It is one of the greatest spectacles of the cosmos, but no one had captured it until now in its brilliant initial moments, and the honor – or luck – has fallen on a locksmith from the Argentine town of Rosario, an astronomy fan. It happened exactly on September 20, 2016 , when 58-year-old Victor Buso was testing a new camera on his 16-inch telescope. It pointed to the spiral galaxy NGC 613, located about 80 million light years from Earth, in the constellation Sculptor. As he later recounted, he had been observing that conglomeration of stars for eight days , because he suspected that something strange was happening there: he was not able to distinguish well inside.
So it was that Buso took a series of quick photographs to counteract the light pollution and… bingo! There was the supernova (that is, the outbreak of a massive star) SN 2016gkg , at the end of an arm of the galaxy.
Generally, supernovae, hidden by interstellar dust, are already difficult to observe, but it is also that the Argentine amateur astronomer had captured one of the rare images of what experts call “outbreak”, the violent outbreak that radiates from inside the dying star . By heating its surface, this supersonic wave triggers a brief flash, which this time lasted 25 minutes.
Cosmic lottery
Buso knew that this was not normal and sounded the alarm to the astronomical community . Subsequent observations with more powerful telescopes confirmed the origin of that “lightning bolt”. As Alex Filippenko, from the University of Berkeley, one of the people in charge of the study published by Nature – where the Argentine locksmith is also listed as the author – has highlighted, the inaugural outbreaks of supernovae give information about the star that is generally impossible to obtain from another way. “The Buso data is exceptional. It’s like winning the cosmic lottery! This is an extraordinary example of collaboration between professional and amateur astronomers ”, Filippenko celebrated.
Melina Bersten, also from Argentina, who has participated in the Nature study and works at the La Plata Institute of Astrophysics, estimates that the probability of observing this phenomenon is one in 10 million or even 100 million. The cosmic lottery perhaps falls short .
According to experts’ calculations, the initial mass of the star that ended its days as a supernova SN 2016gkg would be about twenty times our Sun. They also believe that it lost a large part of this mass, perhaps absorbed by a neighboring star, and exploded when it was approximately five times that of the king star. The most likely fate of the star’s center is to become a black hole, collapsed by its gravity.
Photo: C. Kilpatrick / University of California at Santa Cruz / Carnegie Institute for Science at Las Campanas Observatory, Chile.
Fuente: “A surge of light at the birth of a supernova”.
Nature volume 554, pages 497–499 doi: 10.1038 / nature25151
