Though a doomed star exploded some 20,000 years ago, its tattered remnants continue racing into space at breakneck speeds—and NASA’s Hubble Space Telescope has caught the action.
The nebula, called the Cygnus Loop, forms a bubble-like shape that is about 120 light-years in diameter. The distance to its center is approximately 2,600 light-years. The entire nebula has a width of six full moons as seen on the sky.
Astronomers used Hubble to zoom into a very small slice of the leading edge of this expanding supernova bubble, where the supernova blast wave plows into surrounding material in space. Hubble images taken from 2001 to 2020 clearly demonstrate how the remnant’s shock front has expanded over time, and they used the crisp images to clock its speed.
By analyzing the shock’s location, astronomers found that the shock hasn’t slowed down at all in the last 20 years, and is speeding into interstellar space at over half a million miles per hour—fast enough to travel from Earth to the moon in less than half an hour. While this seems incredibly fast, it’s actually on the slow end for the speed of a supernova shock wave. Researchers were able to assemble a “movie” from Hubble images for a close-up look at how the tattered star is slamming into interstellar space.
“Hubble is the only way that we can actually watch what’s happening at the edge of the bubble with such clarity,” said Ravi Sankrit, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland. “The Hubble images are spectacular when you look at them in detail. They’re telling us about the density differences encountered by the supernova shocks as they propagate through space, and the turbulence in the regions behind these shocks.”
Credit: NASA, ESA, STScI
2023-09-28 16:48:03
Original from phys.org
