Now could be a great time to have a look at a well-known galaxy in Ursa Major if you have access to a telescope. If you don’t have access and know someone who does, ask to peek at theirs. It’s not every day that you get to witness a massive star erupt and glow brighter than a billion Suns. A moderately big telescope was required to glimpse the new supernova when it made headlines, but a small telescope may now detect it under dark skies.
Japanese astronomer Koichi Itagaki reported a likely supernova (designated SN 2023ixf) in the Pinwheel Galaxy (commonly known as Messier 101) late last week, and astronomers using the 2-meter Liverpool Telescope confirmed this. You’ve probably seen pictures of the Pinwheel even if you haven’t heard of it. This galaxy has been a popular subject for astrophotographers because of its nearly flawless spiral structure, face-on orientation to Earth, and proximity (21 million light-years).
Hubble and Swift space telescopes have shifted their focus from previously scheduled observations to SN 2023ixf, resulting in a deluge of data that will take months or even years to analyze and publish. The team that verified the supernova’s status concluded their report with the words “Additional follow-up is encouraged.” They have had no trouble finding amateur and professional enthusiasts, thanks to the Pinwheel’s constant visibility across most of the Northern Hemisphere.
One who has already answered the call is the astrophotographer Andrew McCarthy, who is known for his amazingly detailed photographs generated by merging multiple images. Funny enough, McCarthy thinks this view of the Pinwheel, with the supernova shining brightly in the upper arm, is subpar. McCarthy explains that the Pinwheel is a cluster of stars so dense that no individual stars can be seen within it. All of the other stars in the image are from our own galaxy.
Initial confirmed observations put its brightness at 16, but by the time word spread, it had dropped to 14 (lower magnitudes indicate greater brightness). That is on the very edge of what a moderately sized telescope can view from home in dark skies. Over the past few days, the brightness has stabilized at 11th magnitude, well within the range of beginner telescopes. Expectations that it will brighten to the point that binoculars might be used to observe it (about 9th magnitude) appear to be unfounded.
Since 1900, five supernovae and one magnificent nova have occurred in the Pinwheel. The Milky Way’s partner is really showing us up because there hasn’t been a confirmed supernova in 400 years. Although the Pinwheel galaxy only has a star count 2-10 times that of our own, it is far more active in producing new stars, presumably as a result of powerful gravitational interactions with its smaller companion galaxies.
SN 2011fe was one of the four nearest supernovae to Earth this century. Type Ia supernovae (white dwarfs) 2011fe and SN 2014J were similar in many ways. As a result, SN 2023ixf is the nearest example of a confirmed Type II supernova since 2004 (when 2011fe became the norm against which more distant Type Ias are assessed). From 10:30 pm UT on May 26, the Virtual Telescope Project will be streaming a live feed of the telescope so that people who don’t have access to a telescope or who can’t get away from city lights can observe it remotely.