GCN Circular 252

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.

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