COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 2198 Konkoly Observatory Budapest 1982 September 14 HU ISSN 0374-0676 A NOTE ON TWO Be STARS * HD 30076 HD 30076 (= HR 1508 = 56 Eri) is known as a variable at least since Cousins (1963). It appears also in the Second Catalogue of Suspected Variable Stars (Kukarkin et al., 1965) under the number 6131. The spectral type given by Cousins was B5ne and the range of variation in V was 5.90 - 5.99. Later UBV observations by Feinstein (1968) pointed out variations of 0.12m in V, 0.03m in B-V and U-B (see Table III) in 35 months. However, HD 30076 is listed without indication of variability both by Crawford et a.l. (1971) and by Gronbech and Olsen (1976a). We were unaware of this variability and HD 30076 was included in several occasions as a secondary reference or as a comparison star in our observing runs. uvby observations of this star have then been carried out at the ESO 1m telescope in September 1980 and August 1981, and at the Danish 50cm telescope at La Silla in January 1982. The 1m telescope was equipped with a standard one- channel photometer (Danks, 1981, Chap. II.C.1 and III.B.3) and the Danish 50cm telescope with a simultaneous four-channel photometer (Danks, 1981, Chap. II.H.1 and III.B.8). The integrations were repeated until reaching a satisfactory precision of the counts. For each run, the typical overall agreement of the observations with the international uvby standard system was for V_m, b-y, m_1, c_1 respectively less than 0.011m, 0.006m, 0.008m and 0.009m. The results are presented in Tables I and II. *Based on observations collected at the European Southern Observatory, La Silla, Chile Table I uvby observations of HD 30076 at the ESO 1m telescope (Sept. 1980 and Aug. 1981) JD_hel V b-y m_1 c_1 2,440,000+ 4487.8350 5.886 -0.013 0.066 0.078 4835.8886 5.842 -0.033 0.074 0.119 4839.8748 5.874 -0.032 0.075 0.130 4841.8664 5.893 -0.034 0.075 0.119 Table II uvby observations of HD 30076 at the Danish 50cm telescope (Jan. 1982) JD_hel V b-Y m_1 c_1 2,440,000+ 4972.6373 5.909 -0.031 0.064 0.148 4973.6607 5.906 -0.031 0.064 0.163 4974.6450 5.934 -0.016 0.059 0.128 4975.6371 5.879 -0.017 0.055 0.131 4978.5979 5.898 -0.027 0.064 0.144 4979.6252 5.979 -0.030 0.069 0.145 4980.5861 5.923 -0.030 0.070 0.145 4981.5899 5.898 -0.032 0.073 0.146 4982.6172 5.923 -0.035 0.072 0.161 4983.6289 5.939 -0.023 0.069 0.137 4984.6327 5.954 -0.021 0.067 0.146 4985.6248 5.948 -0.026 0.065 0.145 In Tables III and IV, we have gathered past observations of this star. The indices in the seven-colour (Geneva) system are the following (Rufener, 1981): m_v = 5.890, U = 0.391, V = 1.065, B_1 = 0.797, B_2 = 1.585, V_1 = 1.758 and G = 2.261. The star was pointed out as a suspected variable in Rufener and Bartholdi (1982) with sigma_v = 0.035 and sigma(colours) - 0.007. Feinstein (1968) found also R = 6.69 and R-I = -0.06 from two measurements in November 1965. It is not easy to draw a light curve with all these data because the epochs are missing for most observations. But clearly, from our own observations and from the past data, variability appears to be present both on a short and long timescales with different amplitudes difficult to separate: daily fluctuations of a few hundreths of magnitude, while monthly or yearly effects are more important. The total variability seems to be fairly typical for a Be star and amounts to (from individual variations): 0.22m in V, 0.07m in b-y, 0.05m in m_1, 0.15m in c_1, 0.02m in 0.06m in U-B and in B-V. Table III UBV observations of HD 30076 V B-V U-B n Ref. 5.92 -0.11 -0.83 Mendoza (1958) 5.90 -0,11 -0.81 Cousins (1963) 5.90 -0.13 Lake (1963) 5.91 -0.09 -0.77 4 Feinstein (1968) (Jan.1963) 5.81 -0.10 -0.80 4 " (Dec.1964) 5.79 -0.07 -0.77 4 " (Nov.1965) 5.86 -0.09 -0.80 4 Crawford et al.(1971) 5.90 -0.11 -0.81 Nicolet (1978) Table IV uvby beta observations of HD 30076 V b-y m_1 c_1 n beta n Ref. 5.86 0.006 0.040 0.069 4 2.469 3 Crawford et al. (1971) 5.800 0.013 Gronbech (1974) (JJ_hel 42,000.79-83) 5.765 0.023 " 1.74-80) 5.794 0.024 " 2.67-82) 5.780 0.017 " 3.75) 5.760 0.023 " 4.67) 5.762 0.015 " 5.76) 2.470 3 Feinstein (1974) (observ. in 1970) 2.484 3 " 1972) 0.006 0.040 0.069 2.469 Hauck & Mermilliod (1975) 5.836 0.034 0.021 0.015 2 Gronbech & Olsen (1976a) +-0.009 +-0.002 +-0.009 +-0.005 2.463 3 Gronbech & Olsen (1976b) +-0.010 5.886 -0.013 0.066 0.078 1 Table I (1980) 5.870 -0.032 0.074 0.123 3 Table I (1981) +-0.026 +-0.001 +-0.001 +-0.006 5.924 -0.027 0.066 0.145 12 Table II +-0.028 +0.006 +-0.005 +-0.010 Table V uvby observations of HD 172256 J.D._hel V b-y m_1 c_1 2,440,000+ 4838.4851 8.667 0.120 -0.013 0.159 .5008 8.662 0.112 0.003 0.156 .5276 8.658 0,112 -0.005 0.167 .5371 8.661 0.119 -0.021 0.180 .5585 8.667 0.111 -0.007 0.180 .5675 8.671 0.113 -0.003 0.165 .5837 8.686 0.117 -0.013 0.166 .5939 8.690 0.113 -0.002 0.151 .6179 8.734 0.107 -0.011 0.149 .6285 8.740 0.101 0.004 0.129 .6455 8.743 0.110 -0.008 0.124 .6558 8.751 0.108 -0.006 0.124 .6733 8.742 0.106 0.001 0.111 .6826 8.733 0.108 -0.002 0.115 4839.4795 8.674 0.115 -0.007 0.147 .4903 8.673 0.109 0.005 0.140 .5808 8.740 0.112 0.000 0.162 .5955 8.740 0.121 -0.011 0.168 .6852 8.738 0.117 -0.003 0.131 .6971 8.729 0.124 -0.021 0.146 4840.5550 8.750 0.119 -0.007 0.173 .5660 8.755 0.121 -0.008 0.169 4841.5610 8.680 0.117 -0.005 0.153 .5726 8.678 0.122 -0.018 0.161 4842.5432 8.693 0.119 -0.011 0.144 .5531 8.701 0.117 -0.009 0.143 4843.6192 8.755 0.120 -0.008 0.154 .6291 8.761 0.121 -0.006 0.156 4844.6194 8.704 0.114 -0.006 0.154 .6281 8.696 0.117 -0.009 0.153 overall average (n = 30) 8.709+-0.035 0.115+-0.005 -0.008+-0.006 0.151+-0.017 Table V (cont.) daily averages 2,400,000+ 4838(n =14) 8.700+-0.037 0.111+-0.005 -0.006+-0.007 0.148+-0.024 4839(n = 6) 8.716+-0.033 0.116+-0.005 -0.006+-0.009 0.149+-0.014 4840(n = 2) 8.752+-0.003 0.120+-0.002 -0.008+-0.001 0.171+-0.003 4841(n = 2) 8.679+-0.002 0.119+-0.003 -0.012+-0.009 0.157+-0.006 4842(n = 2) 8.697+-0.005 0.118+-0.002 -0.010+-0.001 0.143+-0.001 4843(n = 2) 8.758+-0.004 0.120+-0.001 -0.007+-0.002 0.154+-0.002 4844(n = 2) 8.700+-0.005 0.116+-0.002 -0.007+-0.003 0.153+-0.001 mean of the daily averages (n = 7) 8.715+-0.030 0.117+-0.003 -0.008+-0.002 0.154+-0.009 HD 172256 HD 172256 (=SAO 187112) was found variable when used as a comparison in our observations of V348 Sgr (Heck et al., 1982), which is not too surprising since it is listed as a Be star under # 606 in Wackerling's catalogue (1970). Its radial velocity is +3.3 km sec^-1 (Wilson, 1953). Our detailed observations are gathered in Table V. They were carried out in August 1981 at the ESO 1m telescope and the characteristics are the same as for HD 30076. The daily averages are also given in Table V. We have been unable to extract any periodicity out of the variations. Here the amplitudes are relatively small, especially in b-y and m_1. It would be interesting to check the variability on a longer timescale. A. HECK ^1 AND J. MANFROID ^2 ** 1 IUE Observatory, Astronomy Division, ESTEC, European Space Agency, Villafranca Satellite Tracking Station, Apartado 54065, Madrid, Spain 2 Departement d'Astrophysique de l'Universite de Liege, avenue de Cointe 5, B-4200 Cointe-Ougree, Belgium ** Chercheur Qualifie F.N.R.S. References: Cousins, A.W.J. 1963, Monthly Not. Astron. Soc. South Africa 22,58 [BIBCODE 1963MNSSA..22...58C ] Crawford, D.L., Barnes, J.V., Golson, J.C. 1971, Astron. J. 76, 1058 [BIBCODE 1971AJ.....76.1058C ] Danks, A.C. 1981, The ESO User's Manual, European Southern Observatory [BIBCODE 1981eum..book.....D ] Feinstein, A. 1968, Zeit. f. Astrophys. 68, 29 [BIBCODE 1968ZA.....68...29F ] Feinstein, A. 1974, Monthly Not. Roy. Astron. Soc. 169, 171 [BIBCODE 1974MNRAS.169..171F ] Gronbech, B. 1974, IAU Comm. 27 Inf. Bull. Var. Stars 890 Gronbech, B., Olsen, E.H. 1976a, Astron. Astrophys. Suppl. 25, 213 [BIBCODE 1976A&AS...25..213G ] Gronbech, B., Olsen, E.H. 1976b, Astron. Astrophys. Suppl. 27, 443 [BIBCODE 1977A&AS...27..443G ] Hauck, B., Mermilliod, M. 1975, Astron. Astrophys. Suppl. 22, 235 [BIBCODE 1975A&AS...22..235H ] Heck, A., Houziaux, L., Manfroid, J. 1982, IAU Comm, 27 Inf. Bull. Variable Stars 2184 Kukarkin, B.V., Kholopov, P.N., Efremov, Y.N., Kurochkin, N.E. 1965, Second Catalogue of Suspected Variable Stars, Moscow [BIBCODE 1965CSV...C......0K ] Lake, R. 1963, Monthly Not. Astron. Soc. South Africa 22, 79 [BIBCODE 1963MNSSA..22...79L ] Mendoza, E.E.V. 1958, Astrophys. J. 128, 207 [BIBCODE 1958ApJ...128..207M ] Nicolet, B. 1978, Astron. Astrophys. Suppl. 34, 1 [BIBCODE 1978A&AS...34....1N ] Rufener, F. 1981, Astron. Astrophys. Suppl. 45, 207 [BIBCODE 1981A&AS...45..207R ] Rufener, F., Bartholdi, P. 1982, Astron. Astrophys. Suppl. 48, 503 [BIBCODE 1982A&AS...48..503R ] Wackerling, L.R. 1970, Mem. Roy. Astron. Soc. 73, 153 [BIBCODE 1970MmRAS..73..153W ] Wilson, R.E. 1953, General Catalogue of Stellar Radial Velocities, Carnegie Inst. Washington 601 [BIBCODE 1953GCRV..C......0W ]