NASA's James Webb Telescope (JWST) has made a remarkable discovery in a galaxy located three billion light years away from Earth. The $10 billion telescope detected a brilliant light, believed to be its first observation of a dying star exploding, also known as a supernova.

When a star exhausts its fuel, it undergoes a dramatic event known as a supernova, marking its final stage. As the pressure drops, the star expands to at least five times the mass of our sun, equivalent to about 333,000 Earths, before detonating and releasing vast amounts of debris and particles.

The supernova occurred in the galaxy SDSS.J141930.11+5251593, and JWST captured images that revealed a gradual dimming of the object's light over a span of five days, providing a crucial clue pointing towards a supernova.

What makes this discovery even more intriguing is the fact that JWST was not specifically designed to detect dying stars. Mike Engesser of the Space Telescope Science Institute (STScI) stated to Inverse, the first outlet to report on this finding, that not only did James Webb spot a supernova, but astronomers are puzzled by this discovery precisely because the telescope was not intended for such observations.

The potential supernova was captured using the NIRCam instrument on board JWST, which is primarily designed to detect light from the earliest stars and galaxies through a broad range of infrared light. The instrument is equipped with coronagraphs, allowing astronomers to take pictures of faint objects surrounding a bright central object, such as stellar systems or, in this case, stellar explosions.

Engesser revealed that JWST stumbled upon the supernova while investigating the distant galaxy, attributing the discovery to serendipity.

Interestingly, the dying star, appearing as a small bright dot in the images, was absent in pictures of the galaxy taken by the Hubble Space Telescope in 2011. Engesser and his team utilized software designed to identify differences in the photographs, leading them to the bright speck that turned out to be the supernova.

Just one week after its launch, JWST has already proven its worth. Not only did it provide its inaugural deep-space images on July 12, but scientists have now announced the telescope's detection of a 13.5 billion-year-old galaxy, making it the oldest observed by human eyes in the entire universe.

Named GLASS-z13 (GN-z13), this galaxy formed a mere 300 million years after the Big Bang, which occurred approximately 13.8 billion years ago. The previous record-holder, GN-z11, was discovered by the Hubble Telescope in 2015 and dated back to 400 million years after the birth of the universe.

JWST captured a glimpse of GN-z13 using its Near Infrared Camera (NIRCam) instrument, renowned for its ability to detect light emitted by the earliest stars and galaxies.

The top image accompanying this article depicts the binary stars of Eta Carinæ and the remnants of ancient eruptions forming the Homunculus Nebula around the star, as seen in an image captured by the Hubble Space Telescope.