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).