Meet NGC 1309. This picturesque spiral galaxy is located about 100-million light-years from Earth and can be found in the constellation Eridanus. Spanning a distance of 30,000 light-years, NGC 1309 is a nearly a third the size of our own Milky Way.
Officially, this galaxy’s shape is classified as SA(s)bc. That designation is designed to tell you a lot about the galaxy, in this case “S” refers to the spiral and “SA” refers to a galaxy without bars (so, a non-barred spiral galaxy). Next, galaxies are broken into those with rings, designated as “(r)” and those without rings which have the designation (S) – in addition, there is a transitionary designation of “(rs)”. Finally, the “bc” designation is seen because NGC 1309 is in a transitionary stage between a SAb and a SAc galaxy.
Back to this galaxy specifically, NGC 1309 has experience a couple of resent supernovae (or, rather, we’ve recently been able to observe these events – since they happened 100-million years ago!). Between these events and some Cepheid variable stars, NGC 1309 is used to help us understand and measure the expansion of the universe.