Rotten Egg Nebula

The Rotten Egg Nebula is a red giant star called OH231.8+4.2 going through its death throes, dramatically transforming into a planetary nebula. So much dust has been cast off and now surrounds the star that it cannot be seen directly, only the starlight reflected off the dust can be observed. The flow of gas is very fast, with a velocity of up to 700 000 km/h.

Many unusual molecules have been found in the gas around this star, including many containing sulphur, such as hydrogen sulphide and sulphur dioxide. These sulphur compounds are believed to be produced in the shock waves passing through the gas. Because of the large amount of sulphur compounds, this object has earned the nickname The Rotten Egg.