Simultaneous Multi-band Optical Follow-up Observations of a Gamma-Ray Flare in BL Lacertae

X. Chang, D. R. Xiong, Chenxu Liu +17

On $2024$ October $5$, BL Lacertae ($2200+420$) experienced one of its brightest gamma-ray flares. We conducted simultaneous follow-up observations in the $u$, $v$, $g$, $r$, $i$,…