TITLE: GCN GRB OBSERVATION REPORT NUMBER: 572 SUBJECT: GRB000301c, near-infrared observations DATE: 00/03/03 15:44:25 GMT FROM: Sylvio Klose at TLS Tautenburg B. Stecklum, S. Klose (Thueringer Landessternwarte Tautenburg), O. Fischer (Universitaets-Sternwarte Jena), C. Bailer-Jones, U. Thiele, A. Aguirre (Max-Planck-Institut fuer Astronomie, Heidelberg), F. J. Vrba, A. A. Henden, C. B. Luginbuhl, B. Canzian, S. E. Levine, H. H. Guetter, J. A. Munn (U.S. Naval Observatory, Flagstaff), D. H. Hartmann (Clemson University, Clemson), A. Castro-Tirado (LAEFF-INTA, Madrid, and IAA-CSIC, Granada), J. Greiner (AIP Potsdam), and J. Gorosabel (LAEFF-INTA, Madrid, and University of Amsterdam) report: The error box of the burst GRB 000301c reported by Smith et al. (GCN #568) was imaged with the Calar Alto 3.5-m telescope on March 3, 4:41 UT - 5:38 UT using the near-infrared camera Omega Cass. The frames were taken in the course of a project whose goal is to measure the degree of linear polarization of GRB afterglows. The limiting magnitude of the K'-band image is about K'=19 after adding all images taken at different position angles of the wire-grid polarizer. The potential optical transient reported by Fynbo et al. (GCN #570) is clearly detected. Based on the assumption that the B-R colour index of the star USNO 125_07686794 is representative for its spectral type, a preliminary estimate of the K'-band magnitude of the potential afterglow of 17.4 was derived. The image is posted on the Tautenburg Web page at http://www.tls-tautenburg.de/research/grb000301c.html. This message is quotable.