Stars die in fire and anger.
They tremble and tremble and let their bowels burst into space; when the star explodes and the violence is over, a beautiful glowing cloud of star guts remains.
Such an event created the Veil Nebula, a gossamer piece of a larger supernova remnant called the Cygnus loop, formed when a star 20 times the mass of the Sun went supernova about 10,000 years ago.
If you love space photos (and which science buff doesn’t?) You’ve probably seen it – the Hubble Space Telescope released a spectacular image in 2015, taken with its Wide Field Camera 3 instrument, a rainbow of filaments stretching across the darkness of space.
Now researchers have reprocessed that data using new techniques, bringing out finer details in the gas wires.
(ESA / Hubble & NASA, Z. Levay)
Located about 2,100 light-years away and about 110 light-years in length, the Veil Nebula is believed to have been formed by a powerful stellar wind emitted before the star exploded.
The wind penetrated the gas already ejected by the dying star and hollowed out cavities. When the supernova shock wave enters this region, it interacts with the walls of the cavity, shocking and activating the gas in it, creating the complex, thread-like structure of the veil.
The new image (top) and the 2015 image (bottom). (ESA / Hubble & NASA, Z. Levay; NASA, ESA, Hubble Heritage Team)
Images like these aren’t just a spectacle – they help astronomers understand these interstellar processes. Here, for example, different gases emit light different wavelengths of light, which are color coded: blue for doubly ionized oxygen and red for ionized hydrogen and ionized nitrogen.
The green gases have not been disturbed by shock waves as recently as the blue ones, so they have had time to cool and diffuse into their more airy chaotic shapes.
Since the nebula is still expanding, studying these filaments and their compositions can help us better understand the structure of the cloud and how the supernova’s shock wave interacts with it. Such images taken at different times can also be compared to see how fast the shock wave is moving.
Hubble’s 2015 observations were compared with images of the nebula taken in 1997 – see the video above – and scientists were able to calculate that it is expanding at a speed of 1.5 million kilometers (932,000 miles) per hour. The diameter of the Earth, for reference, is 12,742 kilometers.
Ultimately, the remains of the young, hot star that died in such a dramatic fashion will all be blown away, scattered in the interstellar medium. Even for stars, all things must come to an end.
You can download a wallpaper-sized version of the reprocessed image from ESA’s Hubble website.