TITLE: GCN GRB OBSERVATION REPORT NUMBER: 173 SUBJECT: GRB 981226 - Infrared Observations DATE: 98/12/28 03:58:18 GMT FROM: Alberto Castro-Tirado at LAEFF-INTA GRB 981226 A. J. Castro-Tirado and J. Gorosabel, Laboratorio de Astrofisica Espacial y Fisica Fundamental, Madrid N. Drory and B. Konig, Universitaetssternwarte, Munich V. Motta, Univ. de la Republica, Montevideo N. Gonzalez, Instituto de Astrofisica de Canarias, Tenerife J. Aceituno, Calar Alto Observatory, Almeria J. Greiner, Astrophysikalisches Institut, Potsdam F. Frontera and E. Palazzi, Istituto di Astrofisica Spaziale, Frascati (on behalf of the BeppoSAX team) We have obtained J-band images at the 3.5-m telescope (equipped with Omega) at the German-Spanish Calar Alto Observatory, on Dec 26.76 (300-s) and Dec 27.76 (1700-s). Within the BeppoSAX position for the X-ray source in the GRB 981226 error box (di Ciola et al. IAU Circ. 7074), we find a variable object with J = 19.4 (Dec 26.76) and J = 20.5 (Dec 27.76). These values are still preliminary. The position is RA(2000) = 23 29 35.0, Dec(2000) = -23 55 42 (+/- 3"). The object reported by Galama et al. (GCN Circ. 172) does not exhibit any variability larger than 0.1 mag. Further observations are encouraged in order to confirm whether the above-mentioned object is the counterpart to GRB 981226. A finding chart can be retrieved via anonymous ftp to laeff.esa.es (under /pub/users/ajct/grb981226). This report is quotable in any publication.