COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 784 Konkoly Observatory Budapest 1973 April 19 PHOTOELECTRIC OBSERVATIONS OF beta ARIETIS Beta Arietis has been known as a spectroscopic binary star with a highly eccentric orbit of e=0.892 (Petrie 1938), and it was suspected by Dommanget that it might have light variation due to a periastron effect. The first photoelectric observation was made by Lovell and Hall (1971) for light variation, but they concluded from their fifteen observations that there is no periastron effect larger than about 0.01m. In view of rather small number of their observations, we made further BV photoelectric observations in order to check their conclusion. Our observations were made on sixteen nights in 1972-73 with the 8-inch refractor at the Education Centre of Kanagawa Prefecture. In these observations, gamma^1 + gamma^2 Arietis was used as the comparison star, which was the same one as used by Lovell and Hall. Correcting for differential extinction, the differential BV standard magnitudes between beta Arietis and the comparison were deduced as shown in the following table. In the table, the phases are calculated from periastron with Petrie's elements (1938): Hel JD 2428010.944 + 106.9973d E. The standard error of a single differential observation can be estimated from differential brightnesses out of periastron to be 0.02m ~ 0.03m for both colours. Unfortunately, owing to unfavourable weather condition, no observation was attained on the night nearest periastron. However, even though we consider such amount of accidental errors of observations, it does not seem that beta Arietis has any appreciable light variation of more than 0.02m around the periastron, in agreement with the previous conclusion by Lovell and Hall. I would like to express my hearty thanks to Prof. M. Kitamura at Tokyo Astronomical Observatory for his suggestion of this programme and kind guidance. Thanks are also due to Dr. J. Dommanget at the Royal Observatory of Belgium for his kind information. ---------------------------------------------------------------------- Hel JD DeltaV DeltaB phase Hel JD DeltaV DeltaB phase 2441000+ 2441000+ ---------------------------------------------------------------------- 635.0838 -1.215 -1.045 -71.515 694.9140 -1.198 -1.053 -11.684 .0879 1.213 1.022 .511 .9175 1.231 1.035 .681 .0928 1.220 1.030 .506 .9203 1.199 1.037 .678 .0984 1.232 1.034 .500 .9240 1.233 1.026 .674 646.0202 1.229 1.042 -60.578 701.8717 1.225 1.068 -4.727 .0243 1.217 1.048 .574 702.9390 1.175 1.067 -4.659 .0285 1.203 1.030 .570 .9421 1.189 1.043 .656 649.9983 1.182 - -56.600 .9494 1.174 1.066 .649 650.0021 1.186 - .596 .9608 1.184 1.056 .638 .0066 1.199 - .592 703.8891 1.194 1.054 -2.709 653.9441 1.215 1.024 -52.654 .8919 1.208 1.048 .707 .9476 1.213 1.020 .651 .8953 1.216 1.027 .703 .9510 1.212 1.016 .647 .8985 1.229 1.061 .700 .9663 1.199 1.061 .632 707.8992 1.187 1.042 +1.301 681.9059 1.219 1.055 -24.693 .9288 1.235 1.072 .330 .9100 1.217 1.042 .688 .9316 1.207 1.047 .333 .9142 1.199 1.038 .684 710.9052 1.197 1.052 +4.307 686.9086 1.224 1.061 -19.690 .9079 1.209 1.053 .310 .9148 1.213 1.063 .684 .9107 1.196 1.058 .312 .9207 1.200 1.072 .678 .9132 1.205 1.051 .315 691.9091 1.202 1.052 -14.689 715.8878 1.229 1.034 +9.289 .9137 1.210 1.063 .685 .8906 1.229 1.037 .292 .9182 1.223 1.064 .680 .8933 1.228 1.039 .295 .9241 1.244 1.051 .674 .8968 1.231 1.031 .298 693.9054 1.209 1.020 -12.693 724.8906 1.256 1.010 +18.292 .9102 1.212 1.017 .688 .8940 1.227 1.019 .296 .9141 1.208 1.023 .684 .8975 1.221 1.024 .299 .9179 1.229 1.032 .681 .9010 1.236 1.050 .303 ---------------------------------------------------------------------- [FIGURE 1] HITOSHI OGATA Education Centre of Kanagawa Prefecture, Japan. References: Dommanget, J. 1972 (private communication to Prof. Kitamura). Lovell, L.P. and Hall, D.S. 1971, Pub. A.S.P. 83. 360. [BIBCODE 1971PASP...83..360L ] Petrie, R.N. 1938, Pub. Dominion Astrophy.Obs. 7, 105. [BIBCODE 1938PDAO....7..105P ]