The predominant solar active region AR 4473 in action
ATel #17851; Costantino Sigismondi (ICRANet Pescara and UPRA-SFI Roma, Italy)
on 21 Jun 2026; 12:41 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Costantino Sigismondi (sigismondi@icra.it)
Subjects: Radio, Optical, X-ray, The Sun
Referred to by ATel #: 17852
The solar activity in the last 5 months has been characterized by the apparition of some "predominant active regions", capable of releasing a sequence of relatively intense and frequent flares (e.g. AR 4366 at the beginning of February 2026 [ATel#17644], AR 4420 at end April 2026 and AR 4455 at the beginning of June 2026). The duration of these intense activities resulted limited to three days. Within this time interval almost all solar flares in the Earthside hemisphere are produced by the predominant region. Some of the flares can be as intense as X-class. AR 4473, started to flare on 20 June 2026 at the Eastern solar limb, it is one of these predominant regions.
Its solar activity peaked already with M1 and M2.7 flares, and it can produce more strong flares nearly each 12 hours, as suggested by the GOES X-ray flux analysis.
The first day of activity of AR4473 (composite, souorce GOES/NOAA and LMSAL)
