Sat,2 September 2023
In a celestial spectacle reminiscent of a pearl necklace, the James Webb Space Telescope (JWST) has captured a mesmerizing image of SN1987A, a renowned supernova, offering an unprecedented glimpse into the heart of this cosmic explosion.
SN1987A, as it is commonly known, holds a special place in astronomical history. In 1987, when this star met its explosive demise, it became the closest and brightest supernova visible from Earth in nearly four centuries. Now, the $10 billion (£8 billion) Webb observatory has provided a never-before-seen perspective on this celestial phenomenon.
Situated a mere 170,000 light-years away in the Large Magellanic Cloud, a dwarf galaxy adjacent to our Milky Way, SN1987A has captured the fascination of astronomers for its ability to unravel the mysteries of massive stars at the end of their lifecycles.
The striking image captured by the Webb telescope reveals a series of luminous rings, representing layers of gas and dust expelled by the dying star during its various phases of decay. These rings have been illuminated by the shockwaves generated during the star's final moments before its cataclysmic collapse and explosion.
One of these rings resembles a string of pearls, comprising material ejected approximately 20,000 years before the star's ultimate demise. Webb's exceptional sensitivity and resolution have enabled scientists to observe new hotspots emerging beyond the previously illuminated ring.
Dr. Roger Wesson from Cardiff University, UK, explained, "In addition, we see emission from molecular hydrogen in the ring that was not necessarily expected and something only JWST could have revealed with its superior sensitivity and resolution."
A new revelation in the image is the crescents or arcs of emission within the pearl necklace, just outside the dense central region, resembling a keyhole. The origins of these crescents remain a mystery, with Dr. Mikako Matsuura, the lead scientist behind the analysis, speculating that they may be illuminated by a reverse shock, suggesting a shockwave moving back toward the keyhole.
Despite these remarkable observations, Webb cannot peer into the dense dust field that conceals the remnant of the exploded star, a compact object composed entirely of neutron particles measuring only a few tens of kilometers across.
For over three decades, astronomers have studied SN1987A to understand why this particular star underwent a supernova explosion. It is believed that the star was relatively young and hot, possibly 20 to 30 times more massive than our Sun, challenging existing theories about the types of stars that can explode in this manner.
Dr. Wesson emphasized, "The indications are that Webb will be operational much longer than originally envisaged - maybe 20 years - and that will give us a very powerful tool to keep on monitoring SN1987A to see how it is changing."
The captivating image released by Webb is just one of its many feats. Equipped with a suite of spectrometers, the telescope can analyze light to reveal the chemistry, temperature, density, and velocity of celestial objects.
As Webb's Near Infrared Spectrometer, or NIRSpec, continues to study SN1987A, the scientific community eagerly awaits the forthcoming report, expected to unveil even more astonishing revelations about this remarkable supernova.
The James Webb Space Telescope, a collaborative project of the US, European, and Canadian space agencies, was launched in December 2021 and is hailed as the successor to the Hubble Space Telescope.