[vsnet 1791] CH UMa sequence

["Robert J. Modic" <rjmodic@stratos.net>]

     Below is a sequence of comparison stars I've extracted from Arne
Henden's .dat file for the CH UMa field.  Five stars from the Tycho
catalog are listed as well.  Stars were selected based on their
proximity to the variable, similar B-V as the variable and previous use
as comparison stars by the AAVSO.  CH UMa has a B-V of 0.5 in quiescence
and probably about 0.0 in outburst.  The AAVSO Pv magnitudes are from
the Preliminary "d" and "e" charts dated 4/1993.

Regards,

Robert J. Modic (MRV)
AAVSO

--------------------

Variable: CH UMa (UG)               Range: 10.7v-15.9v

Position: 10 07 00.81, +67 32 47.7 (J2000, from .dat file)


 ID   Offsets(")   RA  (J2000)  DEC    n    V      B-V      Errors     Remarks/
        x    y                                                         AAVSO Mag
--------------------------------------------------------------------------------
  1 -1171  285  10 03 36.3  +67 37 32      9.60   1.533  0.025  0.075  1  / 9.4
  2  1118 -459  10 10 16.1  +67 25 09     10.05   0.793  0.032  0.045  1  /10.0
  3  1271  404  10 10 42.7  +67 39 32     10.26   0.671  0.037  0.048  1  /10.3
  4   250 1019  10 07 44.5  +67 49 47     10.73   1.120  0.066  0.131  1  /10.6
  5   -27 -749  10 06 56.0  +67 20 19     10.93   0.998  0.089  0.157  1  /11.0
  6  -578  643  10 05 20.0  +67 43 30     11.17   0.804  0.113  0.171  1,2/11.5
  7   430  371  10 08 15.9  +67 38 59  3  12.109  0.486  0.005  0.024      12.0
  8  -309 -200  10 06 06.9  +67 29 27  2  12.781  0.629  0.000  0.020      12.7W
  9   394  183  10 08 09.6  +67 35 50  3  12.844  0.966  0.005  0.022      12.7E
 10  -125 -496  10 06 39.0  +67 24 32  2  13.243  0.576  0.006  0.031      13.2
 11   423  322  10 08 14.7  +67 38 09  3  13.299  0.496  0.005  0.023      13.1E
 12     5 -317  10 07 01.6  +67 27 31  2  14.177  0.757  0.006  0.023      13.7
 13   221 -226  10 07 39.3  +67 29 02  2  14.318  0.712  0.000  0.018      14.0
 14   -40  401  10 06 53.8  +67 39 29  3  14.821  0.883  0.000  0.023
 15   -99  348  10 06 43.6  +67 38 36  3  14.970  0.510  0.014  0.045
 16    41  -86  10 07 07.9  +67 31 21  5  15.261  0.628  0.012  0.042      15.1
 17     3 -256  10 07 01.3  +67 28 31  2  15.666  0.502  0.006  0.016      15.3
 18   486  -19  10 08 25.6  +67 32 29  3  15.970  0.805  0.014  0.031

Note: x and y offsets are positive to the east and north respectively.

Remarks:

1) Tycho Catalog; errors are for VT and B-V, respectively

2) The Tycho V magnitude appears to be 0.2 - 0.3 mag too bright visually, so
   the AAVSO Pv mag for this star is probably the better one.

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