159 V452 CASSIOPEIAE (UGSU) Range: 14.5-18.7V Position: 00 52 18.03 +53 51 49.9 (J2000, Henden astrometry) Magnitude: V=18.741 B-V=0.299 (Henden, singel night) ID RA (2000) DEC X Y N V ERR B-V ERR a) Comparison star sequence 1 00 52 04.9 +53 50 59 -116 -51 4 12.035 0.120 0.667 0.025 2 00 52 21.6 +53 52 31 32 41 3 12.410 0.072 0.127 0.048 3 00 52 19.6 +53 48 15 15 -215 3 12.644 0.100 1.146 0.100 4 00 52 51.5 +53 50 55 296 -55 3 13.346 0.005 0.471 0.006 5 00 52 20.6 +53 50 56 23 -55 3 13.640 0.019 1.263 0.030 6 00 52 41.5 +53 49 05 208 -165 3 14.162 0.009 0.356 0.004 7 00 52 07.7 +53 49 26 -91 -144 3 14.435 0.005 0.774 0.005 8 00 52 33.0 +53 50 25 132 -85 3 14.582 0.005 0.629 0.009 9 00 52 04.7 +53 50 27 -118 -84 3 14.999 0.011 0.825 0.002 10 00 52 26.9 +53 52 43 79 53 3 15.420 0.006 0.638 0.011 11 00 52 14.7 +53 52 03 -29 12 3 15.586 0.009 0.685 0.010 12 00 52 18.3 +53 51 44 3 -7 3 15.799 0.000 1.324 0.007 13 00 52 20.5 +53 51 48 22 -2 3 16.587 0.018 0.644 0.014 14 00 52 18.5 +53 52 04 4 14 3 17.192 0.011 0.858 0.006 15 00 52 15.1 +53 51 46 -25 -4 3 17.735 0.017 0.812 0.017 16 00 52 19.4 +53 51 19 12 -31 3 18.856 0.017 0.711 0.143 b) Wide-colour extension for CCD calibration 00 52 02.9 +53 56 24 -134 274 3 12.164 0.062 0.178 0.008 00 52 50.8 +53 48 02 290 -228 3 14.658 0.028 1.527 0.026 00 52 57.2 +53 58 02 346 372 3 13.725 0.010 1.544 0.004 Notes: 1. Stars #1, #2 and #3 are saturated and they should be used for guidance only until accurate magnitudes are determined. 2. There is a bright star located only 100 arcsec south of V452 Cas that has reliable Tycho-2 photometry: V=9.66 +/-0.02. Another bright Tycho-2 star is located at 00h 52m 47.0s +53d 54' 13" and has a reliable magnitude of V=9.40 +/-0.02. Additionally there are several other bright stars in this field. 3. There is a close red companion located 7" SSE of the variable, star #12 in this sequence, with a magnitude of V=15.798. This star has been incorrectly identified as the variable in the past (Downes and Shara, 1993). A correct identification chart is given in Downes, Webbink and Shara (1997). Extreme care is needed to correctly identify the variable as the fainter northern component of this double when the variable is at minimum. 4. Superhumps with a period of 0.0882d were found by Vanmunster in 1999 show this to be a SU UMa-type dwarf nova. Varies at minimum between about V=18.2 and V=18.7. Bruce Sumner 31 July 2000 Revised 20 September 2000 Revised 1 February 2001