There isn't a specific term for a small group of stars within a constellation. However, depending on the arrangement and characteristics of the stars, you could use these terms:

* Asterism: A recognizable pattern of stars, not necessarily part of an official constellation. Examples include the Big Dipper and Little Dipper, which are both part of Ursa Major and Ursa Minor, respectively.

* Star cluster: A group of stars that are gravitationally bound together. These can be either open clusters (loosely bound, often young) or globular clusters (tightly bound, containing older stars).

* Multiple star system: A group of two or more stars that orbit around each other. These can be binary stars, trinary stars, or even systems with more stars.

So, it really depends on the context and what you are referring to.