What is a star group enlongated in shape?

A star group that is elongated in shape is often referred to as a stellar stream or a tidal stream. These structures form when gravitational interactions, such as those between galaxies, disrupt star clusters or dwarf galaxies, causing their stars to spread out along a narrow, elongated path. This can result in a visible trail of stars that can stretch across a significant region of space, often revealing the history and dynamics of the interactions that created them. Stellar streams can provide valuable insights into the formation and evolution of galaxies.