A dying star’s final gasps of light have been captured in a collection of hauntingly stunning photos that are slowly resonating throughout space.
The supernova explosion of a big star in 2016 was photographed in stunning detail by the Hubble Space Telescope as the glow expanded outward over a period of more than five years.
A wealth of knowledge about the lifecycle of dead stars and the material around the explosion in its home galaxy of Centaurus A can be found in the movie made from the photos that were pieced together.
According to astronomer Stephen Lawrence of Hofstra University in the US, “a good daily example is to envision the culmination of a fireworks show — the intense burst of light from a shell at the end of the performance will light up the smoke from previous shells that is still lingering in the region.”
How many shells had previously exploded, how opaque the smoke from a particular shell is, how fast and in what direction the wind was blowing—all of these things can be measured by comparing a series of photographs taken over several minutes and not just the most recent explosion that is lighting up the scene.
The Light Echoes
A wonderfully beautiful phenomena, light echoes are best observed from a distance. They happen when anything sends off a flash of light towards space.
The light will reflect and arrive at a later time than the initial burst if it runs against a physical obstacle, such as clouds of cosmic dust.
Similar to a sound echo, except with light instead of sound. These light echoes can be used to map and comprehend space and the objects that exist in it.
The Centaurus A
Since Centaurus A, the host galaxy of the 2016 supernova, is more than 12 million light-years away, astronomers have regularly visited it to see if they can track changes over time. That tenacity paid off. They were not only able to gather information on the supernova, known as SN 2016adj, but also to record its light echoes.
Astronomer Lluis Galbany of the Institute of Space Sciences in Spain claims that the blast wave from this intense supernova explosion is speeding away from Earth at over 10,000 kilometers per second (more than 6,200 miles per second).
Related: Will the Supernova in 2022 affect Earth?
The Intersting Supernovae
Supernovae are interesting because these cosmic explosions produce many of the heavy elements, such as carbon, oxygen, and iron, which make up our galaxy, stars, and planet. This intense flash of light that the supernova emits ahead of the blastwave is what is causing the expanding rings we can see in the images.
It’s kind of strange, Centaurus A. It is categorized as an elliptical galaxy, which are typically smooth, oval-shaped galaxies with little to no dust and ancient stars.
However, Centaurus A is somewhat twisted, highly dusty, and bursting with star formation. These are all indications of a cosmically recent collision with a different galaxy, whose consequences have not yet subsided.
How Did The Light Encounter Several Dust Clouds?
The light from the supernova is believed to have encountered several dust clouds as it approached Earth. We would experience this as a series of rings getting bigger from where we are standing. During the five-year monitoring period, four unique light echoes were seen, indicating that there were four distinct dust clouds that were each large and dense enough to produce a light echo.
The astronomer Maximilian Stritzinger of Aarhus University in Denmark and his team were able to map the dust surrounding the supernova using these light echoes. According to their findings, the arid buildings are filled with material that isn’t dense enough to produce a discernible light echo.
The study reveals that there are some observations for which Hubble is still king, notwithstanding our excitement for the JWST image of Centaurus A, which will cut through the dust to reveal the mysterious galaxy’s heart.
Since Hubble has been in orbit for several years, it has been able to record an observation that spans several years and gives comprehensive information about the structure of an additional galaxy.
“The data set is amazing, and it allowed for the creation of stunning colorful visuals and animations showing the development of the light echoes over a five-year period,” according to Stritzinger. It is an uncommon occurrence that has only been recorded in a small number of other supernovae.