APOD 21: A HALO FOR NGC 6164

2014 May 22

The emission nebula of NGC 6164 was created by a rare, hot, luminous O-type star, about 40 times as massive as the Sun. As the star is about 4 million years old, in another 3-4 million years the massive star will end its life in a supernova explosion. The nebula itself has bipolar symmetry , making it similar in appearance to planetary nebula - the gaseous shrouds surrounding the dying sun-like stars. Similar to planetary nebulae, NGC 6164 is found to have an extensive, faint halo, revealed in the deep telescopic image. This halo is most likely a result of an earlier active phase in the O star. The landscape is composite of extensive narrow-band image data, highlighting glowing atomic hydrogen in red and blue hues.