Rho Ophiuchi Nebula (IC 4604)

IC 4604
IC 4604: Reflection nebula around star ρ Ophiuchi. Crop from DSS [147]

Object Description

The reflection nebula IC 4604 (LBN 1111) belongs together with IC 4603, IC 4605, the Antares nebula vdB 107, Sharpless 2-9 and many dark clouds to a large area of nebula, the Ophiuchus Molecular Cloud. Its center is about one degree south of the star ρ Ophiuchi, is surrounded by dense dust and is only visible in infrared images. The IC numbers were discovered in 1882 by the American astronomer Edward Barnard, who also recorded the dark clouds B 42, B 44 and B 45. [196, 239, 270, 277]

Rho Ophiuchi cloud complex
Rho Ophiuchi cloud complex: In visible light (DSS) and Infrared (WISE) [147]

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]

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
DesignationIC 4604
TypeRN+*
Right Ascension16h 25m 33.0s
Declination-23° 26' 36"
Diameter60 × 50 arcmin
Metric Distance0.120 kpc
Dreyer Descriptionρ Ophiuchi in eL neb
Identification, RemarksLBN 1112, ESO 517-*N3, CED 131B, Rho Oph nebula
Ophiuchus Molecular Cloud
Ophiuchus Molecular Cloud: Star forming region with open cluster Collinder 302 with Ophiuchus molecular cloud (Antares Nebula vdB 107, nebula IC 4603, ρ Ophiuchi nebula IC 4604, nebula IC 4605, Sharpless 2-9, many dark clouds), plus globular clusters M 4 and NGC 6144. North is left; Canon EOS 20Da, zoom lens 131 mm f:5.6 ; 145 min @ ISO 1600; Astrofarm Tivoli, Namibia, 1345 m ü. M.; © 5. 6. 2011 Eduard von Bergen, Hansjörg Wälchli

Finder Chart

The nebula IC 4604 is located in the constellation Ophiuchus (Serpent Bearer) and as the name «Rho Ophiuchi nebula» suggests at the 5 mag star ρ Ophiuchi, around three degrees north of the bright star Antares (α Scorpii) in the constellation Scorpius (Scorpio). The best observation time is April to August.

Chart Rho Ophiuchi Nebula (IC 4604)
Rho Ophiuchi Nebula (IC 4604) in constellation Ophiuchus. Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

More Objects Nearby (±15°)

References

147Aladin Lite; aladin.u-strasbg.fr/AladinLite (2020-12-23)
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
239«On the dark markings of the sky, with a catalogue of 182 such objects» Barnard, E. E.; Astrophysical Journal, 49, 1-24 (1919); DOI:10.1086/142439; Bibcode:1919ApJ....49....1B
270«Catalogue of Bright Nebulae» Lynds, Beverly T.; Astrophysical Journal Supplement, vol. 12, p.163 (1965); DOI:10.1086/190123
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
460Young Stars in Their Baby Blanket of Dust; nasa.gov/mission_pages/spitzer/multimedia/20080211.html (2021-12-30)