Gigagalaxy Zoom

The Bug Nebula is one of the brightest and most extreme planetary nebulae known. Located about 3800 light-years away towards the constellation of Scorpius (the Scorpion), this nebula was expelled by a convulsing star located at its core, over 2200 years.

This beautiful cosmic butterfly has impressive walls of compressed gas laced with trailing strands and bubbling outflows, forming the bipolar lobes. The dense disc in the central region may have contributed to the origin of the hourglass structure of the nebula. A dark, dusty torus surrounds the inner nebula and its formation remains a mystery to astronomers.

Chemically, the composition of the Bug Nebula also makes it one of the more interesting cosmic clouds known. Earlier observations with the European Space Agency's Infrared Space Observatory, ISO, have shown that the dusty torus contains hydrocarbons, carbonates such as calcite, and water ice and iron as well. The presence of carbonates is intriguing because in the Solar System these compounds have offered evidence for liquid water in the past on bodies such as Mars. But its detection in nebulae such as the Bug Nebula, where no liquid water has existed, shows that other formation processes cannot be excluded.

At the centre of the Bug Nebula lies a super-hot, dying star. Despite a sizzling temperature of at least 220 000 degrees Celsius, making it one of the hottest stars known, the star itself has never been seen, as it is hidden by a shroud of dust, and is most likely as small as the Earth itself.

Astronomers have known of the Bug Nebula since at least 1888. However, Edward Emerson Barnard, an American astronomer — best known for the discovery of Barnard's star in 1916 — was the first to study and describe this peculiar object in 1907. It is also included in the New General Catalogue as the entry number 6302 (NGC 6302).