Title image: © ESA/Hubble/NASA
Hubble just took the most detailed image yet of the eerie and mysterious Ghost Nebula. (Watch the video at the footer of the article.)
Some 550 light-years away from our humble little planet lives IC 63 – the Ghost Nebula. Found in the constellation of Cassiopeia, the nebula is unique in that it is classified as both a reflection nebula and an emission nebula. It is reflecting the light of its gigantic neighbor, the star Gamma Cassiopeiaea – and it is also releasing hydrogen-alpha radiation.
Named after the vain queen of Greek mythology, Cassiopeia used to be known as Cassiopeia’s Chair. In the 1930s, the International Astronomical Union gave this constellation the official name of Cassiopeia the Queen. Cassiopeiae forms a “an easy-to-see, slightly stretched-out “W” shape in the heavens, with the central point of the W holding the magnificent Gamma Cassiopeiae.
Gamma Cassiopeiae is seriously a superstar amongst stars – a blue-white subgiant that is surrounded by a gaseous disc. According to the European Space Agency (ESA), the star is 19 times more massive and 65 000 times brighter than our Sun. “It also rotates at the incredible speed of 1.6 million kilometres per hour — more than 200 times faster than our parent star,” notes ESA. “This frenzied rotation gives it a squashed appearance. The fast rotation causes eruptions of mass from the star into a surrounding disk. This mass loss is related to the observed brightness variations.” Drama much?
As for our little Ghost Nebula, its hydrogen is being bombarded with ultraviolet radiation from Gamma Cassiopeiae, causing its electrons to gain energy which they later release as hydrogen-alpha radiation, explains ESA. Those emissions account for the red in the image; the blue is light from Gamma Cassiopeiae that is being reflected by dust particles in the nebula. Isn’t she extraordinary?
The image above was taken from above Earth’s atmosphere by the Hubble Space Telescope – it is likely the most detailed image that has ever been taken of IC 63.
While this gorgeous nebula is ultimately dissipating thanks to the ultraviolet radiation from Gamma Cassiopeiae, there is still all kinds of other activity going on (well, 550 light-years ago at least) in the much larger nebulous region surrounding Gamma Cassiopeiae.
“This region is best seen from the Northern Hemisphere during autumn and winter,” writes ESA. “Though it is high in the sky and visible all year round from Europe, it is very dim, so observing it requires a fairly large telescope and dark skies.”
Or, you can just watch this video, which starts here at home with the night sky and then flies you through space right smack into the midst of the ghost of Cassiopeia. The world is truly a wonder…