A million years ago, before land joined the North and South American continents, about 21 million light-years away, an aged and bloated star gave up the ghost in dramatic fashion, dying in a cataclysmic supernova explosion.
On Friday, May 19, light from that massive explosion finally reached the telescope of amateur Japanese astronomer Koichi Itagaki, who alerted the wider astronomical community: The supernova is now officially named SN2023ikf.
“Those photons that left that exploding star 20 million years ago just washed up on our shores from this long, long journey through the cosmos,” says Grant Tremblay, an astrophysicist at Harvard and the Smithsonian Institution’s Center for Astrophysics, who has been actively spreading the word about the supernova. on social networks. “It’s happening now, when we’re watching this thing finally explode, but the star has been dead for 20 million years.”
SN2023ikf is the closest supernova of its kind to Earth in the last five years, and the second closest in the last decade, according to NASA. This makes SN2023ikf a rare opportunity for astronomers to study the fiery death of a star. Although too faint to be seen with the naked eye, the supernova should be visible with modest hobbyist telescopes, according to Tremblay.
Because the supernova will fade quickly, stargazers must take advantage of the opportunity to observe it, including at multiple wavelengths. “The entire global community has come together, from community astronomers to large, multibillion-dollar space telescopes,” says Tremblay.
How to spot supernova SN2023ikf
SN2023ikf exploded in M101, also known as the Pinwheel Galaxy, located in the night sky near the constellation Ursa Major. M101 is a bright face-on spiral galaxy from Earth’s perspective and a member of the Messier Catalog of Celestial Objects, making it a common target for backyard astronomers. A 4.5-inch telescope should be enough to see the supernova, which will appear as a bright point of light, according to The sky and the telescope. You can find M101 by first finding Mizar, the star at the bend in the tail of the Big Dipper, and following the five stars leading 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 worldwide network of quality amateur telescopes, will broadcast a live view of the supernova starting at 12pm Eastern on May 26.
“M101 is recorded by human beings every night, all over the world, from hobbyists to all the celestial observatories like [The Sloan Digital Sky Survey], so it was inevitable that this thing would eventually be found. But I just 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 supernovae and collect these “discoveries like Thanos and the Infinity Stones.” Itagaki’s findings include the 2018 supernova SN 2018zd, which turned out to be an entirely new type of supernova in the universe.
Astronomer Koichi Itagaki spied a supernova (marked by two straight lines) in the Pinwheel galaxy. Koichi Itagaki
Catching the bright explosion of SN2023ikf on May 19, Itagki posted his discovery to the International Astronomical Union’s transient name server website. From there, professional astronomers took up the call, and within days researchers began pointing major ground-based and space-based telescopes at the supernova, including the Hubble and James Webb Space Telescopes and the Chandra X-ray Observatory.
All of those telescopes will measure the light curve of SN2023ikf, “which means the multi-wavelength brightening and fading of this target,” says Tremblay, across the spectrum from X-rays to optical light to infrared.
Lessons from the exploded sun
These observations will help scientists characterize the star that exploded to create SN2023ikf, and more precisely define the type of supernova. Astronomers can already say that SN2023ikf is a type II, or “core collapse” supernova. This happens when a massive star exhausts its nuclear fuel. The nuclear fusion reactions in its core can no longer push outward against the force of the star’s own gravity. The star’s core collapses in on itself and then explodes outward in less than a second.
“This shock wave propagates outward and ejects gas in the ambient environment that can glow at all different wavelengths,” Tremblay says. Studying how that afterglow evolves over time will tell scientists about the mass and composition of the deceased star.
And the composition of a star is linked 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 and then into heavier elements up to iron. When those stars die in supernovae, the intense heat and pressure form all known elements heavier than iron and seed them across 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 a story of increasing complexity,” says Tremblay.
The SN2023ikf explosion literally sheds light on the process that brought human beings into being. Although the supernova will fade quickly, it will remain the subject of study for years to come, according to Tremblay. In the meantime, he says, the world’s supernova excitement “is a beautiful illustration of the fact that the global public is so effortlessly sharing our wonder of the cosmos.” An exploding star in a distant galaxy just lights up people’s hearts.”