COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 4085 Konkoly Observatory Budapest 14 September 1994 HU ISSN 0374 - 0676 PHOTOELECTRIC OBSERVATIONS OF VV Ori IN R AND I VV Ori (BD-1d943) is a beta Lyr type eclipsing binary, consisting of two main sequence stars of spectral type B. The observations were performed during 55 nights between December 1990 and February 1994. The total number of observations obtained are 2692 points for each color (Table 1). Throughout the author's observations, HR1873 (BD-1d949, sp=B3V) was used as the comparison star and HR 1861 (BD-1d935, sp=B1V) was used as a check star, which are the same ones as used in the previous work by Duerbeck (1975). However, from the author's observations it was found that HR 1873 abruptly changed its brightness in January 1992. The constancy of the star HR 1861 was verified by Huffer and Kopal (1951), Duerbeck (1975) and Chambliss (1982). All the observations have been transformed to Johnson's standard system. The obtained light and color curves in R and I between 1993 and 1994 are shown in Figure 1. The obtained new times of minima and previous ones derived by other authors (see Duerbeck, 1975) are shown in Table 2. We have obtained the new light elements: Min I(Hel J.D.) = 2440890.5112 + 1.48537752d x E [FIGURE 1] Figure 1. Light and color curves of VV Ori Table 1. The data of present observations (VV Ori) Season Nights Data points minima I minima II 1990 Dec.- 1991 Feb. 11 449 2 0 1991 Nov.- 1992 Feb. 15 755 0 1 1992 Nov.- 1993 Feb. 18 844 1 2 1993 Nov.- 1994 Feb. 11 644 2 2 Table 2. New times of minima of VV Ori Year J.D.(Hel.) E O - C Author 24... 1913 19836.021 -14174.5 -0.007 Daniel 1913 20095.2218 -14000 -0.0041 Hertzsprung 1922 23401.680 -11774 0.004 Stearns 1930 26035.251 -10001 0.000 Zverev 1931 26387.282 -9764 -0.003 Dufay 1934 27443.3878 -9053 -0.0007 Martin 1934 27464.184 -9039 0.000 Schneller 1938 29225.849 -7853 0.008 Wood 1938 29234.756 -7847 0.002 Wood 1939 29307.539 -7798 0.002 Wood 1939 29335.758 -7779 -0.002 Wood 1969 40545.899 -232 -0.005 Atkins 1973 42041.6826 775 0.0038 Duerbeck 1976 42788.8291 1278 0.0054 Chambliss 1976 42791.8018 1280 0.0074 Chambliss 1976 42794.7704 1282 0.0052 Chambliss 1976 42803.6832 1288 0.0058 Chambliss 1978 43510.7218 1764 0.0047 Chambliss 1990 48249.0735 4954 0.0021 Arai 1990 48255.0144 4958 0.0014 Arai 1992 48636.0120 5214.5 -0.0003 Arai 1992 48962.0520 5434 -0.0007 Arai 1992 48982.1030 5447.5 -0.0023 Arai 1992 48988.0447 5451.5 -0.0021 Arai 1993 49320.0262 5675 -0.0024 Arai 1993 49337.1077 5686.5 -0.0028 Arai 1993 49340.0805 5688.5 -0.0007 Arai 1994 49372.0115 5710 -0.0053 Arai [FIGURE 2] Figure 2. O-C diagram of VV Ori (1913-1994) Table 3. Delta R, Delta I and Delta (R-I) values of VV Ori at maxima and minima phase Year Delta R Delta I Delta (R-I) 1991 -0.879 -0.835 -0.044 maxima I 1992 -0.886 -0.858 -0.028 1993 -0.880 -0.849 -0.031 1994 -0.900 -0.864 -0.035 1991 -0.577 -0.557 -0.020 minima I 1992 -0.580 -0.562 -0.018 1993 -0.580 -0.552 -0.028 1994 -0.586 -0.557 -0.029 1991 -0.902 -0.869 -0.033 maxima II 1992 -0.876 -0.843 -0.033 1993 -0.896 -0.849 -0.047 1994 -0.895 -0.857 -0.038 1991 -0.730 -0.693 -0.037 minima II 1992 -0.725 -0.690 -0.036 1993 -0.723 -0.682 -0.041 1994 -0.727 -0.682 -0.045 Figure 2 shows the O-C diagram where the data of other authors are also plotted. Table 3 shows the variations of Delta R, Delta I at maxima and minima respectively. I would like to express my hearty thanks to Prof. M. Kitamura and Dr. A. Okazaki for valuable suggestions and encouragement. Kikuichi ARAI Kuki-Hokuyo Senior High School, Kuki, Saitama, 346 Japan and JAPOA^1 Member References: Atkins, H. L., 1971, MS Thesis, Univ. of Athens, Georgia, (unpublished.) Chambliss, C., Leung, K. C., 1982, Astrophys. J. Suppl., 49, 531 [BIBCODE 1982ApJS...49..531C ] Daniel, Z., 1913, Astron. Nachr., 194, 15 [BIBCODE 1913AN....194...15D ] Duerbeck, H. W., 1975, Astron. Astrophys. Suppl., 22, 19 [BIBCODE 1975A&AS...22...19D ] Dufay, J., 1947, Ann. Astrophys., 10, 158 [BIBCODE 1947AnAp...10..158D ] Hertzsprung, E., 1919, Publ. Astrophys. Obs. Potsdam, 23, 1 Huffer, C. M. and Kopal, Z., 1951, Astrophys. J., 114, 297 [BIBCODE 1951ApJ...114..297H ] Martin, W. C., 1934, B.A.N., 7, 174 [BIBCODE 1934BAN.....7..174M ] Schneller, H., 1936, Kleinere Veroff. Berlin-Babelsberg, 17, 17 Stearns, C. L., 1926, Trans. Astron. Obs. Yale Univ., 3, 68 Wood, F. B., 1946, Contr. Princeton Univ. Obs., 21, 25 [BIBCODE 1946CoPri..21....1W ] Zverev, M., 1936, Trudy gos. Astron. Ins. Sternberg, 8, 50 and 123 1 JAPOA: Japan Amateur Photoelectric Observers Association