LIGO/Virgo S230615an: Global MASTER-Net observations report

MASTER-OAFA robotic telescope (Global MASTER-Net : http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the LIGO/Virgo S230615an errorbox 1 days 54971 sec after notice time and 1 days 55025 sec after trigger time at 2023-06-17 04:52:27 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 47 deg. The sun altitude is -81.5 deg. The galactic latitude b = 13 deg., longitude l = 288 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=12040 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 141515 | 2023-06-17 04:52:27 | MASTER-OAFA | (14h 21m 06.69s , -64d 38m 49.5s) | C | 180 | 17.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.