NGC 3109

"NGC 3109 is a small barred Magellanic type spiral or irregular galaxy around 4.35 Mly away in the direction of the constellation of Hydra. It was discovered by John Herschel on March 24, 1835.

NGC 3109 is classified as a Magellanic type irregular galaxy, but it may in fact be a small spiral galaxy.

-It has an isophotal diameter approximately 41,700 light-years across,

-It is oriented edge-on from our point of view, and may contain a disk and a halo. The disk appears to be composed of stars of all ages, whereas the halo contains only very old and metal-poor stars. NGC 3109 does not appear to possess a galactic nucleus.

It is one of the most metal-poor star-forming galaxies in the Local group. NGC 3109 seems to contain an unusually large number of planetary nebulae for its luminosity. It also contains a substantial amount of dark matter.

NGC 3109 has two satellite galaxies, the Antlia Dwarf and Antlia B."(Wikipedia)