TITLE: GCN CIRCULAR NUMBER: 6353 SUBJECT: LT monitoring of GRB070412 DATE: 07/04/27 11:54:45 GMT FROM: Evert Rol at U.Leicester E. Rol, N. Tanvir (U. of Leicester), R. Smith (Liverpool JMU), report for a larger collaboration: We have observed the field of GRB070412 (Romano, GCN Circ. 6273) in r' and i' bands with the 2m Liverpool Telescope at several epochs. At the position of the X-ray afterglow (Romano, GCN Circ. 6282), we do not detect any new sources. Our photometry is calibrated relative to the SDSS (Adelman-McCarthy et al., 2007 ApJS in press), and our limiting magnitudes at the observed epochs are as follows: UT start days post T0 exptime filter lim. mag (2007) (mid-epoch) (sec) (5-sigma) 04-12T03:13:03 0.077 600 r' 22.5 04-12T04:07:56 0.115 600 i' 21.9 04-12T04:31:59 0.132 600 r' 22.4 04-12T21:33:59 0.849 1800 r' 22.6 04-13T01:48:36 1.026 1350 i' 21.6 04-13T03:32:13 1.098 1800 r' 23.4 04-13T04:06:36 1.122 900 i' 20.7 04-15T01:11:04 3.000 1800 r' 23.7 04-15T01:50:38 3.012 1800 i' 23.2 04-25T21:34:13 13.85 1800 r' 22.3 * 04-25T22:08:19 13.87 1800 i' 22.2 * * observations are affected by contamination from the nearby moon Since the upper limits indicate no apparent supernova at the X-ray position, the GRB position is either a chance coincidence with the nearby bright galaxy (CGCG 215-024; see also Ofek, GCN Circ. 6275), or belongs to the newly suggested class of long-duration GRBs that show no associated supernovae (Fynbo et al. 2006, Nature 444, 1047; Della Valle et al. 2006, Nature 444, 1050; Gal-Yam et al. 2006, Nature 444, 1053). For comparison, the expected magnitudes at 13.9 days for a SN1998bw-like supernova at the redshift of the galaxy (z=0.0307), are r' = 17.3 and i' = 17.6.