The Cartwheel galaxy is slightly larger than the Milky Way; it has a radius of 65,000 light-years (or an estimated diameter of 150,000 light-years) and has been the scene of the birth of a new supernova. Supernovae are the brilliant stellar explosions that occur when massive stars reach the end of their lives; the explosion may be visible to observers for months or even years. And it is that, when a supernova occurs, it produces a bright outburst that can outshine the entire host galaxy.
A very recent supernova
Named SN2021afdx , this new supernova is located in the lower left of the unusual Cartwheel galaxy located about 500 million light-years distant from Earth in the Sculptor constellation.
Astronomers from the European Southern Observatory (ESO) managed to capture this cosmic moment in December 2021 using the New Technology Telescope (NTT) of the European Southern Observatory in Chile. NTT is a 3.58-meter near-infrared and optical telescope that is equipped with the world’s first computer-controlled primary mirror – with active optics that enable the telescope to maintain optimal image quality while remaining flexible. to be adjusted during observations – and is located at the La Silla Observatory in the Atacama Desert in Chile. The other image of this composition is the comparison with the same galaxy, but taken with the Very Large Telescope (VLT) in August 2014, before the stellar explosion occurred.
The birth of the supernova, which has been officially classified as a type II (classical explosion or core collapse supernova due to implosion), can be seen in the lower left of the most recent image (the one on the right).
” Supernovae are one reason astronomers say we’re all made of stardust: They spray surrounding space with heavy elements forged by the parent star, which can end up as part of later generations of stars.” , the planets that surround them and the life that may exist on those planets,” the ESO astronomers explained in a statement.
Scientists relied on several observations from other telescopes around the globe to confirm the stellar explosion in the Cartwheel galaxy, such as the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) located in Hawaii, the Advanced Public Spectroscopic Survey of ESO for transient objects (ePESSTO+) or the aforementioned Very Large Telescope (VLT), also in Chile.
How many types of supernovae are there?
There are two known types of supernova: thermonuclear and gravitational. The first type occurs in binary star systems when one of the two stars, a carbon-oxygen white dwarf, steals matter from its companion star. At some point, the white dwarf accumulates too much matter and the star explodes, eventually becoming a supernova. Supernovae leave behind compact objects in the form of neutron stars or even black holes.
The second type of supernova occurs at the end of the life of a single star; As the star runs out of nuclear fuel, some of its mass flows into the core until the core becomes so dense that it can’t withstand its own gravitational pull and collapses, leading to another brutal explosion. Gravitational supernovae are technically type II, Ib, Ic…
Who coined the term supernova?
As a curiosity, the term supernova was coined by the German astronomer Walter Baade (who discovered ten asteroids, among other things) and the Swiss astronomer and physicist Fritz Zwicky in 1931 to name the most luminous stellar phenomena (the less luminous ones continued to be called simply ” novae” or “nova”). Supernova means “above a nova.”
Reference: ESO / Inserra et al., Amram et al. eso.org/public/spain/images/potw2210a/
