Location
NGC 3109 is located about 1.3 megaparsecs (4.2 Mly) away, in the constellation Hydra. This puts it at the very outskirts of the Local Group. Its membership of the Local Group has been challenged, because it seems to be receding faster than estimates of the Local Group's escape velocity. It is distant enough from the largest members of the Local Group that it has not been tidally influenced by them.
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