TITLE:   GCN CIRCULAR
NUMBER:  21723
SUBJECT: LIGO/Virgo G299232: Transient near NGC 1343 has a somewhat blue r-i color
DATE:    17/08/27 16:45:39 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

We obtained r, i, and z-band images of MASTER OTJ033744.97+723159.0 near
NGC 1343 (Lipunov et al. GCN 21719, 21720), a candidate counterpart of
G299232/PGW170826 (Siellez et al. GCN 21693). The data were taken with
SQUEAN instrument on the McDonald Observatory’s 2.1m telescope at
2017-08-27, 10:57 (UT). Before Galactic extinction correction, it has r =
16.67 +- 0.03 and i = 16.71 +- 0.03 (AB mag), with r-i color of r –i ~
-0.04 mag. However, after Galactic extinction correction, we get r= 15.89
and i = 16.13 and r-i = -0.24 mag, a rather blue color in comparison to
G298048 shortly after its discovery (Nicholl et al. GCN 21541).