Galactic Nebula IC 4603
History
This reflection nebula and others in that region were discovered in 1882 by the American astronomer Edward Barnard. Dreyer added it in 1910 as IC 4603 to his second «Index Catalogue». Later in 1919 Barnard also discovered the dark nebulae B 42, B 44 and B 45. [239, 277, 315]
Physical Properties
The reflection nebula IC 4603 (LBN 1109) lies roughly in the center of the large area of nebula called Ophiuchus Molecular Cloud, which spans an area of about 4.5° × 6.5°. This also includes IC 4604, IC 4605, the Antares nebula vdB 107, Sharpless 2-9 and many dark clouds. The open cluster in the center is only visible in infrared light.
The Ophiuchus Molecular Cloud, also called Rho Ophiuchus Cloud, is an area with active star formation, which is one of the closest to us at a distance of only about 407 light years. X-ray and infrared observations revealed more than 300 young stars within the large cloud in the center. The age of these stars is estimated to be only 300,000 years - very young compared to the oldest stars in the universe, which are more than twelve billion years old. [460]
Finder Chart
The nebula IC 4603 is located in the constellation Ophiuchus (Serpent Bearer) about one degree south of the 5 mag star ρ Ophiuchi, or about two degrees north of the bright star Antares (α Scorpii) in the constellation Scorpius (Scorpio). The best observation time is April to August.
Visual Observation
Description pending ...