Stunning Image Shows Star Exploding in Powerful Death by Supernova

Astronomers have caught a massive star, located around 500 million light-years from Earth, erupting in a cosmic explosion marking the end of its life.

The Cartwheel galaxy, in which the astronomers witnessed the explosion, is pretty remarkable in itself as it was once a standard spiral galaxy like the Milky Way until a head-on collision with a smaller companion galaxy.

The cosmic collision which occurred several million years ago warped the shape of this galaxy and gave it its distinctive cartwheel-like appearance. A recent image of the Cartwheel galaxy shows something special occurring in the distant region of space.

Placed side-by-side with an earlier image taken with a different instrument here on Earth, the new image creates an impressive "before and after" comparison that shows a star exploding.

Cosmic Spot the Difference

The cartwheel galaxy
(Left) An image of the Cartwheel; galaxy captured by the Multi Unit Spectroscopic Explorer (MUSE) mounted on ESO’s Very Large Telescope (VLT). (Right) the same galaxy imaged by the New Technology Telescope. In the left hand corner of the image on the right image astronomers have caught the final moments of a massive star as it goes supernova. ESO

In the picture above, the image on the left shows the Cartwheel galaxy before the supernova event, which has been designated SN2021afdx. This image was captured by the Multi Unit Spectroscopic Explorer (MUSE) mounted on ESO's Very Large Telescope (VLT) in August 2014.

The image on the right was captured in December 2021 by the New Technology Telescope (NTT), a 3.58-meter telescope developed in 1989 that was the first telescope in the world to have a computer-controlled main mirror.

In the bottom left-hand corner of the NTT image, there is a bright white dot that represents a massive star going supernova, something that is absent in the MUSE image of the same galaxy.

The death throes of the star resulted in what scientists call a type II supernova, an explosion that marks the endpoint of stellar evolution. Unlike type Ia supernova, in which little is left behind of the exploding star, type II supernovas can leave behind material around a stellar remnant like a neutron star or a black hole.

Supernovas can be so powerful that the light they emit can outshine the entire galaxy in which they sit and remain visible to observers for months or even years.

They also play an important role in cosmic evolution as they spread the heavy elements that are forged in the massive stars throughout their host galaxies and beyond.

When scientists say that we are made of starstuff, this is quite literal and possible thanks to supernovas like SN2021afdx. The heavy elements spread during the death throes of these stars will also go on to become the building blocks of the next generation of stars, as well as the planets that surround them.

The supernova SN2021afdx was first spotted in November 2021 by the ATLAS survey, a system of four telescopes in Hawai'i, Chile, and South Africa with the primary mission of spotting asteroids on a collision course with Earth.

This discovery was then followed up by the ePESSTO+ survey operated by the European Southern Observatory, which focuses on the observation of transient objects or events, things that may only be visible for a short period of time.