GCN Circular 13986
D. Xu, T. Kruehler, D. Malesani (DARK/NBI), G. Leloudas (OKC Stockholm and DARK/NBI) I. Ilyin (AIP), J. Clasen (NOT), P. Jakobsson (U. Iceland), J. P. U. Fynbo (DARK/NBI) report on behalf of a larger collaboration: We observed the field of GRB 121123A (Helder et al., GCN 13982) using the 2.5m Nordic Optical Telescope (NOT) equipped with StanCam. Observations started at 20:03:43 UT on 2012-11-23 (i.e., 9.972 hr after the BAT trigger) and 5x300s R-band frames were obtained with mid-time of 10.218 hr post-trigger. The afterglow is clearly detected in the stacked image at coordinates R.A.(J2000)= 20:29:16.289 Dec.(J2000)=-11:51:35.87 with R=19.65+/-0.03 mag, calibrated with the #0781-0714632 star (R1=R2=17.17 mag with a scatter of 0.3 mag) in the USNO B1 catalog. We note that our measurement is only modestly fainter than the one reported by Zhao et al. (GCN 13983) at 1.5 hr after the BAT trigger, indicating a shallow decay or an irregular light curve.