Cosmic jets from a baby star

This image shows two jets of particles flying out from a newborn star in the Orion B molecular cloud, some 1,350 light years from Earth. Though the star itself is veiled by dust, its glow lights up the whole region.

When stars form within giant clouds of cool molecular hydrogen, some of the surrounding material collapses under gravity to form a rotating, flattened disk encircling the newborn star. Though planets may later congeal in the disk, at this early stage the protostar is feeding on the disk. Gas from the disk rains down onto the protostar and engorges it. Superheated material spills away and is shot outward from the star in opposite directions along an uncluttered escape route – the star’s rotation axis.

Shock fronts develop along the jets and heat the surrounding gas. The jets collide with the surrounding gas and dust and clear vast spaces, like a stream of water ploughing into a hill of sand. 

These shock fronts form tangled, knotted clumps of nebulosity and are collectively known as Herbig-Haro (HH) objects. The prominent HH object shown here is called HH 24.

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