TITLE:   GCN CIRCULAR
NUMBER:  29008
SUBJECT: IceCube-201130A: Optical and NIR Imaging Follow-up by Kanata Telescope
DATE:    20/12/09 07:42:41 GMT
FROM:    Mahito Sasada at Hiroshima University  <sasadam@hiroshima-u.ac.jp>

Sasada, M., Nakaoka, T., Akitaya, H. (Hiroshima U.),
Utsumi, Y. (Stanford U./SLAC)

We report our optical and near-infrared imaging observations
for the IceCube high-energy neutrino candidate event,
IceCube-201130A (GCN Circ. 28969).

We selected 11 radio sources from our BROS catalog
(Itoh et al. 2020, ApJ 901, 3) including radio sources 3C 57, and
4FGL J0206.4-1151 (ATel #14235) and imaged each of them
in R and J bands with the Kanata telescope using the HONIR
imaging and spectropolarimeter
(Akitaya et al. 2014, Proc. SPIE 9147, 91474O). We present
magnitudes in the AB system. The upper limits are the 5-sigma
detection limits. Each magnitude is calibrated by nearby stars
listed in PanSTARRS for R, and in 2MASS catalogs for J.

BROS_J0206.4-1150 was also observed by Swift (GCN Circ. 28994).
They reported mild decrease of source activity in X-rays and a
moderate brightening from U to M2 filter on December 2-3 with
respect to December 1. Our observations on 2020-12-01 10:14UT
and 2020-12-02 09:40UT in the R band shown below were not able
to confirm this brightness trend by large photometric error.

BROS_J0201.9-1132 (3C 57) RA:30.488288, Dec:-11.542607
MJD    R    J
59184.41560, 15.89+/-0.04, 16.04+/-0.04
59185.39238, 15.91+/-0.03, 16.09+/-0.04
59186.41061, 15.93+/-0.04, 16.12+/-0.05
59187.54670, 15.98+/-0.09, 16.19+/-0.06
59191.44694, 15.92+/-0.04, 16.08+/-0.03

BROS_J0206.4-1150 (4FGL J0206.4-1151) RA:31.608821, Dec:-11.844354
59184.42646, 19.5+/-0.3, >18.7
59185.40333, 19.8+/-0.3, >18.4
59191.46875, 19.6+/-0.3, >19.2

BROS_J0204.3-1157 RA:31.084787, Dec:-11.960983
59184.43740, 18.4+/-0.2, 17.2+/-0.1
59185.42506, 18.6+/-0.1, 17.3+/-0.1
59186.42147, 18.46+/-0.08, 17.32+/-0.08
59191.45787, 18.41+/-0.08, 17.37+/-0.09

BROS_J0203.7-1250 RA:30.942665, Dec:-12.846279
59184.45914, >19.8, >18.9

BROS_J0200.7-1258 RA:30.193870, Dec:-12.967430
59184.44823, >20.0, >19.0

BROS_J0158.8-0932 RA:29.721666, Dec:-9.539370
59184.48092, >19.7, >18.8

BROS_J0150.5-1212 RA:27.637326, Dec:-12.214537
59184.51353, >18.3, >18.3

BROS_J0155.9-0945 RA:28.988929, Dec:-9.759423
59184.47004, >20.3, >19.4
59185.44682, >20.4, >19.0

BROS_J0200.8-0936 RA:30.215875, Dec:-9.606755
59184.49623, >18.5, >17.5

BROS_J0202.0-1451 RA:30.523600, Dec:-14.863539
59184.52442, 17.9+/-0.2, 17.0+/-0.1
59191.47962, 17.8+/-0.1, 16.91+/-0.07

BROS_J0202.8-0930 RA:30.713050, Dec:-9.514563
59184.50265, >19.9, >19.0