Supernovas play a crucial role in the chemical evolution of the universe by producing heavy elements such as iron and gold, which are essential building blocks for planets and life. They also serve as important cosmic distance markers, allowing astronomers to measure the expansion rate of the universe and study its history.
When certain extremely big stars reach the end of their lives, they explode, creating supernovae. The star releases material from its outer layers through a shock wave in this cataclysmic epilogue, revealing the numerous elements it was made of.
The research team created a lens-like model of the galaxy’s gravitational field and using that model, it was feasible to ascertain that the light from these three photos traveled down three distinct courses, each of which varied in the distance by a few days.
This explains the three colors shown in the photos, as the color of the light released changes as the supernova’s gas cools and expands. The light emitted tends to be more blue when the temperature is greater and red when the temperature is lower.
Hence, the green and red photographs correspond to 2 and 8 days, respectively, after the explosion, whereas the blue image represents a photo of the supernova taken a few hours after the stellar explosion.
It was a red super-giant star with a radius 500 times larger than the Sun that burst 11.5 billion years ago, long before the Earth was born, precisely during the time when our Galaxy is assumed to have originated. With this knowledge, the radius of the star that exploded may be calculated.
The gravitational field of a neighboring galaxy serves as a lens for the Hubble Space Telescope’s photographs of this supernova, allowing us to see considerably farther in space and time than any of the nearby galaxies’ local supernovae.
The study of the supernova explosions of these red super-giant stars is consistent with our current understanding of how the heavier atomic elements were formed both inside stars and during supernova explosions: the next generation of gas and material from which solar systems and life as we know it are produced is made up of elements forged inside stars and released during these supernova explosions.
The gas in the galaxies of today would only include the hydrogen and helium created at the Big Bang and would not be able to support complex life, which needs additional heavier chemical components.
Additionally, the fact that this explosion was seen through a gravitational lens shows that an event occurring in the far reaches of the Universe may be seen several times means that, in theory, we could focus our equipment in advance to gain a close-up look of a star exploding into a supernova.
