The brighter phase of Betelgeuse since 2017

ATel #15240; Costantino Sigismondi (ICRA/Sapienza University of Rome and ITIS G. Ferraris, Rome), Wolfgang Vollmann (AAVSO/BAV), Fabio Mariuzza, Rod Stubbings (AAVSO), Otmar Nickel (University of Mainz and AAVSO/BAV), Sandip V. George (University of Groningen) and Remo Ruffini (ICRANet Pescara)
on 25 Feb 2022; 00:32 UT
Credential Certification: Costantino Sigismondi (sigismondi@icra.it)

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The great dimming of Betelgeuse in February 2020, was accounted starting with the ATel #13341 of 8th December 2019, and a second dust-cloud minimum occurred in August 2020 ATel #13982. After that the luminosity of Betelgeuse underwent small (0.1 mag) oscillations around the visual magnitude 0.65; now the star had a rapid rising particularly evident in the last weeks, reaching Procyon in luminosity near magnitude 0.3. This is the brighter phase after 2017, five years, in fair agreement with the modulating period of Betelgeuse of 5.9 years. The Purkinje effect, which enhances red stars' luminosity to the naked eye, has been avoided in the visual observations with quick-look techniques and with the differential analysis with Aldebaran, of the same color. Airmass corrections have been always included (AAVSO database- https://www.aavso.org/lcg - SGQ, MFB and SRX codes). The V-Band observations showed an overall 0.006 mag/day rising in the last 7 weeks (AAVSO-VOL code). This could be the maximum phase before reaching a new minimum next June 2022, if the pulsations are in phase with the usual period of 1.2 years. The V-band observations in daytime (AAVSO-NOT code) monitored the star in June-August 2021 providing a seamless lightcurve, and this technique can provide data for the forthcoming minimum. Anyway the present rising is not in phase with respect to the 2020's one, accounted in ATel #13601 on March 31, within the usual (until 2020 at least) pulsational regime of 1.2 years. Some evidences of such behavior have been already presented at the XVI Marcel Grossmann Meeting HR1 session, online at https://youtu.be/VmbrE2gYmOM in July 2021, with interesting observational and theoretical discussions.

MG XVI session on Betelgeuse Fall and Rise (2021)