What picture did NASA take of a supernova? Rare space event captured by Hubble Telescope - phenomena explained

Despite the launch of the James Webb Space Telescope, Hubble continues to capture stunning images from the cosmos

NASA’s Hubble space telescope has captured amazing images of a supernova - one of the most elusive space events.

It comes just months after Hubble’s successor - the James Webb Space Telescope - came online after being launched on Christmas Day 2021. The newer deep space device has already captured some of the most stunning images of the cosmos humanity has ever seen.

But Hubble continues to work from its orbit high above the earth. It has been there since 1990 and has provided us with an insight into the early universe.

So, what does its latest image show us - and what is a supernova? Here’s everything you need to know.

The Hubble telescope sits in low-earth orbit (image: Getty Images)

What is the Hubble telescope?

The Hubble Space Telescope is a NASA spacecraft that has sat in low-Earth orbit for 32 years. When it was launched, it was the first telescope to sit in space, which allows it to see more than terrestrial telescopes because it has next-to-no interference from clouds or human communications.

While Hubble can take images in visible light, it tends to rely on its ultraviolet and infrared capabilities which allow it to peer into galaxies cloaked in dust to pick out distant objects. The instruments on the James Webb telescope are even better at doing this work.

The telescope uses an effect known as gravitational lensing to look deeper into the cosmos. This occurs when gravity is distorted by large concentrations of matter, like galaxy clusters, which bend light so you can see further into space.

In its simplest form, the distortion acts as a magnifying glass and allows Hubble to see much older objects in the distant universe.

The Hubble space telescope has captured an image showing three stages of a supernova (image: NASA)

What does the Hubble telescope’s new image show?

Hubble’s latest remarkable image shows the explosion of a star in the early universe. The star in question destroyed itself 11 billion years ago - the universe is 13.8 billion years old.

As well as the star’s age, what is especially remarkable about the Hubble image is that it captures the exploding star over three different phases. It initially appears to be blue (i.e. very hot) before cooling down to become red over a period of around eight days.

All three images hit the telescope at the same time because the light followed different paths to reach its instruments.

"You see different colours in the three different images," said Patrick Kelly, who led the study into the images and is also an assistant professor in the University of Minnesota’s School of Physics and Astronomy.

"You’ve got the massive star, the core collapses, it produces a shock, it heats up, and then you’re seeing it cool over a week. I think that’s probably one of the most amazing things I’ve ever seen!"

What is a supernova?

A supernova is basically an exploding star. These explosions are extremely powerful and can be very bright - indeed, they can outshine their entire galaxy when they go off and have been witnessed in the skies above the earth during daylight hours in the past.

This type of event occurs when a star that’s at least five-times the size of our sun collapses in on itself because it has started to run out of the nuclear fuel burning in its core. The shockwaves generated by this sudden collapse trigger an explosion in the outer parts of the star.

What this sudden flash leaves behind is a cloud of hot gas - a nebula - and a very dense core. Stars that are around 10-times the size of our own sun will leave behind an even denser object - a black hole.

These events are not usually witnessed because they happen so quickly. Despite there being billions of stars in the observable universe, scientists only pick up a few hundred per year outside of our galaxy.

Astronomers estimate that two to three supernovas occur each century in galaxies like our own Milky Way, but we tend to miss them because they are hidden behind space dust.