Cocoons for Young Stars (2) . . .

The following image shows young stars in the Orion Nebula, which is about 1500 light years away in the sword of Orion.

The young stars are still surrounded by a cocoon of gas and dust called a proplyd or "protoplanetary disk." The teardrop shapes are caused by gas being eroded away by radiation from the hot young stars in the nebula. This animation zooms in on a protoplanetary disk in Orion.

The adjacent IR image from the 8.2 meter telescope of the European Southern Observatory shows a very young open cluster in which the stars are still immersed in the dust from which they were born. This cluster, designated RCW38, is about 5000 light years away in the constellation Vela.

When we see most open clusters we don't see so much dust because the stars have had time to move away from the nebula in which they formed and to disperse the dust with radiation pressure. In this case the stars are so young that they are still hiding in the dust. In visible light they would be mostly obscured by the dust, but IR penetrates the dust much better and allows the open cluster to be imaged