The Helix Nebula in the Aquarius constellation, located some 700 light-years away from Earth, was just observed by the piercing infrared gaze of the VISTA telescope at the Paranal Observatory in Chile. Some have referred to the images as the Eye of Sauron, from JRR Tolkien’s Lord of the Rings.
The images reveal cold gas that is normally hidden from view among the warmer, star-lit material. Helix’s central star was once like Sol, but its outer layers of gas and dust have sloughed off. The planetary nebula scatters light in the visible spectrum, which is why it seems to emit a bluish glare.
The VISTA telescope, with its 4.1 meter (13.4 ft) mirror, peered inside the nebula on the infrared light wavelength, which is invisible to the naked eye. The images that were released today show that the central region of gas extends at least 4 light-years around, instead of the 2 light-years which was the previous estimate. The images also show the distant stars and galaxies hiding behind the nebula.
The cometary knots, filaments of material at the periphery, which are basically cooler strands of gas, are each as long as the Solar System is wide. Astronomers suspect that the intense radiation from the dying central star carves out such knots, but they are unaware of the exact origins.