Eta Carinae and the Keyhole Nebula
author: Anglo-Australian Observatory/David Malin Images/Novapix
reference: a-neb33-72006
Image Size 300 DPI: 40 * 51 cm
This wonderfully complex region at the heart of the NGC 3372 nebula was first described in detail by Sir John Herschel in 1838. He saw the bright circular shell visible in the upper part of the picture extending to the south to form a keyhole-shaped nebula. This luminous outline is no longer seen and the southern extension appears only as a dark dust cloud. It seems that the curious, explosively variable star Eta Carinae has enveloped itself in a cocoon of obscuring matter in the years since Herschel's observations and light from the star is no longer able to illuminate the rim of the dust cloud. The nebula thrown off by eta Car in Herschel's time has grown to the tiny orange nebula seen to the left of the dust cloud and is known as the Homunculus nebula.