In 2016 astronomers detected three new points of light in space. They corresponded to a supernova, a gigantic explosion in space that occurred ten billion years ago. Being an explosion, it went out a few years later, in 2019. But nothing happens, we will see the same explosion again in a few years.
A group of astronomers discovered the supernova thanks to the Hubble Space Telescope. By analyzing the infrared data, the team realized that there were a total of three light sources coming from the same explosion. Something made the light drift at the start and it is what caused it to appear from three different points for us.
Like any supernova explosion, it is huge but it is not forever. While they are not as short as an artifact explosion on Earth, they generally only last a few years. Relatively little for the age of the Universe. In this case it has been a total of three years, in 2019 the three points of light faded and turned off coming from the supernova.
A route of 20 extra years
Located in the MRG-M0138 galaxy, the supernova is about ten billion light years away. As such, the explosion has taken some ten billion years to reach us. We are looking at the past. But things get a little more complicated It turns out that not all the explosion has reached us yet.
Researchers believe that a fourth point of light will appear in about 16 years (year up, year down …). This is due to a principle called gravitational lensing. The idea behind this is that light, while traveling in a straight line, can bend around an object massive enough to alter the path of photons.
This is what these researchers believe has happened to this supernova. There are indications of a fourth point of light coming from the supernova, but this fourth light source has taken a different route that will cost you an extra 20 years of travel on its route of approximately 10 billion years. What’s more, we can see the white dwarf before it explodes, even though we’ve already seen the explosion once.
Specifically, they believe that the light from this supernova se scattered in different points of light due to the galaxy cluster MACS J0138. This caused it to take different trajectories and hence we see several points now. Of course, it has not yet fully arrived. In the following animation you can see this concept better:
In addition to curiosity itself, this allows astronomers to better understand the Universe and measure distances more accurately. From different values such as the time it takes for the light to arrive or the distance between the different points, it is possible to obtain better figures about the distance to the supernova and what is in between.
Via | University of Copenhagen