A group of astronomers using NASA´s Hubble Space Telescope observed the death of a low mass star, equivalent to the sun. The image taken showed the transformation of the star from a red giant star to a planetary nebula, and the ejection of gas and dust to the surrounding space. The gas spread out in opposite direction from the central part of the star at speeds that surpass the million km/h. this is one of the rare cases where astronomers have captured the transition of the final days of a star.
Calabash (Rotten Egg) Nebula
Calabash nebula (rotten egg nebula) is a protoplaneary nebula 1.4 light years long and which lies at approximately 5,000 light years away from the earth in the direction of the constellation Puppis in the southern hemisphere and is a member of the open cluster Messier 46.
The name rotten egg nebula stems from its large amounts of sulfur. The densest regions of the nebula is the recently ejected material from the central part of the nebula, which is accelerated at speeds of over 1.5 million km/h in opposite directions. Most of the star´s mass is contained within this region.
Messier 46
This is an open cluster of stars in the constellation Puppis with approximately 500 stars. It lies at approximately 5,500 light years away from the earth. Although the planetary nebula NGC 2438 lies within the cluster, it does not follow the cluster´s radial velocity, so it is not related to it. On the other hand, the Calabash nebula shares the same radial velocity and motion of Messier 46; it lies also at the same distance as seen from earth; therefore, it’s considered as a member of the open cluster of stars.
Evolving into a planetary nebula
Astronomers rarely are able to observe a star during its evolution due that, in astronomical terms, the event occurs within thousands or even millions of years. The Calabash nebula is predicted to evolve into a fully planetary nebula over some thousands of years. This nebula, also known as the Rotten Egg Nebula, derives its name from its large contents of sulphur, which when mixed with certain elements, smells closely similar to a rotten egg.
