Hubble is still teaching us so many years later. Case in point: today the telescope team tweeted a beautiful shot of a barred spiral galaxy. This one is not new--it was discovered in 1784 by German-British astronomer William Herschel.
NGC 4394 is located about 55 million light years from Earth in the Virgo Cluster. It's in the constellation of Coma Berenices (Berenice's Hair).
What is a barred spiral galaxy? NASA explains:
At the center of NGC 4394 lies a region of ionized gas known as a low-ionization nuclear emission-line region (LINER). LINERs are active regions that display a characteristic set of emission lines in their spectra— mostly from weakly ionized atoms of oxygen, nitrogen and sulphur.
Explore the tweet to learn more: