James Webb space telescope finds heaps of supernovae in the early universe
Star explosions are particularly valuable for research and are intensively sought after. The James Webb space telescope turns out to be an enormous help.
Dozens of supernovae in one section of the sky
(Image: NASA, ESA, CSA, STScI, JADES Collaboration)
The James Webb Space Telescope (JWST) is a true "supernova discovery machine" and has increased the number of known stellar explosions in the early universe tenfold. This has now been made public by a research team led by astronomer Christa DeCoursey from the University of Arizona. The group compared images that the ultra-modern instrument took of an extremely small section of the sky within a year. In the area the size of a grain of rice, which is held in front of the eye with an outstretched arm, they discovered around 80 supernovae in this period. This includes by far the earliest supernova that we know of. The star in question exploded when the universe was just 1.8 billion years old.
A glimpse into the early youth of the cosmos
(Image: NASA, ESA, CSA, STScI, Christa DeCoursey (University of Arizona), JADES Collaboration)
As the research team explains, before the space telescope was launched, only a handful of supernovae were known to have exploded when the universe was less than 3.3 billion years old. The section of the sky now analyzed, on the other hand, even contains many supernovae from the time when a maximum of two billion years have passed since the Big Bang. So far, it has only been possible to study stellar explosions that took place in the "late youth" of the cosmos at the earliest. Now it is possible to study those in the "early youth" and "late childhood". There is hope of being able to focus on the "baby" and "crawling" phase at some point.
Once the extremely early supernovae have been identified, the next step will be to determine whether they are fundamentally different from those we know from the later universe. Another focus is on the so-called type Ia supernovae. These have long been regarded as so-called standard candles. This means that their distance could be determined precisely enough to measure distances in the universe as a whole. The data from the JWST will now be used to test whether this is still true for such large distances, because only then could the expansion speed of the cosmos be reliably determined. An initial analysis has now cast doubt on this, but further research is still needed.
The research has now been presented at a meeting of the American Astronomical Society (AAS) in the US state of Wisconsin. It once again underlines the immense potential associated with the space telescope. The device opens a new window on variable celestial bodies and every time this has happened in the past, "extremely exciting things" have come out of it, says an expert from the Space Telescope Science Institute. However, only the extremely large number of supernovae discovered and their distances are still the most interesting aspects.
(mho)