NGC 1291 is located about 33 million light-years away in the constellation Eridanus. It is what's known as a barred galaxy, because its central region is dominated by a long bar of stars (in the new image, the bar is within the blue circle and looks like the letter "S"). The bar formed early in the history of the galaxy. It churns material around, forcing stars and gas from their original circular orbits into large, non-circular, radial orbits. This creates resonances -- areas where gas is compressed and triggered to form new stars. Our own Milky Way galaxy has a bar, though not as prominent as the one in NGC 1291. Read more
NGC 1291 (also NGC 1269, ESO 301-2, IRAS 03154-4117, MCG -7-7-8 and PGC 12209) is a magnitude +9.39 face-on barred ring galaxy located 33 million light-years away in the constellation Eridanus. The galaxy is near the star Theta Eridani (Acamar).
The galaxy was discovered by Scottish astronomer James Dunlop using a homemade 9-foot 22.86 cm (9 inch) f/12 speculum Newtonian reflector at Paramatta, New South Wales, Australia, on the 2nd September 1826. The galaxy was rediscovered by John Herschel in November 1836 and relisted as NGC 1269.
Right Ascension 03h 17m 18.3s, Declination -41° 06' 26"
This galaxy was cited as an example of a "transitional galaxy" by NASA's Galaxy Evolution Explorer team in 2007. Read more
Title: Cool Dust in the Outer Ring of NGC 1291 Authors: J. L. Hinz, C. W. Engelbracht, R. Skibba, A. Crocker, J. Donovan Meyer, K. Sandstrom, F. Walter, E. Montiel, B. D. Johnson, L. Hunt, G. Aniano, L. Armus, D. Calzetti, D. A. Dale, B. Draine, M. Galametz, B. Groves, R. C. Kennicutt, S. E. Meidt, E. J. Murphy, F. Tabatabaei
We examine Herschel Space Observatory images of one nearby prototypical outer ring galaxy, NGC 1291, and show that the ring becomes more prominent at wavelengths longer than 160um. The mass of cool dust in the ring dominates the total dust mass of the galaxy, accounting for at least 70% of it. The temperature of the emitting dust in the ring (T=19.5±0.3K) is cooler than that of the inner galaxy (T=25.7±0.7K). We discuss several explanations for the difference in dust temperature, including age and density differences in the stellar populations of the ring versus the bulge.