NGC 1309 is about 75,000 light-years across, and is about 3/4s the width of the Milky Way. Its shape is classified as SA(s)bc, meaning that it has moderately wound spiral arms and no ring.
Bright blue areas of star formation can be seen in the spiral arms, while the yellowish central nucleus contains older-population stars. NGC 1309 is one of over 200 members of the Eridanus Group of galaxies.[4]
Supernova 2002fk
SN 2002fk was discovered jointly by Reiki Kushida of the Yatsugatake South Base Observatory, Nagano Prefecture, Japan; and Jun-jie Wang and Yu-Lei Qiu of the Beijing Astronomical Observatory on 17 Sept 2002.[5] When it was discovered it was magnitude ~15.0; it was estimated to have reached maximum magnitude of ~13.0 before fading away. It was a Type Ia supernova (i.e., the progenitor star was white dwarf). White dwarfs are older stars that have used up almost all of their main fuel (the lighter elements such as hydrogen and helium). SN 2002fk's spectra showed no indications of hydrogen, helium or carbon; instead ionized calcium, silicon, iron and nickel were found.[6]
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Riess, Adam (Jul 2007). "The Final SHOE; Completing a Rich Cepheid Field in NGC 1309". Hubble Space Telescope Proposal ID #11329 (Cycle 16): 11329. Bibcode:2007hst..prop11329R.