TITLE:   GCN CIRCULAR
NUMBER:  20877
SUBJECT: LIGO/Virgo G277583:  ATLAS17cck - a fast declining transient 
DATE:    17/03/15 22:48:00 GMT
FROM:    S. J. Smartt at Queens U Belfast  <s.smartt@qub.ac.uk>

J. Tonry, L. Denneau, A. Heinze, B. Stalder, H. Weiland (IfA),
C. W. Stubbs (Harvard), K. W. Smith, S. J. Smartt, D. R. Young
E. Kankare, (QUB), A. Rest (STScI), K. C. Chambers (IfA), M. Coughlin
(Harvard), M. E. Huber (IfA), D. E. Wright (QUB), H. Flewelling,
E. A. Magnier, A. S. B. Schultz, C. Waters, R. J. Wainscoat (IfA),
T. W Chen (MPE)


We observed the skymap of G277583 on MJD=57826 and 57827 with ATLAS
(see Tonry et al. GCN 20382) in the orange filter (a composite
r+i). 

Full details will follow soon, but we immediately draw attention to
the following fast declining transient. We plan further photometry
with Pan-STARRS1, but a spectrum as a soon as possible would 
be desirable.

The decline rate is 0.54 mag/hr

ATLAS17cck  07:44:50.33 +24:45:54.8  (116.20972 +24.76524)

Lightcurve : 
   Mag  err   MJD
 >18.97          57826.4410705
  15.78 0.03   57827.4286248
  15.81 0.03   57827.4315352
  15.87 0.03   57827.434911
  15.99 0.03   57827.4353887
  15.96 0.04   57827.4428893
  16.19 0.04   57827.4599793

We find no previous catalogued source at this position, neither
galaxy or star.