TITLE: GCN CIRCULAR NUMBER: 6281 SUBJECT: GRB 070412: further NOT observations DATE: 07/04/12 09:01:56 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center Daniele Malesani (DARK/NBI) and Helene Uthas (NOT) report on behalf of a larger collaboration: We observed again the field of GRB 070412 (Romano et al., GCN 6273) with the NOT. Observations were carried out at two epochs, ~0.9 and ~3.5 hr after the GRB. R- and I-band images were secured at each epoch. Inside the XRT error circle, we do not detect the sources reported by Jelinek et al. (GCN 6279) and Berger (GCN 6280). The 3-sigma limiting magnitudes are: t-t0 I limit R limit -------------------------- 0.9 hr 22.9 24.0 3.5 hr 23.1 24.2 These numbers were computed assuming R = 17.38 and I = 17.17 for the USNO star at RA = 12:06:02.17, Dec = +40:09:01.4. We note that the magnitude reported by Berger (GCN 6280) is fainter than our limits. Our early measurement implies a decay shallower than ~t^-0.7. The object reported by Malesani & Uthas (GCN 6276) is detected only in the first R-band image, thus leaving open the possibility that this source was fading. However, we caution about the low significance of this detection.