TITLE: GCN GRB OBSERVATION REPORT NUMBER: 252 SUBJECT: GRB 990123: BVRI standards in the field DATE: 99/02/08 06:29:35 GMT FROM: Ram Sagar at UPSO Nilakshi, R.K.S. Yadav, V. Mohan, A.K. Pandey and R.Sagar of U.P. State Observatory, Manora Peak, Nainital, India report: We have determined the Johnson BV and Cousins RI CCD magnitudes of 18 objects in the field of GRB 990123 with the 104-cm Sampurnanand telescope of the U.P. State Observatory, Manora Peak, Nainital under good photometric sky conditions. The photometric standards present in the field of open star cluster M67 have been used for calibration. The BVRI standard magnitudes of these objects alongwith RA, DEC (J2000) and DAOPHOT photometric errors prefixed with S are given below. ------------------------------------------------------------------------ Object RA Dec h m s o ' '' V SV B-V S(B-V) V-R S(V-R) V-I S(V-I) ------------------------------------------------------------------------- 1 15 25 27.0 44 46 23.2 14.84 0.00 0.57 0.00 0.32 0.00 0.58 0.00 2 15 25 36.5 44 44 37.6 15.47 0.00 0.63 0.01 0.36 0.01 0.67 0.01 3 15 25 11.8 44 46 2.1 15.96 0.00 0.64 0.00 0.41 0.01 0.78 0.01 4 15 25 21.1 44 46 46.9 16.28 0.00 0.67 0.00 0.39 0.00 0.71 0.01 5 15 25 38.6 44 43 20.3 16.72 0.00 0.60 0.01 0.32 0.01 0.63 0.01 6 15 25 21.7 44 46 52.7 16.80 0.00 1.35 0.01 0.82 0.00 1.54 0.01 7 15 25 38.8 44 44 30.1 17.65 0.06 1.29 0.07 0.83 0.08 1.34 0.08 8 15 25 17.9 44 46 29.5 18.10 0.01 1.13 0.01 0.66 0.01 1.17 0.01 9 15 25 39.1 44 44 46.1 18.48 0.05 1.32 0.07 0.67 0.08 1.25 0.07 10 15 25 19.6 44 47 53.0 18.66 0.01 1.45 0.02 0.86 0.01 1.64 0.01 11 15 25 19.3 44 45 58.1 18.72 0.01 0.47 0.01 -------- 0.53 0.02 12 15 25 15.6 44 45 5.6 18.96 0.03 0.87 0.04 0.53 0.04 0.98 0.05 13 15 25 32.7 44 44 29.9 19.01 0.01 0.53 0.02 0.37 0.01 0.69 0.02 14 15 25 25.3 44 45 24.7 19.16 0.05 1.36 0.07 0.70 0.07 1.23 0.07 15 15 25 16.4 44 47 28.4 19.65 0.02 1.39 0.04 0.88 0.02 1.71 0.03 16 15 25 13.8 44 44 50.1 19.87 0.03 0.43 0.04 0.27 0.03 0.34 0.06 17 15 25 26.6 44 43 55.3 20.14 0.03 1.06 0.06 0.80 0.03 1.23 0.04 18 15 25 27.5 44 44 43.6 20.31 0.03 0.48 0.05 0.40 0.03 0.43 0.09 -------------------------------------------------------------------- At the Web site http://www.rri.res.in/grb990123/ the manuscript dealing with the above data are available. The title of the paper is " BVRI CCD photometric standards in the field of GRB 990123". It has been accepted for publication in the Bull. Astron. Soc. India. This message may be cited.