Sextans B

Sextans B, also known as UGC 5373, is an irregular dwarf galaxy located approximately 4.44 million light-years away in the constellation Sextans. It is a member of the Local Group, though it lies on the outskirts of the group and its membership is sometimes debated.

Sextans B has a diameter of roughly 5,000 light-years, making it considerably smaller and less massive than our Milky Way galaxy. It is characterized by a relatively low surface brightness and a sparse stellar population. The galaxy exhibits a significant amount of ongoing star formation, particularly in its central regions. These star-forming regions are rich in young, massive, blue stars.

The galaxy's chemical composition is also notable. Sextans B is metal-poor, meaning it has a lower abundance of elements heavier than hydrogen and helium compared to the Milky Way. This suggests that it has experienced fewer generations of star formation and less chemical enrichment.

Sextans B appears to be tidally interacting with the nearby dwarf galaxy Sextans A. While the nature of this interaction is not fully understood, evidence suggests that it may be influencing the star formation rates and morphology of both galaxies. The interaction is a subject of ongoing research.

Sextans B was discovered in 1966 by Sidney van den Bergh. Its faintness and diffuse nature make it a challenging object to observe. Despite its distance and low luminosity, Sextans B provides valuable insights into the formation and evolution of dwarf galaxies, particularly in the context of the Local Group.