OGLE-IV Pre-discovery Observations of MASTER OT J051032.58-692130.4
ATel #9040; P. Mroz, A. Udalski, L. Wyrzykowski, M. Pawlak (Warsaw University Observatory), on behalf of the OGLE team
on 11 May 2016; 17:23 UT
Credential Certification: Przemek Mroz (firstname.lastname@example.org)
Subjects: Optical, Nova, Transient
Referred to by ATel #: 9048
Gorbovskoy et al. (ATel #9039) reported the discovery of a bright optical transient MASTER OT J051032.58-692130.4 toward the Large Magellanic Cloud. The object is located in the field LMC509 that is regularly monitored by the OGLE-IV Survey.
The star was severely saturated in the image acquired on 2016 April 28.97626 UT, meaning it was brighter than I=11 mag. The last pre-eruption image was taken eight nights earlier (on April 21.00403 UT).
The progenitor was clearly visible in the OGLE images at equatorial coordinates of R.A. = 05:10:32.63, Decl. = -69:21:30.4 (J2000.0). It had the mean magnitude of I = 20.64 mag and color (V-I) = 0.27 mag and showed eclipsing-like variability with a period of 2.6508 +/- 0.0002 d. The star has been monitored by the OGLE since 1997 and we did not recorded any other eruptions.
The transient's brightness and its progenitor's properties suggest it is a classical nova.
Finding charts can be found here.