A dark cloud of gas in the shape of a spider called Lupus 4 blocks out more-distant starsESO

A spider-shaped blob of gas and dust, Lupus 4, blots out background stars in an image taken by a telescope at ESO's La Silla Observatory in Chile. Framing the dark spider are stars glowing bright.

The spider will eventually dissipate to give way to brilliant starlight.

Clouds like these are where new stars form. At about 400 light year distance, the Lupus cloud and its star cluster around form the closest such groups to the sun and are a prime target for studying the adolescent stages of star lives, the ESO statement said.

Lupus 4 straddles the constellations of Lupus (The Wolf) and Norma (The Carpenter's Square).

Its neighbour Lupus 3 has been studied well with its 40 odd young stars formed over the last three million years. At present the source of energy for these stars is the heat from gravitational contraction. It is much later that fusion kicks off.

As mass estimates for Lupus 4 vary, scientists are not able to say how many stars will emerge from the dark spidery cloud.

Some say it can give rise to stars totalling 250 times the mass of sun while others predict 1600 solar masses. But most agree that Lupus 4 contains enough stuff to spawn many bright stars.

Astronomers think that the sun and most stars in the Milky Way started off in a star cluster similar to the one in which Lupus 4 is located.

ESO or the European Southern Observatory is a collaboration of 15 different countries, including Brazil, Austria, Spain and the United Kingdom. The organisation operates telescopes at three sites in the Atacama Desert of Chile.