of hot, glowing gases such as hydrogen and helium. Often, stars form in vast interstellar clouds known as nebulae and then gravitationally come together in groups.
These groups of stars can vary in size and density, ranging from a few stars to thousands or even millions of stars in a single group. They can take various forms, including open clusters, globular clusters, and stellar associations, each with distinct characteristics.
Open clusters are relatively young groups of stars held together by both their mutual gravitational attraction and their common origin from the same molecular clouds. These clusters typically contain a few hundred stars that are loosely bound and easily separable from the surrounding space.
On the other hand, globular clusters are tightly bound spherical formations containing thousands to millions of stars that are much older than open clusters. They are typically found orbiting around galaxies, concentrated towards the galactic center, and are more compact and dense than open clusters.
Stellar associations are relatively loose groups of similar-aged and similar-sized stars that are not gravitationally bound. They often arise from the fragmentation of a molecular cloud, sharing a common motion and being in close proximity to each other.
The study of groups of stars, their formation, dynamics, and properties falls under the domain of astrophysics and stellar astronomy, providing valuable insights into the life cycles and behaviors of stars within the universe.
