TITLE: GCN CIRCULAR NUMBER: 12369 SUBJECT: GRB 110918A optical observation DATE: 11/09/20 16:36:08 GMT FROM: AAVSO GRB Network at AAVSO Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland), Caisey Harlingten (Harlingten Observatory, San Pedro de Atacama, Chile), Bradley Schaefer (LSU), and Matthew Templeton (AAVSO) report the following follow-up optical observation of the error box of GRB 110918A (Hurley et al., GCN Circ. #12357): A. Oksanen (Hankasalmi Obs., Hankasalmi, Finland) reports an observation of the error box of the intense, long GRB 110918A (Hurley et al., GCNC #12357; Golonetskii, et al., GCNC #12362) using the Harlingten Observatory 0.5-m Planewave telescope with Apogee Alta-U42D9 CCD located in San Pedro de Atacama, Chile. Ten, 60-second unfiltered observations of the field containing the GRB error box were made; the coadded image has a midpoint time of 2011 Sep 20 07:33 UT (JD 2455824.8146), approximately 34 hours post burst. We find the point source detected by Mangano et al. (GCNC #12364) and Tanvir et al. (GCNC #12365) at a preliminary magnitude of R=19.0 measured relative to the nearby USNO-A2.0 star 0600-00854967 (B=18.8,R=17.7). Coadded images of the field are available at the following links: FITS: http://pilvi.dyndns.org/arto/GRB110918A_median.fit JPEG: http://pilvi.dyndns.org/arto/GRB110918A_median.jpg The AAVSO International High Energy Network was made possible through grants from the Charles Curry Foundation and from NASA, and is supported through the AAVSO Endowment.