What is NGC 3109?
'''NGC 3109''' is a small barred [[Magellanic spiral|Magellanic type]] [[spiral galaxy]] or [[irregular galaxy]] around 4.34 million [[Light year|ly]] away in the direction of the constellation of [[Hydra (constellation)|Hydra]]. NGC 3109 is believed to be [[Galactic tide|tidally interacting]] with the [[dwarf elliptical galaxy]] [[Antlia Dwarf]].<ref>Grebel, Gallagher, Harbeck, p.7</ref> It was discovered by [[John Herschel]] on March 24, 1835 while he was in what is now [[South Africa]].<ref>{{Cite web|title=SEDS USA|url=https://seds.org/|access-date=2022-11-11|website=SEDS USA|language=en-US}}</ref> [[File:NGC_3109_2MASS.jpg|thumb|The Purple light in the photo shown is the galaxy.]] == Size and morphology == NGC 3109 is classified as a [[Magellanic Clouds|Magellanic]] type [[irregular galaxy]],<ref>{{Cite book|url=https://books.google.com/books?id=3gn5hS2zIkcC&pg=PA286|title=Stellar Astrophysics for the Local Group: VIII Canary Islands Winter School of Astrophysics|last1=Aparicio|first1=A.|last2=Herrero|first2=A.|last3=Sánchez|first3=F.|date=1998-06-13|publisher=Cambridge University Press|isbn=978-0-521-63255-3|language=en}}</ref> but it may in fact be a small [[spiral galaxy]]. If it is a spiral galaxy, it would be the smallest in the Local Group.<ref>{{Cite book|url=https://books.google.com/books?id=xAPX8UfT6qAC&q=ngc+3109&pg=PA123|title=The Evolution of Galaxies: II - Basic Building Blocks|last1=Sauvage|first1=Marc|last2=Stasinska|first2=Grazyna|last3=Schaerer|first3=D.|date=2002-07-31|publisher=Springer Science & Business Media|isbn=978-1-4020-0622-7|language=en}}</ref> NGC 3109 has a mass of about 2.3×10⁹ times the mass of the [[Sun]], of which 20% of the mass is in the form of neutral [[hydrogen]].<ref>{{Cite book|url=https://books.google.com/books?id=NfOwG3cyAGIC&pg=PA265|title=The Galaxies of the Local Group|last=Bergh|first=Sidney|date=2000-05-15|publisher=Cambridge University Press|isbn=978-1-139-42965-8|language=en}}</ref> It is oriented edge-on from our point of view, and may contain a [[Galactic