Antlia B

Antlia B is a faint dwarf irregular satellite galaxy located around 72 kiloparsecs from NGC 3109, a small irregular galaxy located 4.3 million light years from Earth at the edge of the local group. Antila B has a complex mixture of old red giant branch stars over 10 billion years old and young blue stars only a few hundred years old. Despite Antlia B being rich in gas, Antlia B shows no evidence of active star formation.

Stellar population

The stellar population of Antlia B is composed of prominent old, metal-poor red giant branch stars with ages greater than 10 billion years and young blue stars somewhere between 200-400 million years old. Despite Antlia B being rich in gas to form new stars, there seems to be no evidence for active star formation within Antlia B.

Stellar history

The history of star formation in Antlia B shows that there was relatively constant stellar mass growth for the first ~10-11 billion years of its history and then almost no growth for the last ~2-3 billion years.

Discovery

The discovery of Antila B was from the Dark Energy Camera survey.