Optical follow-up of MASTER OT J210334.55+234128.9
ATel #5127; R. Nesci (INAF/IAPS, Roma), A. Caravano, V. Falasca (Oss. Cittadino, Foligno)
on 13 Jun 2013; 05:48 UT
Credential Certification: Roberto Nesci (Roberto.Nesci@iaps.inaf.it)
Subjects: Optical, Cataclysmic Variable, Transient
Following the request in ATel #5122 we observed the optical transient MASTER OT J210334.55+234128.9 with the 30 cm F/10 Schmidt-Cassegrain telescope of the Foligno Observatory in the V filter and 1800 s exposure on 2013-06-12.916 UT. Aperture photometry was performed with IRAF/apphot, using 37 comparison stars from UCAC4 catalogue within the field of view.
The star was detected at V=17.3 +-0.1, which is 2.5 mag fainter than the discovery value. The fading slope (0.78 mag/day) is therefore even steeper than that typical of SS Cyg (0.36 mag/day) or U Gem (0.57 mag/day). This support the suggestion in ATel #5122 that this source is likely a dwarf nova of the U Gem type.