Tuesday, May 4, 1999 Published at 16:02 GMT 17:02 UK
'Hole' in space spotted
No stars have been detected in the dark region
By BBC News Online Science Editor Dr David Whitehouse
Astronomers have spotted a "hole" in space. The region of the Milky Way they examined contains a myriad of stars, yet none can be seen over a large, black area.
The cause is a cloud of gas and dust in which there are no stars. Normally these are very difficult to see because stars in front of the clouds obscure the view from Earth.
This new image registers many faint stars, but not one in front of the cloud. This is a clear indication that the cloud is relatively near to Earth.
Cold and dark
Astronomers call these clouds "dark globules". This one is known as Barnard 68 after the American astronomer, Edward E. Barnard, who included it in a list of such objects, published in 1919.
Such dark globules are now known to be among the coolest objects in the Universe. Deep inside them, isolated from starlight, the temperature can drop to -263 degrees Celsius, just 10 degrees above absolute zero.
Dark globules are also the birthplaces of stars and planets. Gravity pulls the cloud in on itself sparking clumps of material into becoming stars.
It is still a mystery how objects like Barnard 68 start to contract. However, detailed images of the clouds may provide important clues. This one was obtained by the new telescopes at the European Southern Observatories' Paranal Observatory.
Barnard 68 seems to be in its very earliest phase of collapse. It has a diameter of seven light-months and it is located at a distance of about 500 light-years towards the southern constellation Ophiuchus (the serpent-holder).