TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1923 SUBJECT: GRB 030226, further optical/NIR imaging DATE: 03/03/05 11:33:55 GMT FROM: Sylvio Klose at TLS Tautenburg S. Klose, B. Stecklum, A. Zeh (all TLS Tautenburg), J. Greiner (MPE Garching), A. A. Henden (USRA/USNO, Flagstaff), on behalf of the GRACE collaboration report: We have continued our efforts of a multi-color imaging of the optical/ near-infrared afterglow of GRB 030226 with the ESO VLT telescopes at Paranal. Observations performed 4 days after the burst clearly show a source at the position of the optical transient (OT; Price et al., GCN 1880). This source is detected in all photometric bands. Based on an aperture photometry, a comparison of the pre-break optical/near-infrared colors of the optical transient with its post-break colors reveals no apparent differences. Although this result is still preliminary and small differences might still be detectable based on a more accurate PSF photometry, we conclude: To a good approximation, the break in the light curve was achromatic and at the time of the VLT observations the OT's light was still dominated by the afterglow. A first inspection of the data obtained 4 days after the burst seemed to confirm a further steepening of the light curve in all bands some days after the burst (Kulkarni et al., GCN 1911). However, our data do not rule out the possibility that the reported steepening was a temporary fluctuation between t ~2 and 3...4 days after the burst. In particular, very recent VLT/FORS data show that the overall brightness evolution of the OT still follows the predicted light curve (Zeh et al., GCN 1898) with alpha_2 ~2 (assuming that we do not begin to see the host galaxy). We are grateful for the assistence of the staff at Paranal.