Daily Archives: February 8, 2015

Rho Ophiuchi cloud complex

8февThe Rho Ophiuchi cloud complex is a dark nebula of gas and dust that is located 1° south of the star ρ Ophiuchi of the constellation Ophiuchus. At an estimated distance of 131 ± 3 parsecs, this cloud is one of the closest star-forming regions to the Solar System.

This cloud covers an angular area of 4.5° × 6.5° on the celestial sphere. It consists of two major regions of dense gas and dust. The first contains a star-forming cloud (L1688) and two filaments (L1709 and L1755), while the second has a star-forming region (L1689) and a filament (L1712–L1729). These filaments extend up to 10–17.5 parsecs in length and can be as narrow as 0.24 parsecs in width. Some of the structures within the complex appear to be the result of a shock front passing through the clouds from the direction of the neighboring Sco OB2 association.

Temperatures of the clouds range from 13–22 K, and there is a total of about 3,000 times the mass of the Sun in material. Over half of the mass of the complex is concentrated around the L1688 cloud, and this is the most active star-forming region. There are embedded infrared sources within the complex. A total of 425 infrared sources have been detected near the L1688 cloud. These are presumed to be young stellar objects, including 16 classified as protostars, 123 T Tauri stars with dense circumstellar disks, and 77 weaker T Tauri stars with thinner disks. The last two categories of stars have estimated ages ranging from 100,000 to a million years.

Imaging telescopes or lenses: Canon EF 200mm f/2.8
Imaging cameras: Canon EOS 450D / Digital Rebel XSi / Kiss X2
Mounts: Vixen New Atlux
Filters: Astronomik CLS Clip-Filter
Resolution: 1024×678
Dates: June 13, 2010
Frames: 21×90″ bin 1×1
Integration: 0.5 hours
Avg. Moon age: 0.57 days
Avg. Moon phase: 0.37%
RA center: 247.008 degrees
DEC center: -23.507 degrees
Pixel scale: 22.741 arcsec/pixel
Orientation: -89.782 degrees
Field radius: 3.880 degrees
Locations: Marmaris, None
Author: bilgebay