Space researchers can already predict a stellar explosion billions of light years away. The decisive factor is the gravitational force.
Munich - A supernova is a massive stellar explosion that can endanger even distant planets. Such a supernova with the dark name “Requiem” will be seen on Earth in about 13 years. However, the distant event poses no danger to our home planet. But how did space research become aware of a cosmic spectacle that will only be observable around 2037?
Supernova ten billion light years away will appear again in 2037
The “Reqiuem” stellar explosion took place in the background of the galaxy cluster MACS J0138, about ten billion light-years from Earth. This is why it takes so long for the light from the supernova to reach our solar system. But astronomers knew about the existence of the supernova before its light was captured by telescopes. The supernova was announced by NASA in 2021.
The reason researchers can predict the arrival of the stellar explosion in 2037 is simple: They discovered “Requiem” in the Hubble Space Telescope’s archival data back in 2019 – three times. Although it won't be visible to the naked eye, the space agency hopes to be able to witness it with telescopes given the supernova's predicted appearance in about 13 years.
Light from the supernova “Requiem” travels for different lengths of time due to the gravitational lensing effect
Three tiny dots were visible in the space telescope images from 2016. However, these points all represent the same event, the supernova “Requiem”. To be precise, they are witnessing the aftermath of the explosion. The spots vary in brightness and color, which NASA researchers say is due to the different phases of the supernova. In 2019, three years later, the dots in images of the same section had disappeared.
The reason why multiple images of different stages of the same stellar explosion can be seen is due to something called gravitational lensing. More than halfway through, the light from the supernova hits the giant galaxy cluster MACS J0138. According to the general theory of relativity, its gravitational force not only leads to the curvature of space, but also to the fact that light rays have to make an arc. Each of the points of light visible in the Hubble images took a different path past or through the galaxy cluster.
“Whenever light passes near a very massive object, the distortion of spacetime [...] delays the travel of light around that mass,” explained Steve Rodney from the University of South Carolina back in 2021. Researchers have the path of light through the galaxy cluster and vast amounts of dark matter simulated with the help of computer models. Because the light in the image predicted for 2037 is likely to have moved through the center of the cluster, it lags the other images by more than 20 years.
“Very, very large telescope” would reveal a view of an unexploded predecessor star
Rodney roughly illustrates the path of the light rays with the departure of several trains from the same station, traveling on different routes and arriving at the same destination at different times. The images from 2016 show well-traveled light, captured by the Hubble Space Telescope within half a year, arranged in an arc around the galaxy cluster.
In a few years, astronomy will be waiting with bated breath for the return of “Requiem” and it will become clear how accurate the researchers were with their prediction. In their specialist article on the matter published in 2021, the researchers estimate a possible deviation of two years. But more important than the actual timing of the supernova's reappearance are the implications of the phenomenon.
“If you were to point a very, very large telescope at this region today, you would see the supernova’s predecessor star, which has not yet exploded,” the
Neue Zürcher Zeitung
quotes co-author Gabriel Brammer from the Niels Bohr Institute in Copenhagen. In addition, the long wait for the fourth image of the supernova could help researchers increase the accuracy of calculating the expansion rate of the universe.
Stars don't necessarily have to come to an end in a giant supernova. Researchers have accidentally discovered a new way stars in the universe can die.
The editor wrote this article and then used an AI language model for optimization at his own discretion. All information has been carefully checked.
Find out more about our AI principles here.