109  RZ LEONIS   (UGSU)   Range: 12.0-18.6V
     Position:   11 37 22.27  +01 48 58.7 (J2000, from .dat file)
     Magnitude:  V=18.608  B-V=0.060      (.dat file, single night)

ID     RA  (2000)   DEC       X    Y   N    V      ERR     B-V    ERR     

a) Comparison star sequence

1    11 37 29.2  +01 53 45   103  286  4  12.242  0.014   0.476  0.011   
2    11 37 13.2  +01 47 57  -136  -62  4  12.589  0.014   0.952  0.010   
3    11 37 37.8  +01 53 22   233  263  4  13.170  0.009   0.785  0.005   
4    11 37 06.3  +01 44 28  -239 -271  4  13.504  0.009   0.619  0.007   
5    11 37 26.4  +01 48 44    62  -15  4  14.086  0.014   0.710  0.009   
6    11 37 43.0  +01 47 42   310  -77  4  14.666  0.008   0.653  0.011   
7    11 37 32.5  +01 47 22   153  -97  4  15.220  0.024   0.705  0.010   
8    11 37 39.6  +01 45 43   259 -196  4  16.025  0.009   1.137  0.012   
9    11 37 30.5  +01 48 38   122  -21  4  16.546  0.018   0.728  0.004   
10   11 37 24.9  +01 47 06    40 -113  4  17.840  0.026   0.731  0.029   


b) Wide-colour extension for CCD calibration

None available.


Notes:

1. There are some AAVSO magnitudes, on chart 1132+02e dated August 1992.
Misselt also measured two stars.

                 ID    Henden    AAVSO     Misselt
                         V         V       V     B-V    
                  2    12.590    12.9    12.705 0.915
                  3    13.169    13.4
                  4    13.502    13.6
                  5    14.087    14.0    14.201 0.687

2. A revised AAVSO chart was issued in December 2000 and includes 
the new sequence determined here.

3. There is a bright star on the northern edge of this field at 
11h 37m 20.0s +01d 56' 15" with a reliable Tycho-2 magnitude of
V=9.19+/-0.02.

4. Originally classified as a recurrent nova, this variable star 
was seen to exhibit superhumps in December 2000, leading to a 
reclassification as a SU UMa-type variable star (Vanmunster 2000,
vsnet-alert 5446). 

5.Minimum appears constant at V=18.6.


Bruce Sumner
14 April 1999
Revised 20 January 2001