About 10,000 years ago, a massive star in Cygnus, the swan, blew itself to bits. For a few days or weeks, it blazed as the brightest object in the night sky other than the Moon – bright enough to see even during the day. Today, its glowing remains are still visible – a colorful bubble that’s more than a hundred light-years across and growing.
The bubble is known as the Cygnus Loop. It’s a supernova remnant – the debris from a star that was about 20 times the mass of the Sun. After a short but brilliant life, the star could no longer produce nuclear energy in its core. The core collapsed, and the star’s outer layers exploded at a few percent of the speed of light.
As the bubble expands, it rams into surrounding clouds of gas and dust. That causes parts of the bubble to glow, forming the Veil Nebula and some other structures. Images reveal ribbons of gas and dust that intertwine like the strands of a rope. They shine in shades of red, blue, green, and other colors – the result of the elements they contain. Other parts of the Loop shine in wavelengths that are invisible to the human eye.
The Cygnus Loop is in the east-northeast at nightfall, to the lower right of Deneb, the bright star at the swan’s tail. The loop spans about six times the width of the full Moon. Small telescopes equipped with the right filters reveal some of the glowing filaments – the fading remnants of a stellar spectacle.
Script by Damond Benningfield