This image shows the orange and pink clouds that make up the Vela supernova remnant. Credit: ESO/VPHAS+ team. Acknowledgement: Cambridge Astronomical Survey Unit
Just 11,000 years ago – only a moment in the huge scheme of the Universe – a massive star exploded in spectacular fashion, with only tendrils of pink and orange gas left behind.
Those leftovers are called the Vela supernova remnant, and it’s recently been imaged in wonderful detail by OmegaCAM at the VLT Survey Telescope in Chile. The remnant is in the constellation of Vela – which is Latin for a ship’s sails.
The VLT Survey Telescope has a very large field of view, and this has allowed the researchers to take such a wide shot – the whole image is a mosaic, equivalent to nine full moons in the night sky.
As the supernova exploded, the outermost layers of the progenitor star were ejected into the surrounding gas, creating filaments. These explosions cause shock waves that move through the gas, compressing it and creating intricate thread-like structures. The energy that is released heats the gaseous tendrils, making them shine brightly.
What remains of the explosion is now a neutron star – an ultra-dense ball in which the protons and electrons are forced together into neutrons. The neutron star in the Vela remnant, unfortunately can’t be seen in this image, but it’s a pulsar, and is off the upper left corner.
In fact, astronomers from the University of Sydney in 1968 were able to show that the Vela supernova remnant was associated with the Vela pulsar, which provided direct observational evidence that neutron stars are created from supernova.
To create a stunning colour image like this, multiple filters of different wavelengths of light are layered on top of each other. In this case the wavelengths are 350 nanometres, shown in magenta (this equates to infrared), 440 nanometres for blue, 480 nanometres for green and 625 nanometres for red.
These images are usually thought of as the domain of space telescopes like Hubble and the James Webb Space Telescope, but ground based telescopes like VLT Survey Telescope can be much larger, allowing astronomers to look at larger sections of the night sky in one go.