TITLE: GCN CIRCULAR NUMBER: 957 SUBJECT: GRB 010220, simultaneous optical observations DATE: 01/02/21 22:56:04 GMT FROM: Alberto Castro-Tirado at LAEFF-INTA GRB 010220, simultaneous optical observations by BOOTES-1 --------------------------------------------------------- Alberto Castro-Tirado, IAA-CSIC (Granada) and LAEFF-INTA (Madrid) José María Castro Cerón, ROA (San Fernando) Tomás Mateo, CEDEA-INTA (Arenosillo) René Hudec and Jan Soldán, ASU (Ondrejov) Petr Páta and Martin Bernas, CVUT-FEL (Prague) José Ángel Berná, Univ. de Alicante (Alicante) Javier Gorosabel, DSRI (Copenhagen) Benito de la Morena, CEDEA-INTA (Arenosillo) José Torres, DEC-INTA (Madrid) on behalf of the BOOTES-1 Team report: "We have obtained about 30 images of a field containing the BSAX/WFC error box for the 150 s long GRB 010220 (Piro et al. GCN 953, Manzo et al. GCN 956) with the ultra wide-field CCD of BOOTES-1 during the time interval Feb 20.93-Feb 20.97 UT (+/- 0.5 h around the GRB occurrence). The exposures, with integration time of 60 s, cover a field of 40 x 28 deg� and reach a limiting magnitude of about R = 10. None of the frames, including the one ending at 22:51:15 UT, i.e. covering the first 8 s of the event, reveals an optical transient within the BSAX/WFC error circle. The next frame started at 22:52:15 UT and covers the time interval t_0 + 68 s to t_0 + 128 s. We notice that the galactic nebula IC 1805 lies along the line of sight of the GRB, at a galactic latitude of b = +1.38 deg, i.e. the extinction is high (A_v = 3.3 mag). Images and additional information can be found at http://www.LAEFF.ESA.Es/~ajct/GRBs/GRB010220/ . This message can be cited." [GCN OPS NOTE(12Mar01): Two typos have been corrected. The phrase "GCN 957) with the" has been changed to "GCN 956) with the". And "Feb 21.93-Feb 21.97 UT" has been changed to "Feb 20.93-Feb 20.97 UT".]