Low-Frequency Radio Observations Reveal Past Life of Supernova 1987A
An international team of researchers was able to peer in the past life of the brightest supernova remnant seen from Earth using low-frequency radio observations.
"Low-frequency radio waves are very sensitive to the presence of intervening plasma, so tell us a great deal about the density of matter immediately in front of the supernova remnant.," explained Professor Lister Staveley-Smith, Deputy Director of CAASTRO and ICRAR and co-author of the study, in a press release. "Their presence also tells us about the in-situ acceleration of very high-energy particles called cosmic rays, many of which are believed to be created in young remnants such as this."
Previous studies were able to observe about 0.1 percent of the star's life or 20,000 years before it exploded in 1987. However, a new study published in the journal Monthly Notices of the Royal Astronomical Society was able to probe million of years back to the life of the supernova remnant 1987A when the star is still in its long-lasting red supergiant phase.
"Just like excavating and studying ancient ruins that teach us about the life of a past civilisation, my colleagues and I have used low-frequency radio observations as a window into the star's life," explained Joseph Callingham, a PhD candidate with the University of Sydney and the ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO) and lead author of the study, in a statement.
For their observation, the researchers used the Murchison Radio-astronomy Observatory because it is considered to be one of the most radio quiet places in the planet. They then discovered that the red supergiant phase of the star lost its matter at a much slower rate and generated slower winds that pushed into its surrounding environment than what was previously thought.
With their new observation regarding the past life of Supernova 1987A, researchers can now go back to their simulations and tweak it a little to better construct the physics of the supernova.