They observe for the first time the birth of a supernova
An international team led by the Dunlap Institute of the University of Toronto (Canada) has observed for the first time a type Ia supernova from the very moment of its birthin a study in which the researcher from the Institute of Space Sciences (ICE-CSIC) Lluís Galbany has participated.
The research, published today in the journal "Nature Astronomy", has been carried out using the KMTnet (Korea Microlensing Telescope Network) network of telescopes in Chile, South Africa and Australia.
As explained by Lluís Galbany, who is also a member of the Institute for Space Studies of Catalonia (IEEC), supernovae (SN) are the result of stellar explosions and type Ia are thermonuclear explosions of white dwarf stars in binary systems, and make up the most common observed variety.
"Are from vital importance to understand the origin of metals and the accelerated expansion of universe", The researcher has highlighted, who has recalled that, despite its importance, there are still pending questions about its origins, since the mechanisms of explosion of Ia supernovae continue to be the subject of scientific debate.
Scientists Yuan Qi Ni, Dae-Sik Moon, and Maria R. Drout of the University of Toronto's Dunlap Institute have led this international program for the earliest detection of supernovae and comprehensive follow-up observations.
According to the researchers, this supernova, named SN 2018aoz, it exploded on March 29, 2018 and they could detect it from an hour from the first light of its explosionwhich is the earliest multiband localization of a type Ia supernova to date.
In addition, they have obtained crucial natal information from how the explosion took place
"Type Ia supernovae take about 16-19 days from when they explode to reach maximum brightness. If we had instrumentation looking at the whole sky all the time we would discover SN in its first moments, but until about four or five years ago this was not possible ", Galbany has pointed out.
New projects like ASAS-SN, ZTF or ATLAS use relatively small telescopes to scan the entire sky more often and can find objects that were not there before with an advance that previously was impossible.
"Before, it was a milestone to discover an SN seven or nine days after the explosion, and now quite a few can be discovered within one to three days after the explosion," Galbany pointed out.
In this case, it is even earlier, since the SN was detected from one hour from the first light of its explosion.
The ICE-CSIC has contributed with the infrared observations made from the Cerro Tololo observatory in Chile (SMARTS telescope, ANDICAM instrument).
"SN 2018aoz is part of a set of Type Ia supernovae that we were observing in the infrared to measure distances to their galaxies so we could determine the rate of expansion of the local Universe"has detailed the Catalan researcher.
Galbany has reported that the data obtained so far reveal a concentration of metals of El Hierro family in the outermost 1% of the material ejected by the supernova.
This reveals a rapid reddening of supernova lightthat is, a temporary absorption of its bluer light, during the first twelve hours of its infancy.
This finding indicates that normal Type Ia supernova explosions could be started by burning material on the surface or else undergo an extreme mixing process that causes heavier elements from the interior to bloom to the surface.
In addition, according to the researchers, these very early data allow us to distinguish between different explosion models of Ia supernovae.
