RW Cephei great dimming
ATel #15800; Wolfgang Vollmann (AAVSO/BAV, Vienna) and Costantino Sigismondi (ICRANet/AAVSO, ITIS G. Ferraris, Rome)
on 9 Dec 2022; 12:54 UT
Credential Certification: Costantino Sigismondi (sigismondi@icra.it)
Subjects: Optical, Variables
RW Cephei is a red hypergiant normally ranging between magnitudes 6.0 and 7.3.
From the AAVSO light curves of the star are evident semi-regular fluctuations within the above range, but since 2022 the star is significantly dimming, instead of rebrightening, and reaching already the magnitude V=7.6.
The comparison star of the DSLR series of measures from 2020 is HD211982 which is V=7.298.
The V magnitude observations of the Kiso/Kyoto Wide Field Survey (KWS) confirm the quick fade in 2022 like AAVSO visual (since 1977, VOL observer code) and DSLR measures made in Vienna with 75 mm lens.
This phenomenon undergoing on RW Cep might be similar to the one occurred to the red supergiant Betelgeuse at the end of 2019 (ATel #13341, ATel #13601).
(for KWS see Maehara, H. (2014) Automated Wide-Field Survey for Transient Objects with a Small Telescope. Journal of Space Science Informatics Japan, 3, 119-127)
RW Cephei light curves from 2009 till 2022
