This newly launched picture from the XMM-Newton satellite tv for pc reveals Abell 78 – the second born-again planetary nebula found.
Beneath the vivid hues of this eye-shaped cloud, named Abell 78, a story of stellar life and demise is unfolding. On the middle of the nebula, a dying star – not not like our Solar – which shed its outer layers on its option to oblivion has, for a quick time frame, come again to echo its previous glory.
Releasing their outer shells is the standard destiny for any star with a mass of 0.8–8 instances that of the Solar. Having exhausted the nuclear gas of their cores after burning for billions of years, these stars collapse to change into dense, sizzling white dwarf stars. Round them, the ejected materials strikes the ambient fuel and mud, creating stunning clouds often known as ‘planetary nebulas’. This curious title was adopted by 18th-century astronomers who found these ‘puffing’ stars and thought their spherical form just like that of planets.
Nonetheless, the resurgence to life seen on this picture is an distinctive occasion for a planetary nebula. Solely a handful of such born-again stars have been found, and right here the intricate form of the cloud’s glowing materials provides away its turbulent historical past.
Though nuclear burning of hydrogen and helium had ceased within the core of the dying star, inflicting it to break down beneath its personal weight and its envelope to broaden right into a bubble, a few of the star’s outer layers turned so dense that fusion of helium resumed there.
The renewed nuclear exercise triggered one other, a lot sooner wind, blowing extra materials away. The interaction between previous and new outflows has formed the cloud’s complicated construction, together with the radial filaments that may be seen streaming from the collapsing star on the middle.
The interplay between sluggish and quick winds gusting within the atmosphere of Abell 78 heated the fuel to over one million levels, making it shine brightly in X-rays. Astronomers detected this sizzling fuel with ESA’s XMM-Newton area observatory, revealing placing similarities with one other born-again planetary nebula, Abell 30.
This three-color picture combines X-ray information collected in 2013 by XMM-Newton (blue) with optical observations obtained utilizing two particular filters that reveal the glow of oxygen (inexperienced) and helium (purple). The optical information have been gathered in 2014 with the Andalusian Faint Object Spectrograph and Digicam on the Nordic Optical Telescope on La Palma, within the Canary Islands. A study of the X-ray emission from Abell 78 is presented in a paper by J.A. Toalá et al. 2015.
Publication: J. A. Toalá, et al., “The born-again planetary nebula A78: an X-ray twin of A30,” 2015, ApJ, 799, 67; doi:10.1088/0004-637X/799/1/67
Credit score: ESA/XMM-Newton/J.A. Toalá et al. 2015