COMMISSION 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3847 Konkoly Observatory Budapest 24 February 1993 HU ISSN 0374 - 0676 W Cru - A PHASE DIAGRAM Phase diagram for W Cru based on observations obtained from 1985 to 1987 at the Nigel Observatory, was published by Pazzi (1989). What is presented here is an update which includes all observations of this peculiar eclipsing binary from 1985 to 1991 (JD 2446168 to JD 2448466). The series of photoelectric observations were started following a request for observation by Plavec (1984). Particular attention was paid to the secondary minimum, the reason for this being that a certain amount of data for the primary minimum has already been published by various investigators: Knipe (1972), Marino et al. (1984), Menzies and Spencer Jones (1984), Marino et al. (1988), Kviz and Rufener (1988) and Kohoutek (1988). [FIGURE 1] Figure 1. V-C magnitudes in B and V filters against phase for W Cru. Phase is computed from E=2440731.6, P=198.53. Table I Variable-Comparison "V" magnitude reduced to the UBV system, used to plot Figure 1. JD HEL.CORR. F V-C JD HEL.CORR. F V-C 2446168.3081 0.0021 V -0.1030 2447635.3181 0.0018 V -0.2748 2446172.3009 0.0019 V -0.1036 2447649.2891 0.0010 V -0.2661 2446180.3256 0.0015 V -0.0369 2447656.2741 0.0006 V -0.2274 2446194.2813 0.0007 V -0.0009 2447659.2902 0.0005 V -0.1949 2446202.2384 0.0002 V -0.1137 2447669.3152 -0.0001 V 0.1329 2446229.2850 -0.0013 V -0.3246 2447672.3077 -0.0003 V 0.3054 2446236.3207 -0.0017 V -0.3222 2447677.3180 -0.0006 V 0.9472 2446262.2786 -0.0029 V -0.1114 2447679.3052 -0.0007 V 0.4933 2446265.2325 -0.0030 V -0.0702 2447683.2837 -0.0010 V 0.5453 2446269.2259 -0.0031 V -0.0596 2447686.2868 -0.0011 V 0.5150 2446288.2315 0.0035 V 0.4894 2447689.2834 -0.0013 V 0.4769 2446522.2932 0.0026 V -0.3408 2447945.3699 0.0035 V -0.2728 2446523.2868 0.0025 V -0.3235 2447951.3619 0.0035 V -0.1686 2446551.3290 0.0012 V -0.2686 2447974.3920 0.0029 V 0.0125 2446557.3090 0.0008 V -0.2398 2447982.3456 0.0026 V -0.0260 2446563.2875 0.0005 V -0.1518 2447997.3175 0.0020 V -0.1164 2446569.3337 0.0001 V -0.1365 2448001.3090 0.0018 V -0.1847 2446578.2861 -0.0004 V -0.0045 2448003.2996 0.0017 V -0.1492 2446580.2872 -0.0005 V 0.0495 2448005.3185 0.0015 V -0.1704 2446583.2931 -0.0007 V -0.0215 2448011.2853 0.0012 V -0.1733 2446591.2928 -0.0012 V -0.0579 2448013.3108 0.0011 V -0.2176 2446595.3355 -0.0014 V -0.0386 2448015.2662 0.0010 V -0.1987 2446599.2920 -0.0016 V -0.0342 2448017.2634 0.0009 V -0.2415 2446612.2750 -0.0023 V -0.1665 2448019.2681 0.0008 V -0.2485 2446620.2910 -0.0026 V -0.2214 2448025.2676 0.0004 V -0.2684 2446623.2348 -0.0027 V -0.2376 2448033.3398 -0.0001 V -0.2182 2446635.2300 -0.0031 V -0.2891 2448036.3500 -0.0002 V -0.2462 2446862.3545 0.0033 V -0.1475 2448040.3290 -0.0005 V -0.2771 2446864.3336 0.0033 V -0.0207 2448042.3142 -0.0060 V -0.2863 2446883.3450 0.0028 V 0.3840 2448046.3241 -0.0008 V -0.2690 2446886.3151 0.0026 V 0.5006 2448048.3010 -0.0009 V -0.2224 2446891.3323 0.0024 V 0.5147 2448050.3160 -0.0011 V -0.1862 2446905.2895 0.0018 V -0.0778 2448052.3173 -0.0012 V -0.1488 2446907.2751 0.0017 V -0.1305 2448056.3124 -0.0014 V -0.1123 2446913.3226 0.0013 V -0.1832 2448061.3273 -0.0017 V 0.0589 2446934.3267 0.0001 V -0.3638 2448066.2761 -0.0019 V 0.1782 2446940.3341 -0.0002 V -0.3367 2448069.2701 -0.0020 V 0.2937 2446947.3245 -0.0006 V -0.2874 2448308.3797 0.0035 V -0.2385 2446955.3133 -0.0011 V -0.1583 2448312.3712 0.0035 V -0.2463 2446963.2991 -0.0015 V -0.1127 2448325.3889 0.0033 V -0.3516 2446968.2893 -0.0018 V -0.0889 2448350.3475 0.0025 V -0.2129 2447263.3145 0.0021 V -0.0934 2448355.3299 0.0023 V -0.0968 2447275.2997 0.0015 V 0.2621 2448357.3350 0.0022 V -0.0901 2447277.2881 0.0014 V 0.3374 2448362.3301 0.0020 V -0.0368 2447279.2887 0.0013 V 0.3761 2448365.3320 0.0018 V -0.0197 2447282.2823 0.0011 V 0.4770 2448380.2673 0.0010 V -0.0132 2447283.2750 0.0011 V 0.5288 2448392.3308 0.0003 V -0.1053 2447288.2641 0.0008 V 0.5713 2448402.3348 -0.0003 V -0.1812 2447289.2753 0.0007 V 0.5172 2448409.3311 -0.0007 V -0.2243 2447292.3084 0.0006 V 0.4092 2448411.3270 -0.0008 V -0.2247 2447294.3425 0.0004 V 0.2912 2448414.3187 -0.0010 V -0.2500 2447296.3294 0.0003 V 0.1340 2448418.3297 -0.0012 V -0.2886 2447298.3270 0.0002 V 0.0224 2448420.2885 -0.0013 V -0.2917 2447300.3403 0.0001 V -0.0423 2448430.2579 -0.0018 V -0.2578 2447303.3600 -0.0001 V -0.0979 2448436.2873 -0.0021 V -0.2645 2447314.3039 -0.0007 V -0.2065 2448439.2666 -0.0023 V -0.2726 2447588.3575 0.0034 V -0.0888 2448441.2651 -0.0024 V -0.2511 2447623.3079 0.0024 V -0.3107 2448445.2837 -0.0025 V -0.2384 2447626.3191 0.0022 V -0.2861 2448466.2246 -0.0032 V 0.3715 2447630.3074 0.0020 V -0.2839 Table II Variable-Comparison "B" magnitudes reduced to the UBV system, used to plot in Figure 1. JD HEL.CORR. F V-C JD HEL.CORR. F V-C 2446580.2876 -0.0005 B 1.1366 2447686.2874 -0.0011 B 1.6378 2446583.2935 -0.0007 B 1.0663 2447689.2844 -0.0013 B 1.5855 2446591.2931 -0.0012 B 0.9907 2447945.3699 0.0035 B 0.6832 2446595.3358 -0.0019 B 1.0086 2447951.3619 0.0035 B 0.8762 2446599.2925 -0.0016 B 1.0002 2447974.3920 0.0029 B 1.1047 2446612.2753 -0.0023 B 0.7877 2447982.3456 0.0026 B 1.0399 2446620.2914 -0.0026 B 0.7554 2447997.3175 0.0020 B 0.9231 2446623.2352 -0.0027 B 0.7333 2448001.3090 0.0018 B 0.8635 2446635.2305 -0.0031 B 0.6161 2448003.2996 0.0017 B 0.8768 2446862.3554 0.0033 B 0.8640 2448005.3185 0.0015 B 0.8494 2446864.3396 0.0033 B 1.0311 2448011.2853 0.0012 B 0.8389 2446883.3455 0.0028 B 1.4291 2448013.3108 0.0011 B 0.8122 2446886.3154 0.0026 B 1.4840 2448015.2662 0.0010 B 0.8383 2446891.3328 0.0024 B 1.5786 2448017.2634 0.0009 B 0.7701 2446905.2900 0.0018 B 0.9007 2448019.2681 0.0008 B 0.7674 2446907.2764 0.0017 B 0.8884 2448825.2676 0.0004 B 0.7147 2446934.3274 0.0001 B 0.5431 2448033.3398 -0.0001 B 0.7379 2446940.3347 -0.0002 B 0.5850 2448036.3500 -0.0002 B 0.7475 2446947.3258 -0.0006 B 0.6912 2448040.3290 -0.0005 B 0.7162 2446955.3138 -0.0011 B 1.1411 2448042.3142 -0.0060 B 0.6957 2446963.2997 -0.0015 B 0.9572 2448046.3241 -0.0008 B 0.7284 2446968.2899 -0.0018 B 1.0232 2448048.3010 -0.0009 B 0.7626 2447263.3149 0.0021 B 0.9607 2448050.3160 -0.0011 B 0.8185 2447275.3000 0.0015 B 1.2683 2448052.3173 -0.0012 B 0.8530 2447277.2885 0.0014 B 1.4147 2448056.3124 -0.0014 B 0.9037 2447279.2891 0.0013 B 1.4298 2448061.3273 -0.0017 B 1.1078 2447282.2828 0.0011 B 1.6031 2448066.2761 -0.0019 B 1.2419 2447283.2755 0.0011 B 1.6072 2448069.2701 -0.0020 B 1.3657 2447288.2644 0.0008 B 1.6399 2448308.3797 0.0035 B 0.7689 2447289.2758 0.0007 B 1.5687 2448312.3712 0.0035 B 0.6917 2447292.3094 0.0006 B 1.4615 2448325.3889 0.0033 B 0.6263 2447299.3428 0.0004 B 1.3776 2448350.3475 0.0025 B 0.7671 2447296.3298 0.0003 B 1.1748 2448355.3299 0.0023 B 0.8996 2447298.3276 0.0002 B 1.0062 2448357.3350 0.0022 B 0.9632 2447300.3415 0.0001 B 0.9431 2448362.3301 0.0020 B 1.0382 2447303.3705 -0.0001 B 0.8751 2448365.3320 0.0018 B 1.0576 2447314.3095 -0.0007 B 0.8149 2448380.2673 0.0010 B 1.0844 2447588.3587 0.0034 B 1.0276 2448392.3308 0.0003 B 0.9324 2447623.3082 0.0024 B 0.6656 2448402.3348 -0.0003 B 0.8638 2447626.3195 0.0022 B 0.6943 2448409.3311 -0.0007 B 0.8254 2447630.3079 0.0020 B 0.7050 2448411.3270 -0.0008 B 0.8005 2447635.3185 0.0018 B 0.7138 2448414.3187 -0.0010 B 0.7522 2447649.2897 0.0010 B 0.7122 2448418.3297 -0.0012 B 0.6854 2447656.2745 0.0006 B 0.7696 2448420.2885 -0.0013 B 0.6602 2447659.2912 0.0005 B 0.8051 2448430.2579 -0.0018 B 0.7529 2447669.3158 -0.0001 B 1.2903 2448436.2873 -0.0021 B 0.7481 2447672.3084 -0.0003 B 1.3812 2448439.2666 -0.0023 B 0.7518 2447677.3184 -0.0006 B 1.5378 2448441.2651 -0.0024 B 0.7334 2447679.3072 -0.0007 B 1.5653 2448445.2837 -0.0025 B 0.7878 2447683.2891 -0.0010 B 1.6533 2448466.2246 -0.0032 B 1.4953 Very little, however, is available concerning the secondary minimum. The phase diagram in Figure 1 is presented here in the form of V-C which is felt may be of more use than the original form of relative magnitude. The magnitude differences in V and B colours are listed in Tables I and II respectively. For detail of equipment, observation and reduction techniques the reader should refer to the original paper. L. PAZZI Nigel Observatory P.O. Box 211 Nigel 1490 South Africa References: Knipe, C.F.G., 1972, Mon. Not. Ast. Soc. Sou. Afr., 31, 25. [BIBCODE 1972MNSSA..31...25K ] Kohoutek, L., 1988, IBVS 3272. Kviz, Z. & Rufener, F., 1988, IBVS 3158. Marino, B.F., Walker, W.S.G., & Herdman, G., 1984, IBVS 2582. Marino, B.F., Walker, W.S.G., & Budding, E., 1988 Astrophys. Space Sci., 150, 103. [BIBCODE 1988Ap&SS.150..103M ] Menzies, J.W. & Spencer Jones, J., 1984 IBVS No. 2623. Pazzi, L., 1989, Mon. Not. Ast. Soc. Sou. Afr., 48, 23. [BIBCODE 1989MNSSA..48...23P ] Plavec, M. J., 1984, IBVS 2524.