X-flaring active region at the solar western limb: possible SEPs event
ATel #17494; Costantino Sigismondi (ICRANet, Pescara and UPRA, Roma)
on 15 Nov 2025; 19:53 UT
Credential Certification: Costantino Sigismondi (sigismondi@icra.it)
Subjects: Optical, Ultra-Violet, X-ray, Gamma Ray, >GeV, The Sun
The propensity of the Active Region AR 14274 to produce Long Duration Events has been clear since its appearance at the solar Eastern limb. The events M5 of 3rd November 2025 and, more evidently, X1.2 of 10 November, with the acceleration of solar energetic particles (SEPs) have been registered by the Space Weather satellites, and the Observatories all around the World.
The increasing intensity of the major flares followed a regular time pattern, with a periodicity near 24 hours, with largest flares occurring after a "charging time" nearly exact multiple of this characteristic time. The sequence of the major flares has been up to now
X1.8 (4 Nov), M7.5-M8.6 (5 Nov), X1.7 (9 Nov), X1.2 (10 Nov), X5.1 (11 Nov) and X4.0 (14 Nov).
The largest X-class flares produced aurorae on 12 November 2025 even at Mediterranean regions (see ATel #16635) and significant proton fluxes, the first SEPs events of 2025, after two events on 8 June 2024 and 21 November 2024, both geo-effective, with the emitting regions near the Western limb.
These Space Weater events are harmful for astronauts and satellite payloads.
Due to the energetics and the regularity of this flaring Active Region AR14274, it is reliable to expect another X-class event with SEPs at the Western limb, geo-effective, around X5 class, especially if released as late as 17 November 2025.
There is chance also of seeing the flare in white light, during the peak phase, as it may have occurred to observers like Christopher Scheiner (1573-1650) and Athanasius Kircher (1602-1680) well before the 1859-Carrington event (cfr. Histories, 5, 48, 2025 https://www.mdpi.com/2409-9252/5/4/48).
Flares and aurorae from AR 4274 at ICRANet-Pescara, Italy
