In recent days, astronomers around the world have been pointing their telescopes towards a new celestial object. In our spring sky, a supernova has appeared, named SN2023ixf, a star that has literally exploded before our eyes.
The supernova has appeared in a galaxy known as the Whirlpool Galaxy (M101), a large spiral galaxy. The brightness of the supernova is so high that it can be observed through a small telescope and with the help of low-power eyepieces, if the sky is dark enough.
How to observe the supernova
Long-exposure astrophotography will easily reveal the spiral arms of this galaxy. In some of these images taken in recent days, the new celestial body is clearly visible. The Whirlpool Galaxy containing the new supernova is located near the boundary that separates Ursa Major from Boötes the Herdsman. To locate it manually, one must imagine a line extending from two stars in the handle of the Big Dipper, Alioth and Mizar, and continue for a similar distance beyond Mizar.
More experienced astronomers familiar with observing M101 may visually see the supernova as a dot of light out of place in one of the spiral arms. However, M101 and the supernova are not the easiest objects to spot in the sky. Part of the reason is their apparent size, as M101 is about one-third of the apparent diameter of the Moon.
This supernova was many times larger than our Sun. If a star of this size were to replace our Sun in the Solar System, it would extend far beyond the orbit of Mars. The fascinating phenomenon visible these days actually occurred a long time ago. Since M101 is located approximately 21 million light-years away from Earth, the light of the explosion has traveled through space for 21 million years before finally reaching our planet.
How long will the phenomenon last
Astronomers will certainly continue to monitor the supernova in the coming days, noting any fluctuations in brightness. If enthusiasts have not yet had the opportunity to observe the exploded supernova in the galaxy M101, the phenomenon should last another year, perhaps more. Scientists expect it to fade slowly until it can no longer be observed in the visible spectrum.
Sky observers and astrophotographers also expect the supernova to be visible for some time. “We expect the brightness to remain stable for weeks, if not months” said Daniel Perley, an astrophysicist at the John Moores Observatory in Liverpool. The supernova is one of the largest and brightest seen in the last decade, but its light will tend to weaken. “Over the next year, two, or three years, it will finally fade back to a low detectability” Perley said.
Peter Brown, a researcher at Texas A&M Supernova, states that most normal Type II supernovae, like SN2023ixf, have a constant brightness for about 100 days before starting to decline. But according to Brown, this is a special case. Most Type II supernovae drop sharply into the ultraviolet range. SN2023ixf, on the other hand, has remained consistently bright, saturating observations made with NASA‘s multi-wavelength Swift space telescope.
Study with space telescopes
Supernovae shine as the material ejected from the star interacts with the surrounding environment. So even as it begins to fade, SN2023ixf could reignite if it interacts with denser clouds or shells surrounding the dying star. Even after it can no longer be seen in visible wavelengths, the supernova will likely continue to shine in other parts of the spectrum.
Brown stated that large telescopes should be able to observe the exploded supernova for years, while space instruments like the Hubble telescope or the James Webb Space Telescope could potentially study the explosion for decades. “The phenomenon could still surprise us. We don’t know for sure” Perley concluded.”