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GCN Circular 18533

GRB 151027A: Optical counterpart detection
2015-10-29T21:34:24Z (9 years ago)
Valentyna Golovnya at Main Astro Obs,Kyiv <>
Yu. Protsyuk (RI NAO), O. Kovalchuk (RI NAO) report: 

    We observed the field of the Swift GRB 151027A (Maselli et al. 
    GCN 18478) with 0.5-m telescope Mobitel KT-50 of Nikolaev observatory 
    with Alta-U9000 CCD-camera with R filter in robotic mode 
    from Oct., 28 (UTC) 20:34:16 till 20:59:59. 
    We obtained 19 unfiltered images of 60 s exposure and calculated 
    coordinates and magnitudes of all detected objects in UCAC4 system. 
    We don't detect any optical counterpart of GRB 151027A (Maselli et al. 
    GCN 18478; Zheng and Filippenko, GCN 18479) in coordinates near (J2000) 
    18 09 56 +61 21 12 up to ~17.2- 17.5 m . 
    After that we filtered all images and detected optical 
    counterpart��in 6 images��in coordinates (J2000) 
    18 09 56.680 (SD=0.s081) +61 21 12.08 (SD=0."63) 
    with brightness near 18.3m (SD=0.3m)
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