The NASA/ESA Hubble Space Telescope's picture of the barred spiral galaxy NGC 1073, which is found in the constellation of Cetus (The Sea Monster). Our own galaxy, the Milky Way, is a similar barred spiral, and the study of galaxies such as NGC 1073 helps astronomers learn more about our celestial home.
Most spiral galaxies in the Universe have a bar structure in their
centre, and Hubble's image of NGC 1073 offers a particularly clear
view of one of these. Galaxies' star-filled bars are thought to emerge
as gravitational density waves funnel gas toward the galactic centre,
supplying the material to create new stars. The transport of gas can
also feed the supermassive black holes that lurk in the centres of
almost every galaxy.
Some astronomers have suggested that the formation of a central bar-like structure might signal a spiral galaxy's passage from intense star-formation into adulthood, as the bars turn up more often in galaxies full of older, red stars than younger, blue stars. This storyline would also account for the observation that in the early Universe, only around a fifth of spiral galaxies contained bars, while more than two thirds do in the more modern cosmos.
Credit: NASA/ESA/Hubble Space Telescope