TITLE: GCN CIRCULAR NUMBER: 27744 SUBJECT: GRB 200514A: MITSuME Akeno optical upper limits DATE: 20/05/15 15:35:39 GMT FROM: Adachi Ryo at Tokyo Institute of Tech N. Nakamura, R. Hosokawa, R. Adachi, K. L. Murata, M. Niwano, F. Ogawa, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We performed tiling observation for the MAXI/GSC error region of GRB 200514A (Y. Okamoto et al., GCN Circular #27735; Ricciarini et al., GCN Circular #27743) with an optical tri-color (g', Rc, and Ic) camera attached to the MITSuME 50cm telescopes at Akeno Observatory in Japan. The follow up observation started at 2020-05-14 10:36:15 UT, 495 minutes after the trigger. Our tiling observation covered almost ~65% of the MAXI/GSC error region (GCN Circular #27735). Compared our co-added images with the GSC2.3 and UCAC4 catalogs, we found no bright optical transient in the observed region except a high proper motion star (R.A.=11:20:26.73, Dec.=+19:53:14) listed in the NEOWISE/AllWISE high proper motion objects (Schneider et al. 2016). Because the elevation of the target field had dropped from 75 deg to 16 deg during the observations and the sky condition was unstable, the obtained upper limits are different for each field. The 5-sigma upper limits of the co-added images are listed below. Field num. | center position(R.A., Dec.) | size of field(R.A.(arcmin) x Dec.(arcmin)) | 5-sigma upper limit | MID-UT(UT) | exposure time(sec) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Field 0 | 11:21:03, +19:43:24 | 24.9 x 25.9 | g' > 18.4, Rc > 18.2, Ic > 16.5 | 12:24:50 14 May | 870 Field 1 | 11:19:53, +19:52:19 | 25.6 x 26.1 | g' > 18.0, Rc > 17.7, Ic > 16.9 | 12:35:31 14 May | 480 Field 2 | 11:20:25, +19:26:36 | 25.8 x 25.9 | g' > 16.8, Rc > 16.7, Ic > 16.1 | 12:44:04 14 May | 1170 Field 3 | 11:19:15, +19:35:00 | 25.7 x 26.0 | g' > 18.3, Rc > 17.9, Ic > 17.1 | 12:05:44 14 May | 660 Field 4 | 11:21:41, +19:59:30 | 25.6 x 26.1 | g' > 17.8, Rc > 17.6, Ic > 16.7 | 11:18:32 14 May | 360 Field 5 | 11:20:30, +20:08:15 | 25.6 x 25.9 | g' > 18.0, Rc > 17.4, Ic > 16.8 | 12:33:09 14 May | 570 Field 6 | 11:19:49, +19:09:39 | 25.7 x 25.9 | g' > 18.7, Rc > 18.3, Ic > 17.5 | 12:11:34 14 May | 660 Field 7 | 11:18:42, +19:18:54 | 25.7 x 26.1 | g' > 18.0, Rc > 17.6, Ic > 16.8 | 11:26:50 14 May | 210 Field 8 | 11:21:55, +20:24:47 | 25.9 x 26.0 | g' > 17.1, Rc > 17.0, Ic > 15.9 | 16:21:30 14 May | 150 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- We used the UCAC4 catalog for the flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al., in prep; https://github.com/MNiwano/Eclair).