COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1164 Konkoly Observatory Budapest 1976 August 11 LIGHT VARIATIONS OF THE JOHNSON'S STANDARD STAR BD +3d4065 The Be star BD +3d4065 has been observed repeatedly from 1968 to 1976 with the 40 cm refractor of the Teramo Observatory in the course of a routine program of observation of standard stars as a part of a general photometric program. The star, which is listed in the Johnson's catalogue (Johnson and Harris, 1954) with the V magnitude 6.82, appeared during the last 8 years to fade slowly from 6.9 to 7.2 and then to recover its primary brightness (the result of an observation yielding the magnitude 7.51 is to be considered doubtful being based on a single measure). The magnitude given in the Johnson's catalogue may be roughly located at the epoch 1952 +- 1 year; other magnitude determinations have been picked out from the literature (Mendoza, 1958; Cousins and Stoy, 1963; Johnson and Borgman, 1963; Nekrasova et al., 1965). All these magnitudes are listed in the Table together with the determinations performed at Teramo; the mean accuracy of the Teramo magnitudes is +- 0.03. The light curve shows slow fluctuations between 6.8 and 7.2. The spectrum of the star is recorded in the catalogue of B stars with bright hydrogen lines ( Merrill and Burwell, 1933) as B2se; Cousins and Stoy classified it as B0.5 IV. According to Rosino (1976) on a plate obtained at the Asiago Observatory in May 1976 with a dispersion of 60 Angstrom/mm the spectrum belongs to the class B0 Ib with Halpha in emission; all the other lines appear as sharp absorptions and no evidence of P Cygni effect has been found. The presence of light fluctuations in some Be stars is since long known: the cases of P Cygni, theta CrB, and gamma Cas which undergo brightness fluctuations of a few tenths show how difficult and deceiving is the attempt of analysing the light curve (see f.i. De Groot, 1968). The discordance between the luminosity classification stated by Cousins and that observed by Rosino is rather puzzling. Nevertheless the s character of the spectral lines was already reported by Merrill and Burwell, moreover Mendoza states that with some certainty [FIGURE 1] Light curve of BD +3d4065 from 1952 to 1976. Table Photoelectric Observations of 3D +3d4065 J.D. V B-V Source J.D. V B-V Source 24 24 34200: 6.82 +.02 Johnson & Harris 40710 7.10 +.07 Present 35400: 6.82 .02 Mendoza 40735 7.09 .07 Comm. 37100: 6.86 .03 Cousins & Stoy 40769 7.09 .08 " 37200: 6.83 .02 Nekrasova et al. 40774 7.06 .06 " 37800: 6.89 .03 Johnson & Morgan 40782 7.06 .05 " 39928 6.89 .01 Present Comm. 40794 7.09 .05 " 39940 6.90 .03 " 40866 7.08 .07 " 39941 7.00 .10 " 41134 7.09 .09 " 39968 6.91 .07 " 41144 7.07 .08 " 39970 6.93 .04 " 41151 7.08 - " 39972 6.95 .05 " 41244 7.17 .07 " 39973 6.91 .02 " 41250 7.17 .05 " 39985 6.90 .02 " 41502 7.23 .10 " 40029 6.88 .02 " 41536 7.17 .04 " 40035 6.90 .04 " 41544 7.16 .06 " 40066 6.96 .03 " 41628 7.22 .10 " 40151 6.94 .03 " 41863 7.51 .06 " 40388 6.95 .07 " 41893 7.16 .06 " 40389 6.92 .07 " 41902 7.19 .06 " 40416 6.97 .06 " 41955 7.13 .04 " 40418 6.96 .06 " 42276 6.99 .06 " 40420 6.93 .06 " 42988 6.97 - " 40454 6.90 .04 " The dates marked with a colon are uncertain within a few hundreds of days. the luminosity classes of the stars of a list including BD+3d4065 lie between III and V on the MK system even though accurate luminosity classification had not been attempted. P. TEMPESTI and R. PATRIARCA Osservatorio Astronomico di Teramo, Italy References: Cousins, A.W.J. and Stoy, R.H. 1963, Royal Obs. Bull. N. 64 [BIBCODE 1963pmcs.book.....C ] De Groot, M. 1968, B.A.N. 20, 225 [BIBCODE 1969BAN....20..225D ] Johnson, H.L. and Borgman, J. 1963, B.A.N. 17, 115 [BIBCODE 1963BAN....17..115J ] Johnson, H.L. and Harris, D.L. 1954, Ap.J. 120, 196 [BIBCODE 1954ApJ...120..196J ] Mendoza, E.E. 1958, Ap.J. 128, 207 [BIBCODE 1958ApJ...128..207M ] Merrill, P.W. and Burwell C.G. 1933, Ap.J. 78, 87 [BIBCODE 1933ApJ....78...87M ] Nekrasova, S.V., Nikonov, V.B., Rybka, E. 1965, Izv.Krym.Astrofiz. Obs. 34, 69 [BIBCODE 1965IzKry..34...69N ] Rosino, L. 1976, Private communication