NASA is observing a supernova remnant, named SNR 0519-69.0, in order to determine the timing of the stellar explosion.
While astronomers have seen the debris from dozens of stars that have exploded in our galaxy and nearby galaxies, it is often difficult to determine the timing of the star's death. By studying the spectacular remnants of a supernova in a nearby galaxy and using telescopes of NASA, a team of astronomers has found several clues that will help turn back the clock.
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The supernova remnant called SNR 0519-69.0 (SNR 0519 for short) is the debris from an explosion of a white dwarf. After reaching a critical mass, either by pulling matter from another star or by merging itself with another white dwarf, the star suffered thermonuclear explosion and destroyed. Scientists use this type of supernova, called Type Ia, for a wide range of scientific studies ranging from studies of thermonuclear explosions to measuring distances in galaxies in billions of light years.
SNR 0519 is located at Large Magellanic Clouda small galaxy 160,000 light years from Earth. This composite image shows X-ray data from the Chandra X-ray Observatory NASA and optical data from the Hubble Space Telescope. X-rays from SNR 0519 with low, medium and high energy appear in green, blue and purple respectively, with some of these colours overlapping to appear white. The optical data show the perimeter of the remnant in red and the stars around the remnant in white.
Astronomers combined data from Chandra and Hubble with data from the retired space telescope Spitzer NASA to determine how long ago the star SNR 0519 exploded and to learn about the environment in which the supernova appeared. These data provide scientists with the opportunity to "rewind" the tape of stellar evolution that has occurred since then and understand when it began.
The researchers compared Hubble images from 2010, 2011 and 2020 to measure the velocities of SNR 0519 material in the explosion wave, which range from approximately 3.8 million to 5.5 million miles (9 million kilometres) per hour. If the speed was towards the upper end of these estimated speeds, astronomers determined that the light from the explosion would have reached Earth about 670 years ago, or during the Hundred Years' War between England and France and the heyday of the Ming dynasty in China.
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However, it is possible that the material has slowed down since the original explosion and that the explosion occurred less than 670 years ago. Chandra and Spitzer data provide evidence that this is what is happening. The astronomers they found that the brightest regions in the X-ray emission of SNR 0519 are where the slowest moving material is located and no X-ray emission is associated with the fastest moving material.
These results suggest that part of the blast wave has impinged on dense gas around the remnant, causing it to slow down as it travelled. Astronomers can use additional Hubble observations to determine more accurately when the time of the collapse of the star SNR 0519 should actually be determined.
A paper describing these results was published in the August issue of The Astrophysical Journal and a preprint is available online.
Source: phys.org
