B68, the Black Cloud

This photograph shows an unusual sky field in the Milky Way band. It is centred on one of the classical, dark globules, known as Barnard 68 (B68) after the American astronomer, Edward E. Barnard (1857 - 1923), who included it in a list of such objects, published in 1919. It appears as a compact, opaque and rather sharply defined object against a rich, background star field. Even on this image that registers many faint stars in the area, not a single foreground star is observed. This is a clear sign that this globule must be relatively nearby. Interstellar clouds consist of gas and dust, including many molecules, some of which contain carbon atoms (i.e. organic). For a long time considered to be "holes in the sky", molecular clouds are now known to be among the coolest objects in the Universe (the temperature is approx. 10 K, or -263 °C). Moreover, and most importantly, they are nurseries of stars and planets. It still remains a mystery how a dark cloud like Barnard 68 at some moment begins to contract and subsequently transforms itself into hydrogen-burning stars. However, deep images of these clouds, such as this one obtained by FORS1 on VLT ANTU, may provide important clues. This small cloud seems to be in its very earliest phase of collapse. It has a diameter of only 7 light-months (approx. 0.2 pc) and it is located at a distance of about 500 light-years (160 pc) towards the southern constellation Ophiuchus (The Serpent-holder). This three-colour composite was reproduced from one blue (B), one green-yellow (V) and one near-infrared (I) exposure that were obtained with VLT ANTU and FORS1 in the early morning of March 27, 1999. The field measures 6.8x6.8 arcmin 2. The image consists of 2048x2048 pixels, each measuring 0.20 arcsec; the "Full Resolution" version of the photo shows all of these. North is up and East is to the left. (See also ESO Press Release eso0102.)

Credit:

ESO

About the Image

Id:eso9924a
Type:Observation
Release date:30 April 1999
Related releases:eso9924
Size:1955 x 1953 px

About the Object

Name:B 68, Barnard 68, LDN 57
Type:• Milky Way : Nebula : Appearance : Dark : Bok Globule
• X - Nebulae
Distance:500 light years
Constellation:Ophiuchus

Image Formats

Large JPEG
2.4 MB
Screensize JPEG
540.4 KB

Wallpapers

1024x768
514.2 KB
1280x1024
842.6 KB
1600x1200
1.2 MB
1920x1200
1.4 MB
2048x1536
1.9 MB

Coordinates

Position (RA):17 22 38.23
Position (Dec):-23° 49' 34.69"
Field of view:6.53 x 6.52 arcminutes
Orientation:North is 0.1° right of vertical
View in WorldWide Telescope:
View in WorldWide Telescope

Colours & filters

BandWavelengthTelescope
Optical
B
445 nm Very Large Telescope
FORS1
Optical
V
547 nm Very Large Telescope
FORS1
Infrared
I
806 nm Very Large Telescope
FORS1

Also see our