111  CG CANIS MAJORIS   (UG)   Range: 13.7-<16.4V
     Position:   07 04 05.23 -23 45 34.2 (J2000, Henden, single night)
     Magnitude:  unknown

ID     RA (2000)    DEC       X    Y   N    V      ERR     B-V    ERR   
 
a) Comparison star sequence

1   07 03 49.6  -23 49 33  -214 -239  3  11.341  0.062   0.879  0.054   
2   07 04 13.4  -23 48 06   113 -152  3  11.934  0.008   1.499  0.013   
3   07 04 03.1  -23 47 35   -28 -121  3  12.841  0.077   0.245  0.008   
4   07 04 00.3  -23 41 16   -67  258  4  13.147  0.015   0.686  0.010   
5   07 04 03.9  -23 44 36   -18   58  3  13.631  0.011   0.497  0.009   
6   07 03 52.1  -23 46 00  -180  -26  3  13.910  0.016   0.655  0.010   
7   07 04 11.8  -23 46 09    91  -35  3  14.246  0.017   0.450  0.003   
8   07 04 04.9  -23 44 59    -4   35  3  14.449  0.008   1.066  0.015   
9   07 04 04.0  -23 42 57   -16  157  3  14.799  0.016   0.661  0.009   
10  07 04 14.8  -23 44 50   132   44  3  15.067  0.012   0.659  0.008   
11  07 04 00.8  -23 44 08   -60   86  3  15.666  0.018   0.159  0.008   
12  07 04 00.6  -23 46 03   -63  -29  3  16.011  0.026   0.628  0.015   
13  07 04 05.0  -23 45 35    -2   -1  2  16.447  0.012   0.516  0.014   
14  07 04 01.3  -23 45 22   -54   12  3  16.550  0.011   1.386  0.020   
15  07 04 05.6  -23 46 00     5  -26  3  17.235  0.038   0.375  0.029   


b) Wide-colour extension for CCD calibration

    07 04 30.3  -23 49 53   345 -259  2  12.977  0.012   0.055  0.008   
    07 03 48.5  -23 44 03  -229   91  3  13.981  0.009   1.564  0.014   

   
Notes:

1. CG CMa has a very close companion of V=16.4 located only 2.9 
arcsec west of the variable. This companion is star #13 in the above 
sequence. Great care will be needed not to confuse this companion 
with CG CMa when the variable is faint. 

2. The photometry and astrometry of the variable and its companion 
were obtained from psf fitting by Arne Henden on an image obtained 
on a night of good seeing when the variable and the companion were 
both of about equal magnitude. This technique eliminates mutual
contamination of each object. On that night, as the variable was 
fading, it was measured with V=16.543+/-0.013 and B-V=0.034+/-0.011.

3. The quiescent magnitude of CG CMa is unknown, but it is certainly 
much fainter than its companion.

4. There is a bright star just to the southwest of star #1. This 
bright star has a reliable Tycho-2 magnitude of V=10.07+/-0.03.


Bruce Sumner
14 April 1999
Revised 3 January 2001