The James Webb Space Telescope has detected large deposits of hot dust in two Type II supernovae that exploded in spiral galaxy NGC 6946. N+1 reported this by citing a study published in the journal. Monthly Notices of the Royal Astronomical Society (MNRAS).
In many distant galaxies, the nature of dust sources remains unexplored. In particular, these may be IIP-type supernova explosions caused by the gravitational collapse of the cores of massive stars. However, no direct observations have been made of the large reservoirs of hot and cold dust formed during supernova explosions in distant galaxies. Dust has only been observed in a few nearby Type II supernovae.
A team of astronomers led by Melissa Shahbandeh of Johns Hopkins University announced that they have discovered massive dust clouds in spiral NGC 6946, located at a distance of about 22 million light-years, from the explosions of IIP-type supernovas SN 2004et and SN 2017eaw. years from the sun.. Observations were made in the mid-infrared range using the MIRI instrument of the James Webb space telescope, 18 and 5 years after the eruptions themselves were detected.
The hot dust clouds detected in SNe 2004et and 2017eaw have masses greater than 0.014×10−4 and 4×10−4 solar masses, respectively. In the case of SN 2004et, these are the second largest dust deposits observed in the infrared of all extragalactic supernovae. The observed dust is heated by radiation produced as a result of a shock wave from a star’s expanding matter.
According to the scientists, if we accept that some of the dust particles may be in very cold or hidden opaque environments, the dust reserves may be even greater. Thus, up to 10,000 days after the explosion, multiple solar masses in the form of dust can be detected in extragalactic type II supernovae, which could point to the origin of dust in the early Universe, experts believe.
Formerly James Webb photographed Spiral galaxy located about 120 million light-years from Earth.