230813 - Sh2-162 "Bubble" nebula
|
click image to enlarge
|
ASTRO:
type=HII Region Emission nebula mag=10.0 const=Cassiopeia dist=7100 ly size=7 ly IMAGE: location=EB Driveway BrtlCls=4 moon=5% WnCr exposure=CMOS OSC, 80x360s (8.0h), Gain100 EQUIPMENT: camera=ZWO ASI2600MC-Pro optics=ES102 w1.7x eyepiece (projection mode), F(eff.)=1238mm, f/12.1 filter=Optolong L-eXtreme Duo NB mount=Celestron AVX guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acquisition=Stellarium, APT, PHD2 processing=PixInsight, RCAstro, PhotoshopCC, LrC |
|
Yes, massive stars can blow bubbles. The featured image shows perhaps the most famous of all star-bubbles, Sh2-162 (or NGC 7635, or Caldwell 11 (C11 for short)), is also known simply as The "Bubble" Nebula. Although it looks delicate, the 7 light-year diameter bubble offers evidence of violent processes at work. To the right of the Bubble's center is a hot, O-type star, several hundred thousand times more luminous, and some 45 times more massive than our Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The nebula lies in an H II region that is close to the open cluster Messier 52. The "bubble" was discovered in November 1787 by William Herschel. The intriguing nebula and associated cloud complex lie appx 7,100 light-years away toward the boastful and beautiful constellation Cassiopeia.
This sharp, tantalizing view of the cosmic bubble is a composite of 80 individual photographic exposures, each 360s (6m) in duration, collected over two nights, and "stacked" to form an image representing a total of 8.0 hours of integrated imaging time.
With an 8 or 10-inch (200 or 250 mm) telescope, the nebula is visible as an extremely faint and large shell around the star. The nearby 7th magnitude star below (with the artistic starburst added) hinders observation, but the nebula can be seen using averted vision. Using a 16 to 18-inch (410 to 460 mm) scope, one can see that the faint nebula is irregular, being elongated in the north-south direction.
This sharp, tantalizing view of the cosmic bubble is a composite of 80 individual photographic exposures, each 360s (6m) in duration, collected over two nights, and "stacked" to form an image representing a total of 8.0 hours of integrated imaging time.
With an 8 or 10-inch (200 or 250 mm) telescope, the nebula is visible as an extremely faint and large shell around the star. The nearby 7th magnitude star below (with the artistic starburst added) hinders observation, but the nebula can be seen using averted vision. Using a 16 to 18-inch (410 to 460 mm) scope, one can see that the faint nebula is irregular, being elongated in the north-south direction.