A team of astronomers has captured the first-ever visual evidence of a star undergoing a “double detonation” explosion, shedding new light on a major cosmological mystery. The discovery was made by studying two concentric rings of calcium surrounding SNR 0509-67.5, a remnant of a type Ia supernova that occurred centuries ago.
The researchers found that the white dwarf at the center of the star exploded in two separate events, one smaller and one larger, with a shockwave shell pattern indicating that it occurred before reaching its critical mass limit. This discovery has significant implications for our understanding of the universe, particularly in measuring the expansion rate of the cosmos using type Ia supernovas.
Type Ia supernovas are considered “standard candles” because they always explode with the same brightness, allowing astronomers to measure distant distances and calculate the Hubble constant. However, recent years have seen contesting measurements of this constant, sparking a crisis in cosmology. The double detonation discovery may help resolve this puzzle.
The researchers used the European Southern Observatory’s Very Large Telescope and Multi Unit Spectroscopic Explorer instrument to capture the image of the two concentric rings of calcium surrounding the supernova remnants. This is the first direct visual evidence of the “double-detonation” mechanism, which challenges our current understanding of how white dwarfs explode.
The discovery has been hailed as a significant breakthrough in astronomy, offering new insights into the inner workings of cosmic explosions and shedding light on a major cosmological mystery.
Source: https://www.livescience.com/space/first-ever-evidence-of-star-double-detonation-captured-in-stunning-image