TITLE:   GCN CIRCULAR
NUMBER:  21778
SUBJECT: LIGO/Virgo G298048: Continued Gemini South observations
DATE:    17/08/31 18:28:50 GMT
FROM:    Eleonora Troja at GSFC/Swift  <nora.gsfc@gmail.com>

E. Troja (UMD/GSFC), N. Butler (ASU), A. Watson (UNAM), S. Covino (INAF),
W. H. Lee (UNAM), J. Becerra-Gonzalez (UMD/GSFC), A. Lien (UMBC),
T. Sakamoto (AGU), and P. D'Avanzo (INAF):

We continued optical and near-infrared observations of SSS17a (Coulter et
al., LVC GCN 21529). The source appears substantially fainter than
in our previous observations ( Troja et al., LVC GCN 21682),
consistent with the rapid NIR fading reported by Chornock & Berger
(LVC GCN 21684).  However, over the course of the last three nights,
the NIR countepart appears to have flattened inthe Ks-band at
a level of ~17.7 mag.

We thank the entire Gemini-South staff and the director, Laura Ferrarese,
for their support of these observations.

[GCN OPS NOTE(31aug17): Per author's request, the middle sentence 
as added to the first paragraph.]