NGC1365 The Great Barred Spiral Galaxy with CHI-1 & CHI-3

NGC 1365, also known as the Great Barred Spiral Galaxy, is a double-barred spiral galaxy located about 56 millions light--years away in the constellation Fornax.

Indeed, within the larger long bar stretching across the center of the galaxy appears to be a smaller bar that comprises the core, with an apparent size of about 50″ × 40″.

This second bar is more prominent in infrared images of the central region of the galaxy, and likely arises from a combination of dynamical instabilities of stellar orbits in the region, along with gravity, density waves, and the overall rotation of the disc. The inner bar structure likely rotates as a whole more rapidly than the larger long bar, creating the diagonal shape seen in images.The spiral arms extend in a wide curve north and south from the ends of the east-west bar and form an almost ring like Z-shaped halo.

The very high rate of star formation that reveals the general bluish color is explained by the presence of this huge bar (composed of old stars and dust) that connects the two spiral arms. By compressing the gas present, this bar triggers multiple stellar births in the arms of the galaxy.NGC 1365, including its two outer spiral arms, spreads over around 200,000 light-years.

Such galaxies are quite common (two thirds of spiral galaxies are barred according to recent estimates), and studying others can help astronomers understand our own galactic home.

I mixed data from the ASA RC1000 and the CDK24 telescopes in order to enhance a little bit core details. More data would have been useful to enhance the faint extensions of the spiral arms.

- CDK24 and FLI PL9000 (from 01/25/22 to 02/01/22) :

LRGB : 14-14-14-14 x 600s

- ASA RC1000 and FLI PL16803 (12/12:20) :

L : 7x300s