A nearby supernova may peak November 18-23, and amateur telescopes can already show it, NOIRLab says

A star that blew itself apart in the barred spiral galaxy NGC 1433 is still brightening, and NSF NOIRLab expects it to top out between November 18 and 23. In a photo release on November 12, 2026, the US National Science Foundation's center for ground-based optical-infrared astronomy said the supernova, SN 2026ahvu, should then reach magnitude 10.5 to 12.1, and that people with modest amateur telescopes can already pick it out when conditions are good. Both figures are estimates that may change as observations continue, NOIRLab stresses.

Found early, still brightening

The Asteroid Terrestrial-impact Last Alert System, or ATLAS, logged the discovery at about 04:20 UTC on November 2. Spectra taken the next day with the DEIMOS instrument on the Keck II telescope identified a young Type Ia supernova, and the object, first designated AT 2026ahvu, was renamed with the SN prefix. It stood at about magnitude 17 when found and had been reported at 13.5 within days, according to NOIRLab. Magnitudes run backward: the lower the number, the brighter the object.

Where it is, and who can see it

NGC 1433 lies in Horologium, the Pendulum Clock, a constellation of the southern sky. NOIRLab gives the supernova's position as right ascension 03h 41m 55.511s and declination −47° 13′ 39.39″ (J2000); in its images the new point of light sits to the right of the galaxy's center and slightly below it. That southern position makes it difficult or impossible to observe from far northern latitudes, the release says, while it is easiest "from southern locations where NGC 1433 rises high in the sky."

By our calculation from that declination, ignoring the atmosphere and local terrain, the supernova never rises above a flat horizon north of about latitude 43 degrees north. From latitude 30 degrees north it climbs no higher than about 13 degrees, while from 34 degrees south it passes about 77 degrees above the horizon.

Visibility also depends on the telescope's aperture, the darkness of the sky and the atmosphere, NOIRLab says, and a camera can record the supernova through a smaller telescope than the eye needs. Moonlight will not help: the US Naval Observatory puts first quarter at 11:48 Universal Time on November 17 and full Moon at 14:53 UT on November 24, so by our reading the predicted peak falls in the week the Moon is waxing from half to full.

Why a nearby Type Ia matters

A Type Ia supernova is the thermonuclear destruction of a white dwarf, the dense remnant of a star like the Sun, that has drawn matter from a close companion. Their intrinsic brightness is well known, which is why astronomers use them as standard candles to measure distances, and NOIRLab says pinning down this one's peak apparent brightness will improve the distance to NGC 1433. The release adopts about 50 million light-years and notes that published estimates differ.

Catching one before maximum matters because clues to how the white dwarf ignited, and to any companion star or surrounding material, can vanish quickly as the debris expands. NOIRLab calls SN 2026ahvu one of the nearest Type Ia supernovae observed since SN 2011fe, which appeared in the Pinwheel Galaxy, Messier 101, in 2011. NASA puts the Pinwheel at 25 million light-years, so by our comparison the new supernova's host galaxy is about twice as far away.

There is a before picture, too: the Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope in Chile imaged NGC 1433 during the Dark Energy Survey, which ran from 2013 to 2019. NOIRLab is now coordinating follow-up with the Blanco telescope, Gemini and the SOAR telescope on Cerro Pachón, tracking the supernova's brightness and color and taking spectra that show what the debris is made of and how fast it moves. It has invited other observatories to join, and the Gemini data, taken under Director's Discretionary Program GS-2026B-DD-104, are public in the Gemini Observatory Archive.

What comes next

NOIRLab plans to follow the explosion through its peak and into its long fade. Maximum light can come at different times in different observing filters, it notes, so the peak is not one moment for every instrument. For the month's other sights, see our guide to the late November sky.