Millions of years ago, before Earth joined Earth’s North and South American continents, about 21 million light-years away, an aged, bloated star dramatically passed away, dying in a cataclysmic supernova explosion.
On Friday, May 19, the light from this massive explosion finally reached the telescope of Japanese amateur astronomer Koichi Itagaki, who alerted the entire astronomical community: the supernova is now officially called SN2023ixf.
“These photons that left that exploding star 20 million years ago have just slammed into our shores after that long, long journey through the cosmos,” said Grant Tremblay, astrophysicist at the Harvard and Smithsonian Institute Center for Astrophysics, who has been actively working to spread word of the supernova on social media. “It’s happening now, in that we’re watching this thing finally explode, but the star has been dead for 20 million years.”
SN2023ixf is the closest such supernova to Earth to erupt in five years, and the second closest in the past decade, according to NASA. This makes SN2023ixf a rare opportunity for astronomers to study the fiery death of a star. Although too faint to see with the naked eye, the supernova should be visible with modest amateur telescopes, according to Tremblay.
Because the supernova will fade quickly, astronomers must seize the opportunity to observe it, including at multiple wavelengths.
How to spot supernova SN2023ixf
SN2023ixf exploded in M101, also known as the Pinwheel Galaxy, located in the night sky near the constellation Ursa Major. M101 is a bright spiral galaxy that sits face-to-face from Earth’s perspective and is part of the Messier catalog of celestial objects, making it a common target for backyard astronomers. A 4.5-inch telescope should be enough to view the supernova, which will appear as a bright point of light, according to Sky and Telescope. You can find M101 by first finding Mizar, the star at the bend of Ursa Major’s tail, and following the five stars away from it. Or, to be more precise, you want to point your telescope at a right ascension of 14:03:38.580 and a declination of +54:18:42.10.
[Related: Astronomers just confirmed a new type of supernova]
Alternatively, the Virtual Telescope Project, a global network of quality amateur telescopes, will livestream a supernova sighting beginning at 12:00 p.m. Eastern Time on May 26.
“M101 is imaged by human beings every night, all over the world, from amateurs to all sky observatories like [The Sloan Digital Sky Survey], and so it was inevitable that this thing would eventually be found. But I loved that Itagaki found another supernova,” says Tremblay. Itagaki is not a professional scientist, but he has co-authored more than a dozen scientific papers based on his supernova observations. Tremblay says Itagaki has a “legendary” ability to spot supernovas, and he collects such “discoveries like Thanos and the Infinity Stones.” Itagaki’s discoveries include the supernova 2018 SN 2018zd, which turned out to be an entirely new type of supernova in the universe.
Astronomer Koichi Itagaki sighted the supernova (denoted by the two straight lines) in the Pinwheel galaxy. Koichi Itagaki
Catching the bright shard of SN2023ixf on May 19, Itagki submitted his discovery to the International Astronomical Union’s Transitional Name Server website. From there, professional astronomers answered the call, and within days researchers began pointing to the supernova from major ground and space telescopes, including the Hubble and James Webb Space Telescopes and the Chandra X-ray Observatory. .
All of these telescopes will measure the light curve of SN2023ixf, “meaning the brightening and fading of this target in multiple wavelengths,” says Tremblay, on the optical light X-ray spectrum in passing through the infrared.
The lessons of an exploded sun
These observations will help scientists characterize the star that exploded to create SN2023ixf, and further define what type of supernova it is. Astronomers can already tell that SN2023ixf is a Type II supernova, or “core meltdown.” This happens when a massive star exhausts its nuclear fuel. Nuclear fusion reactions in its core can no longer push outward against the star’s gravitational force. The star’s core collapses in on itself, then explodes outward in less than a second.
“This shock wave propagates outward and lifts gas into the ambient environment that can ignite in all different wavelengths,” says Tremblay. Studying how this afterglow changes over time will tell scientists about the late star’s mass and composition.
And the composition of the star is tied to life on Earth – and life anywhere else in the cosmos, if it exists. Stars increase in chemical complexity throughout their life cycle: they formed from primordial hydrogen after the Big Bang, fusing it first into helium, then into heavier elements up to iron. When these stars die in supernovae, the intense heat and pressure form all known elements heavier than iron and seed them throughout the cosmos, providing the raw material for rocky planets and life itself. “The story of life in the universe can be reduced, in many ways, to the story of increasing complexity,” says Tremblay.
The explosion of SN2023ixf literally shines a light on the process that gave birth to the human being. Although the supernova will fade quickly, it will remain an object of study for years to come, according to Tremblay. In the meantime, he says, the global excitement around the supernova “is a great illustration of how global audiences so easily share in our wonder of the cosmos.” An exploding star in a distant galaxy illuminates people’s hearts. »
