TITLE: GCN CIRCULAR NUMBER: 18771 SUBJECT: LIGO/Virgo G211117: SkyMapper observations and transient candidate DATE: 15/12/30 13:44:59 GMT FROM: Fang Yuan at ANU Fang Yuan, Christian Wolf, Brian Schmidt (ANU) We report tiled observations of LIGO/Virgo G211117 using the 1.3m SkyMapper telescope located at Siding Spring Observatory in Australia. Starting UTC 2015-12-29T17:09:41 (3.56 days after the trigger), SkyMapper observed 20 fields, covering a sky area of about 110 sq. deg, with 2x30s i-band exposures. Footprint of the observations has been uploaded to GraceDB. These fields are selected based on weight calculated from the GW skymap, the GW Galaxy Catalogue (augmented by 2MASS Ks photometry) and existence of SkyMapper pre-trigger observations. Using the latest GW skymap, we estimate a chance of 9% that these fields contain the true location of the source. Images were taken during twilight with limiting mag of about 18.6 in i-band. Image subtraction have been performed against SkyMapper templates taken from May to July 2015 as part of the Southern Sky Survey. One optical transient candidate has been detected with the following details: ID, RA, DEC, mag, filter, JD, Apparent Host (redshift) ------------------------------------------------------------------------------------------ SMTJ13331687-1607330, 13:33:16.87, -16:07:33.0, 18.0+/-0.1, i, 2457386.2387, MCG -03-35-004 (0.020)