Antlia B

Antila B
Antila B
	NGC 3109 (which Antila B is a satellite of) is located towards the far left
Observation data (J2000.0 epoch)
Constellation	Antila
Right ascension	09 48 56.1
Declination	-25 59 24
Group or cluster	NGC 3109 association
Characteristics
Type	Dwarf irregular
Other designations
	Ant B

Antlia B (also known as Ant 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.^[1] 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.^[2]

Stellar population

The stellar population of Antlia B is conpkex 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.^[1] Despite Antlia B being rich in gas to form new stars, there seems to be no evidence for active star formation within Antlia B.^[2]

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.^[2]

Discovery

The discovery of Antila B was from the Dark Energy Camera survey (DES).^[1]

Reference

^ ^a ^b ^c Sand, D. J.; Spekkens, K.; Crnojević, D.; Hargis, J. R.; Willman, B.; Strader, J.; Grillmair, C. J. (2015-08-07), Antlia B: A faint dwarf galaxy member of the NGC 3109 association, arXiv, doi:10.48550/arXiv.1508.01800, arXiv:1508.01800, retrieved 2025-07-12
^ ^a ^b ^c Hargis, Jonathan R.; Albers, S.; Crnojević, D.; Sand, D. J.; Weisz, D. R.; Carlin, J. L.; Spekkens, K.; Willman, B.; Peter, A. H. G. (2019-07-16), Hubble Space Telescope Imaging of Antlia B: Star Formation History and a New Tip of the Red Giant Branch Distance, arXiv, doi:10.48550/arXiv.1907.07185, arXiv:1907.07185, retrieved 2025-07-12

[:0-1] Sand, D. J.; Spekkens, K.; Crnojević, D.; Hargis, J. R.; Willman, B.; Strader, J.; Grillmair, C. J. (2015-08-07), Antlia B: A faint dwarf galaxy member of the NGC 3109 association, arXiv, doi:10.48550/arXiv.1508.01800, arXiv:1508.01800, retrieved 2025-07-12

[:1-2] Hargis, Jonathan R.; Albers, S.; Crnojević, D.; Sand, D. J.; Weisz, D. R.; Carlin, J. L.; Spekkens, K.; Willman, B.; Peter, A. H. G. (2019-07-16), Hubble Space Telescope Imaging of Antlia B: Star Formation History and a New Tip of the Red Giant Branch Distance, arXiv, doi:10.48550/arXiv.1907.07185, arXiv:1907.07185, retrieved 2025-07-12

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