Data sources:

A5: BVRcIc photometry by V.P.Goranskij and E.A.Barsukova with the 50-cm Maksutov telescope AZT-5 of the Moscow University Crimean Astronomical Station and CCD Apogee-Alta U8300.
As: UBVRcIc photometry by A.V.Zharova with the 60-cm telescope of the Moscow University Crimean Astronomical Station and CCD Apogee Aspen.
AT: D.Denisenko, Astronomer's Telegram #11400, 2018.
C.Litterfield, Astronomer's Telegram #11421, 2018.
P.Gandhi, J.A.Paice, S.P.Littlefair, V.S.Dhillon, P.Chote, T.R.Marsh, Astronomer's Telegram #11437, 2018.
M.Richmond, Astronomer's Telegram #11596, 2018.
M.C.Baglio, D.Russell, T.Al Qaissieh, A.Palado, A.Gabuya, H.Shivkumar, F.Lewis Astronomer's Telegram #12128, #12596, 2018.
J.Ulowetz, G.Myers, J.Patterson, Astronomer's Telegram #12567, 2018.
U.Munari, L.Zampieri, P.Ochner, F.Manzini, Astronomer's Telegram #12608, 2018.
MM: V.P.Goranskij with the SAO 1-m Zeiss Telescope and the MMPP photometer polarimeter.
SO: UBVRc photometry made by E.A.Barsukova and V.P.Goranskij with CCD EEV 42-40 at 1-m Zeiss telescope of the Special Astrophysical Observatory, Russia.
SV: UBVRcIc photometry made by S.Yu.Shugarov with the 60-cm Zeiss G2 telescope of the Stara Lesna Observatory (Slovakia) and FLI-2 CCD.