Thursday, September 15, 2022

NASA Traces Supernova Remains Back to the Middle Ages

Monisha Ravisetti - 

In the 14th century, while bloodshed from the Hundred Years' war spilled onto Earth, remnants of a dead star might have shone in the sky.


Three very strong telescopes combined to bring you this image of a supernova's graveyard.
 NASA© Provided by CNET

NASA announced Monday that three powerful telescopes -- the Hubble, the Spitzer and the Chandra X-Ray Observatory -- joined forces to study debris stemming from a white dwarf's death. Think of these stellar remains as the overall aftermath of the star's final moments, the environment in which it met its demise.

The astronomers who parsed all this cosmic data say they've managed to glean enough clues to decode an exquisite timeline of the destroyed star's violent detonation long, long ago.

"This data provides scientists a chance to 'rewind' the movie of the stellar evolution that has played out since and figure out when it got started," Chandra team members wrote in a statement. A preprint of these results can be seen here.

Eventually, this could elucidate when and where the stellar body might have blown up in the first place, but as the team began piecing together that story, it also realized something immensely fascinating about one particular part of the supernova's remains.

An aspect of the star's mortal evidence, located some 160,000 light-years away from Earth in a small galaxy called the Large Magellanic Cloud, might have emitted luminescence post-explosion that finally reached our planet during the Middle Ages. Yes, that means it decked the night sky within the same year we attribute to the apotheosis of the Ming Dynasty and most tragic point of the Black Plague.

The remnant is named SNR 0519-69.0, or SNR 0519 for short. (SNR stands for supernova remnant, as you might have guessed.)



Here's a general idea of the thermonuclear explosion that led to the white dwarf star's Type 1a supernova, and eventual SNR. Chandra X-Ray Observatory© Provided by CNET

On the upper end of their estimate, the scientists believe the remnant's deep-space light might have appeared about 670 years ago. However, based on its space-borne trajectory, they say it's also likely "the material has slowed down since the initial explosion and that the explosion happened more recently than 670 years ago."

OK, but what am I looking at here?

In the striking image released alongside this discovery, SNR 0519 seems to be a translucent, magenta blob against the star-studded canvas of space.

What you're looking at is a conglomerate of the telescopes' observations, overlaid to create a full diagram of the stellar fragment. Let's break it down.


Whoever picked the color combination for this space pic is probably my hero. 
NASA© Provided by CNET

The strong, pinkish-red areas and white wispy trails come from Hubble optical data to indicate the SNR's outline. If you look closely, you'll also see some green splotches, blue marks and purple halo-like designs leaking from the two. Those are colorized X-Ray observations that represent, respectively, low, medium and high energies emitted. Some overlaps of Chandra observations also show up as white-ish areas, and the brightest regions of the image dictate the slowest-moving material.

If you're wondering about Spitzer, this machine was more of a behind-the-scenes helper. It provided lots of data integral to the timeline goal of the team's study.

Of note, Hubble images of SNR from 2010, 2011 and 2020, NASA says, also measured speeds of the material provoked by the explosion's blast wave. Put together, this led to the conclusion that the remnant spurted out within a whopping range of 3.8 million to 5.5 million miles per hour -- the higher end of that is the part that supports the team's 670 years estimation for the initial eruption.

But again, NASA urges that "these results imply that some of the blast wave has crashed into dense gas around the remnant, causing it to slow down as it traveled," deeming the other scenario to have a solid likelihood, too.

No comments:

Post a Comment