A supernova called SN 2023ixf appeared on the outskirts of a beautiful spiral galaxy in the night sky.
An exploding supergiant star – the result of its core collapsing under its own gravity – can be seen in the night sky, but it takes more than a clear sky and wide eyes to see it.
“You will not be able to see this supernova with the naked eye,” he wrote Andy Howellastronomer from Las Cumbres Observatory, on Twitter. “For that you need a supernova in our galaxy or a satellite galaxy in close proximity.”
SN 2023ixf is located in the Pinwheel Galaxy (M101), a particularly beautiful galaxy very close to the handle of the Big Dipper. Even if there wasn’t a supernova, it’s worth targeting with a telescope.
That’s because M101 is a large spiral galaxy, with arms full of stars. From the solar system we get a face-on view of it from above/below.
SN 2023ixf itself is just a point of light, but it currently outshines anything else in the galaxy. “This new supernova will increase in brightness over the coming days,” Howell wrote. “We should be able to see it with backyard telescopes for a few months.”
A rare sight
Supernovae are relatively rare and can almost always be seen in other galaxies.
The best view modern astronomers ever had of a supernova was in 1987 when a giant star exploded in the Large Magellanic Cloud (LMC), a dwarf galaxy orbiting our Milky Way galaxy. The LMC is easily visible from the Southern Hemisphere, so SN 1987A gave astronomers a rare opportunity to study the phases before, during and after the star’s death.
Nothing has come close since. In fact, a supernova has not been seen within the Milky Way since 1604, when German astronomer Johannes Kepler observed one shining in daylight for three weeks.
Supernovae may be rare near the Solar System, but they’ve left their mark all over the night sky.
The most famous supernova seen from Earth occurred in 1054. Its remnants can still be seen as the Crab Nebula (M1) in the constellation Taurus.
A cloud of gas and dust expanding into space with a rotating pulsar at its core, we know humans have seen it because records of the appearance of a “guest star” have been found in East Asian texts.
Supernova 1054—which shone for 23 days and was 10 times brighter than Venus—could also be shown in the pictograph in the southwestern United States. Image in Chaco Canyon, New Mexico created on a rocky outcrop by the ancestral Puebloan culture, depicts a star shape next to a crescent moon below a life-size handprint. This coincides with the exact predicted date of the supernova – July 4, 1054 – when, the following night, the moon was only three degrees from where the supernova would be.
Early warning system
Can one speculate whether a star in the Milky Way is about to go supernova? A prime candidate is Betelgeuse, the closest red supergiant star to the Solar System at about 550 light-years, which is expected to go supernova in the next 100,000 years. That showed some strange behavior in 2019-2020, but it did not explode.
When a nearby star explodes, we can get some warning. Modern neutrino detectors should be able to detect a neutrino-ejecting star moments before it collapses in a supernova explosion. Supernovae are thought to be the most common source of cosmic neutrinos in the universe.
With a “kill zone” for a supernova about 40 light-years away, Earth will be safe—and we’ll all get a great naked-eye view of the bright “guest star” in daylight. Until then, enjoy SN 2023ixf through any small telescope.
I wish you clear skies and wide eyes.
Forbes – Innovation