TITLE:   GCN CIRCULAR
NUMBER:  21738
SUBJECT: LIGO/Virgo G299232: Continued observation of the transient near NGC 1343
DATE:    17/08/29 02:11:20 GMT
FROM:    Myungshin Im at Seoul National U  <myungshin.im@gmail.com>

M. Im, C. Choi, G. Lim, J. Kim, H. M. Lee (SNU), M. J. Kim, H. J. Lee
(KASI) on behalf of the KU collaboration

At 2017-08-28 11:00 (UT), we continued the observation of MASTER
OTJ033744.97+723159.0 near NGC 1343 (Lipunov et al. GCN 21719, 21720) with
the SQUEAN instrument on the McDonald Observatory���s 2.1m telescope. AB
magnitudes before and after the Galactic extinction correction are given
below.

Before | Extinction | After

g 16.97  1.125  15.85

r  16.49   0.778   15.71

i  16.56    0.578  15.98

The object has brightened by ~0.2 mag in one day and stayed blue in r-i but
has a redder color in g-r (c.f. Lipunov et al. GCN 21736). The brightening
is consistent with the report that this is a type IIb SN before maximum
(Jonker et al. GCN 21737).