TITLE: GCN GRB OBSERVATION REPORT NUMBER: 563 SUBJECT: GRB 000115 Optical observations DATE: 00/02/18 20:12:14 GMT FROM: Javier Gorosabel at LAEFF-INTA, Madrid J. Gorosabel (DSRI, Copenhagen, Denmark) F. Vrba, A. Henden (U. S. Naval Observatory, Flagstaff, USA) V. Mohan, A.K. Pandey, R. Sagar, S.B. Pandey (UPSO, Nainital, India) P. Kilmartin (University of Canterbury, New Zealand) I. Bond, N. Rattenbury, P. Yock (University of Auckland, New Zealand) A.J. Castro-Tirado (LAEFF-INTA, Madrid and IAA-CSIC, Granada, Spain) report on behalf of a larger European collaboration: "We have obtained optical images of the RXTE/IPN error box of GRB 000115 (GCN 519, GCN 520) with the UPSO 1.04-m Sampurnanand telescope, the USNO Flagstaff Station 1.0-m telescope and the 0.61-m Mount John University Observatory (MJUO) telescope between Jan 16.275 UT and Jan 19.764 UT. The observations are summarized in the following table: Date Telescope Seeing(") Exp. Filter Lim. Mag. ------------------------------------------------------------------------ Jan 16.275-16.357 1.00-USNO 2.7 5400 R^ 22.1 Jan 17.701-17.765 1.04-UPSO 2.6 4200 I 21.7 Jan 17.906-17.950 0.61-MJUO 3.1 900 (R+I)* I~20 Jan 18.781-18.899 1.04-UPSO 3.1 3000 I 21.2 Jan 19.697-19.764 1.04-UPSO 2.4 4200 I 22.0 ------------------------------------------------------------------------ ^ The image does not completely cover the RXTE/IPN error box, missing the southern part (~20%) of it. * Observations performed through a broad-band filter (R + I bandpass). ------------------------------------------------------------------------ Photometry of these data does not reveal reliable variable sources in the error box, being any variability less than I=0.25 and R=0.20 mag for objects with I < 21 and R < 21. The USNO R-band co-added image has been compared to the one taken with the 1.54-m Danish telescope on Jan 21.344-21.382 UT (GCN 524). The zero points have been determined based on the standard stars given by A. Henden (GCN 558)." This message may be cited.