TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4913 SUBJECT: GRB 060323: Tautenburg OT candidate retraction DATE: 06/03/24 03:57:00 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann (TLS Tautenburg), S. Covino (INAF/OABr) and D. Malesani (SISSA) report: We concur that the candidate afterglow of GRB 060323 reported by Kann & Stecklum (GCN 4909) is faintly visible in the SDSS. The astrometry reported by Kann & Stecklum (with errors of 0."7) is correct, but the object was misidentified. The afterglow candidate reported by Covino et al. (GCN 4911) is visible on the TLS Ic and Rc image and possibly on the V band image. Photometry of the OT candidate by Covino et al. using the comparison star given by Kann & Stecklum shows marginal evidence for fading, but the low S/N makes it difficult to assess this with certainty. Assuming the magnitude of 23.1 at 0.37 days after the GRB to be correct, this is one of the faintest afterglows ever discovered. The extinction along the line of sight is negligible (E(B-V)=0.015, Schlegel et al., 1998) and there are no indications of excess hydrogen column density in the X-ray afterglow (Vetere et al., GCN 4910). This seems to exclude a large extinction within the GRB host galaxy. The afterglow is fainter at this epoch than all afterglows in the sample of Kann, Klose & Zeh (ApJ, in press, astro-ph/0512575), and also fainter than other faint OTs not in the sample. Another explanation for the faintness may be that this is a high-redshift event, even though the BAT analysis (Parsons et al., GCN 4912) shows no signs of extended low-level emission often seen in high-redshift events (e.g., GRB 050904). We highly encourage NIR observations of the Covino et al. afterglow candidate to determine the colors and look for a possible Lyman dropout. Spectroscopy is also encouraged, but very large facilities will be needed. This message may be cited.