Аннотация:MASTER OT J211855.08+280314.9 - new CV MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 21h 18m 55.08s +28d 03m 14.9s on 2013-03-30.81471 UT. The OT unfiltered magnitude is 16.3m (limit 17.3m). The OT is seen in 4 images. We have reference image without OT on 2012-08-22.74248 UT with unfiltered magnitude limit 19.1m. The OT has brightened to 15.7m on MASTER-Amur image of 2013-03-31.819 UT.