The 2021 outburst of the symbiotic star YY Her
ATel #14458; Kirill Sokolovsky (MSU/SAI MSU), Stanislav Korotkiy (Ka-Dar Obs./Astrovert), Olga Smolyankina (Observatory of Omsk CPCT), Aleksandr Beloushkin (Voronezh), Elias Aydi, Laura Chomiuk, Adam Kawash, Jay Strader (MSU)
on 15 Mar 2021; 17:04 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
Subjects: Optical, Cataclysmic Variable, Nova, Star, Variables
The symbiotic star YY Her is found in outburst at the unfiltered magnitude
(V zero-point) CV=11.87 on 2021-03-15.006 UTC. The images were obtained with
the NMW wide-field camera: Canon 135mm f/2.0 telephoto lens + ST-8300M CCD
(Sokolovsky at al. 2014, ASPC, 490, 395). These are the first NMW images
of the field in the current observing season. Previously YY Her was
typically found around CV~13.
The ASAS-SN (Shappee et al. 2014, ApJ, 788, 48; Kochanek et al. 2017, PASP,
129, 104502) photometry shows the rapid increase in brightness of YY Her
started around 2021-02-25.60 at g=13.34 reaching g=12.62 by 2021-03-08.380.
The previous outburst of YY Her was observed in 2013 (ATel #4996).
We thank the AAVSO observers for a continuous coverage of YY Her variations
in the previous decades providing a great comparison baseline for
the new observations.
The ASAS-SN lightcurve of YY Her
