167 MV LYRAE (NL) Range: 12.5-18.0p Position: 19 07 16.32 +44 01 08.3 (J2000, in .dat file) Magnitude: V=12.507 B-V=-0.050 (in .dat file) ID RA (2000) DEC X Y N V ERR B-V ERR a) Comparison star sequence 1 19 07 02.1 +44 01 51 -153 43 3 12.517 0.024 1.132 0.031 2 19 07 09.2 +43 59 20 -76 -108 3 13.101 0.023 0.556 0.015 3 19 07 09.9 +43 58 44 -70 -144 3 13.873 0.022 1.115 0.023 4 19 07 15.8 +43 59 11 -6 -117 3 14.113 0.023 0.598 0.013 5 19 07 31.5 +44 03 11 164 123 1 14.216 0.005 0.684 0.008 6 19 07 29.6 +43 58 50 143 -138 2 14.469 0.027 0.960 0.006 7 19 07 26.5 +44 02 16 110 68 3 14.704 0.009 1.212 0.031 8 19 07 25.0 +44 00 48 94 -20 3 15.048 0.005 0.483 0.069 9 19 07 25.7 +43 59 32 102 -96 3 15.225 0.016 0.616 0.027 10 19 07 17.8 +44 02 23 16 75 3 15.300 0.016 0.763 0.016 11 19 07 26.2 +44 01 45 107 37 3 15.646 0.020 0.717 0.022 12 19 07 08.2 +44 00 42 -88 -26 3 16.401 0.021 0.925 0.009 13 19 07 21.3 +44 00 44 54 -24 2 16.498 0.022 0.581 0.054 14 19 07 15.1 +44 01 09 -13 1 3 16.673 0.015 0.621 0.019 15 19 07 16.6 +44 01 18 3 10 3 17.143 0.042 0.557 0.069 16 19 07 20.0 +44 01 01 40 -7 3 17.434 0.064 0.726 0.069 17 19 07 15.2 +44 01 26 -12 18 1 17.729 0.051 0.989 0.100 18 19 07 13.5 +44 00 54 -30 -14 3 18.393 0.052 0.761 0.096 b) Wide-colour extension for CCD calibration No wide-colour extension stars are available. Notes: 1. The faint stars 14, 15, 16 and 18 have been remeasured with psf photometry. The main change is that star 15, a very close companion to the variable, is now 0.5 magnitude fainter than in the original .dat file. This original brighter magnitude occurred as a result of contamination from the bright variable, which is now eliminated. 2. MV Lyr is the SW corner star of a quadruple cluster of stars. The other three stars in the group are stars 14, 15 and 17 of this sequence. 3. There are two previous charts for this variable that both contain compsarison stars. They are a revised Preliminary AAVSO chart dated August 1983 and the other a chart dated July 2000 by Reinder Bouma at http://www.shopplaza.nl/astro. This last chart is based on 1997 Henden and Honeycutt data. There is good agreement between all three sequences, except for the few instances detailed below: a) The star shown as 166 on Bouma's chart, located 10 arcsec north of the variable, is actually magnitude 171. b) Star 16 in this sequence, with magnitude 174, is shown completely erroneously on the AAVSO chart with a magnitude of 160. c) The AAVSO star marked as 'var' appears not to be so, and in fact is comparison star 2 in this sequence with a constant magnitiude of 131. Bruce Sumner 7 September 2000