Topsy Turvy Galaxy

NGC 1313, also nicknamed the Topsy Turvy Galaxy, was first identified by Scottish astronomer James Dunlop on September 27, 1826. It is categorized as a field galaxy and an irregular galaxy, boasting a diameter of roughly 50,000 light-years, approximately half the size of our own Milky Way.

Situated within the Virgo Supercluster, NGC 1313 harbors an unusual celestial object discovered in 2007, identified as [HC2007] 31, a rare WO star with a spectral type of WO3. Notably, its absolute magnitude is exceptionally high at about -5, typically uncommon for a single WO star, suggesting it may be part of a binary system or a small stellar association.

Additionally, NGC 1313 has been the site of two observed supernovae: SN 1962M (a type II supernova with a magnitude of 11.7) and SN 1978K (also type II, with a magnitude of 16).

NGC 1313 possesses a remarkably irregular shape, with its axis of rotation deviating from its center. This peculiarity is accompanied by vigorous starburst activity and the presence of associated supershells. The galaxy is characterized by scattered patches of intense star formation, contributing to its rugged appearance. These features are likely consequences of a previous galactic collision, although NGC 1313 appears to exist in isolation without immediate neighbors, leaving uncertainty regarding whether it absorbed a smaller companion in the past.

Throughout the galaxy, young open clusters disperse their constituent stars into the surrounding space due to gravitational forces. NGC 1313 bears a resemblance to the Magellanic Clouds and harbors two ultraluminous X-ray sources known as NGC 1313 X-1 and X-2. Notably, NGC 1313 X-1 is recognized as a rare intermediate-mass black hole.