COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 4045 Konkoly Observatory Budapest 4 July 1994 HU ISSN 0374 - 0676 NEW EPHEMERIS OF THE BINARY SYSTEM 44i BOOTIS Photometric observations of 44i Bootis were made at Timisoara Observatory during July and August 1993. Our photometric instrument consists of an EMI 9862Q photomultiplier attached to a 30 cm Cassegrain telescope. Observations were carried out using V filter (OG/2mm). As comparison star BD+48d2262 was used. For the six observed minima we give in Table I the Julian dates and their mean errors, computed using Kwee-Van Woerden method. Table I No. HEL.JD. sigma Obs. Filter 2440000.+ 1 9178.4204 0.0015 Gherega V 2 9186.4534 0.0005 " V 3 9200.3765 0.0027 " V 4 9207.3427 0.0019 " V 5 9214.3066 0.0008 " V 6 9215.3780 0.0009 " V [FIGURE 1] Table II Hel.JD. O-C E Ref. HeI.JD. O-C E Ref. 2440000+ days cycle no. 2440000+ days cycle no. 2531.4512 0.0080 -4007.0 [4] 6640.3005 0.0008 11335.0 [1] 2553.4119 0.0077 -3925.0 " 66382939 0.0028 11327.5 " 2837.5649 0.0063 -2864.0 " 6973.3286 -0.0022 12578.5 [11] 2841.5831 0.0072 -2849.0 " 6973.3296 -0.0012 12578.5 " 2953.5306 0.0070 -2431.0 " 6973.3352 0.0044 12578.5 " 3604.5880 0.0000 0.0 [5] 6977.3550 0.0069 12593.5 " 3607.5379 0.0039 11.0 " 6977.3510 0.0029 12593.5 " 3607.8107 0.0089 12.0 " 6977.3557 0.0076 12593.5 " 3614.3611 -0.0022 36.5 [14] 6984.3159 0.0046 12619.5 " 3614.5000 0.0028 37.0 " 6984.3174 0.0061 12619.5 " 3615.5710 0.0025 41.0 " 6984.3235 0.0122 12619.5 " 3616.3764 0.0044 44.0 " 6986.3253 0.0054 12627.0 " 3974.4464 0.0024 1381.0 [7] 6986.3238 0.0039 12627.0 " 3974.5788 0.0009 1381.5 " 6986.3257 0.0058 12627.0 " 4706.5219 -0.0013 4114.5 " 7242.4882 0.0008 13583.5 [15] 4709.4679 0.0013 4125.5 " 7242.6248 0.0035 13584.0 " 4345.5067 0.0015 2766.5 [10] 7245.4395 0.0061 13594.5 " 4365.4569 -0.0007 2841.0 " 7245.5701 0.0028 13595.0 " 4366.5290 0.0002 2845.0 " 7338.3675 0.0014 13941.5 " 4349.3904 0.0019 2781.0 [2] 7338.5006 0.0006 13942.0 " 4351.5314 0.0004 2789.0 ' 7340.3756 0.0009 13949.0 " 4354.4773 0.0002 2800.0 " 7341.3174 0.0053 13952.5 " 4355.5500 0.0017 2804.0 " 7341.4445 -0.0015 13953.0 " 4356.3523 0.0005 2807.0 " 7319.7446 -0.0082 13872.0 [19] 4366.7971 0.0004 2846.0 [17] 7319.7495 -0.0033 13872.0 " 4390.9032 0.0029 2936.0 " 7319.7491 -0.0037 13872.0 " 4409.7855 0.0041 3006.5 " 7322.7008 0.0020 13883.0 " 4811.7794 0.0039 4507.5 ' 7322.6999 0.0011 13883.0 " 5473.8187 -0.0017 6979.5 " 7359.3920 0.0022 14020.0 [18] 5476.9019 0.0015 6991.0 " 7364.3469 0.0025 14038.5 " 5477.8383 0.0006 6994.5 " 7365.4180 0.0023 14042.5 " 5478.7745 -0.0006 6998.0 " 7371.4438 0.0022 14065.0 " 5488.8162 -0.0020 7035.5 " 7375.3270 0.0021 14079.5 " 5468.4684 0.0043 6959.5 [13] 7388.3163 0.0022 14128.0 " 5468.4649 0.0008 6959.5 " 7393.4050 0.0024 14147.0 " 5482.5245 -0.0000 7012.0 " 7739.2988 0.0099 15438.5 [12] 5482.5259 0.0014 7012.0 " 8086.3840 0.0035 16734.5 " 5870.4565 -0.0017 8460.5 " 8086.3881 0.0076 16734.5 " 6640.3026 0.0029 11335.0 [1] 8086.3877 0.0072 16734.5 " 6638.2938 0.0027 11327.5 " 8091.3346 -0.0005 16753.0 " 8091.3346 -0.0005 16753.0 [12] 9162.3508 0.0134 20752.0 [16] 8429.8634 0.0070 18017.0 [3] 9162.3503 0.0129 20752.0 " 8429.8629 0.0065 18017.0 " 9168.3732 0.0099 20774.5 " 8429.8632 0.0068 18017.0 " 9168.3729 0.0096 20774.5 " 8437.7649 0.0078 18046.5 " 9168.3740 0.0107 20774.5 " 8437.7663 0.0092 18046.5 " 9177.3478 0.0126 20808.0 " 8437.7623 0.0052 18046.5 " 9177.3482 0.0130 20808.0 " 8439.7698 0.0041 18054.0 " 9177.3479 0.0127 20808.0 " 8439.7739 0.0082 18054.0 " 9178.4204 0.0140 20812.0 This 8439.7690 0.0033 18054.0 " 9186.4534 0.0124 20842.0 paper 9099.4042 0.0039 20517.0 [16] 9200.3765 0.0090 20894.0 " 9149.3581 0.0099 20703.5 " 9207.3427 0.0120 20920.0 " 9149.3664 0.0182 20703.5 " 9214.3066 0.0126 20946.0 " 9159.4094 0.0180 20741.0 " 9215.3780 0.0127 20950.0 " The O-C residuals were computed using the ephemeris: Min I = J.D. 2443604.5880 + 0.26781753d x E (1) given by Oprescu et al. (1989). In Table II we give the O-C residuals, computed for the Julian dates of minima, given in references, completed with O-C values from our observations. In Figure 1 we plotted the O-C residuals versus the number of periods denoted by E. Considering a linear ephemeris, the least squares method yields: Min I = 2443604.5887d + 0.26781785d x E (2) +/-0.0006d +/- 0.00000004d Or, considering quadratic ephemeris, the same method leads to: Min I = 2443604.5914d + 0.26781662d x E + 0.62d x 10^-10 x E^2 (3) +/-0.0004d+/-0.00000009d +/-0.05d x 10^-10 The comparison of the two fits (ephemerides (2) and (3)) is seen in Figure 1. We found that quadratic ephemeris fits better the observations. Octavian GHEREGA Ladislau FARKAS Alexandru HORVATH Astronomical Institute of Romanian Academy, Timisoara Observatory, Piata Axente Sever No. 1 Timisoara, 1900 Romania References: 1. Al-Naimiy, H. A., Fleyeh, H. A., Al-Sikab, A. O., Al-Razzaz, J. M., 1986, IBVS, No. 2956 2. 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