RCW 58-Wolf Rayet Bubble

Imagine traveling to a star about 100 times as massive as our Sun, a million times more luminous, and with 30 times the surface temperature. Such stars exist, and some are known as Wolf Rayet (WR) stars, named after French astronomers Charles Wolf and Georges Rayet. The central star in this image is WR 40 which is located toward the constellation of Carina. Stars like WR 40 live fast and die young in comparison with the Sun. They quickly exhaust their core hydrogen supply, move on to fusing heavier core elements, and expand while ejecting their outer layers via high stellar winds. In this case, the central star WR 40 ejects the atmosphere at a speed of nearly 100 kilometers per second, and these outer layers have become the expanding oval-shaped nebula RCW 58.

This just looks like you can hear it sizzling! RCW58, an E type nebula, is a Wolf Rayet Bubble formed by the ejecta from WR 40, the central star in the image. These three-dimensional bubbles appear as a ring in two dimensions, as seen in this image and represent the stellar ejecta contained in a windblown bubble. The are several similar WR ring nebulae are known including: MI-67, RCW104, RCW78, NGC3199, NGC6888.

H alpha and OIII emissions from eight of the most well defined Wolf Rayet ring nebulae in the Galaxy reveal that in many cases the outermost edge of the OIII emission leads the H alpha emission. This suggests that these offsets, when present, are due to the shock from the Wolf Rayet bubble expanding into the circumstellar envelope.

Imaged in LRGB on our PlaneWave CDK 1000 and CDK 700 at Observatorio El Sauce, Chile. Image Processing: Mark Hanson and Mike Selby

Enjoy, Mark and Mike