Thackeray's Globules in IC 2944

 

clic for 36% size 1443 x 962 (363 kB)

clic here for 60% size 2342 x 1603 (762 kB)


About this Image

The emission nebula IC 2944 also named Running Chicken Nebula is housing interesting small scale structures.
These are known as the famous Thackeray's globules - small dark clouds made of gas and dust that are typically condensing to form a star - here visible in the center of this image embedded in a glowing H II region.

These are often also named as Bok globules, named after the astronomer Bart Bok. Bok globules typically are dark clouds of dense dust and gas in which star formation takes place. Bok globules are found within H II regions, and typically have a mass of about 1050 solar masses contained within a region about a light year across. They contain molecular hydrogen, carbon oxides and helium, and around 1% of silicate dust. Bok globules most commonly result in the formation of double or multiple star systems.
Powerful ultraviolet radiation from the luminous, massive nearby stars is eroding the globules continuously. Bok globules are still a subject of intense research. Known to be some of the coldest objects in the natural universe (as cold as 3 kelvins), their structure and density remains somewhat a mystery.

The distance to IC 2944 is approx. 7000 light years.
North is to the right.

Find more information and a Hubble image here: 1.

Below you find a close-up on the globules in 50/100% size.

clic for 80% size 960 x 956 (171 kB)


Technical Details

Optics

20 " Keller cassegrain in corrected secondary focus at f/9

Mount Liebscher GEM
Camera SBIG STL-11000M at -25C, 8-pos STL filter wheel
Filters Baader RGB, H-alpha, (7 nm)
Date May 03, 2008.
Location IAS/Hakos Namibia
Sky Conditions dark skies, raw FWHM Ha: 1.6-1.9", raw FWHM RGB: 1.8-2.1"
temperature 10-15 C,
Exposure R:G:B = 30:30:30 minutes (10-minute sub-exposures); synthetic luminance used;
Ha: 3 x 30 min subexposures
Programs used Maxim DL 4.5
CCDStack
Photoshop CS3