COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 3624 Konkoly Observatory Budapest 17 June 1991 HU ISSN 0374-0676 THE UNUSUAL T TAURI TYPE STAR V350 CEPHEI The variable V350 Cep (SVS 2246) was found in the star formation region NGC 7129 by Gyulbudaghian and Sarkisyan (1978a, b). In 1977-1978 its brightness was near 17.5m B and 16.5m V. The star was not seen on the Palomar Sky Survey print made on 5-6 Aug. 1954 (the limit was 21.1m B). According to Gyulbudaghian (1980) V350 Cep was not seen on 70 plates with the limit 15- 17.5m pg, obtained during 1936-1966. Preliminary results of photographic observations, given by Pogosyants (1985) are erroneous. All our B and V data are revised in this paper. We measured V350 Cep on 59 plates from Sternberg Institute collection. Seven estimates in the Baldone Observatory (Latvia) were made by Dr. A. Alksnis. The sequence of comparison stars calibrated through photoelectric standards in cluster NGC 7142 (van den Bergh and Heeringa, 1970) is presented in Table I and in Figure 1. Table II contains our observations. The light curve of V350 Cep, based on our data and all published data is shown in Figure 2. For the first time the star's brightness has exceeded our plate limit of ~19.0m B and ~18.5m V in 1971. The maximum brightness of the star during the observations was 16.4m B and 15.3m V. The amplitude of V350 Cep is larger than 4.7m B. The amplitude of brightening in near-IR region is about 1^m K during 6 years (1975-1981) (obtained by comparing results of Cohen and Schwartz (1983) and Strom et al. (1976)). The shape of the light curve of V350 Cep resembles that of FU Ori type star V1515 Cyg (Herbig, 1977). However, as was noted by Gyulbudaghian et al. (1978), the absolute magnitude of V350 Cep corresponds to the value of T Tau type stars. Cohen (1983) presents for V350 Cep (NGC 7129/IRS 1) L = 5.3 L_sun, i.e. the value of the absolute bolometric magnitude M_bol=+2.9m, while the FU Ori type objects in maximum have M_pg =-2.4m+-0.6m (Herbig, 1977). Spectral observations in July-Aug. 1978 by Magakyan and Amirkhanyan (1979) showed a classical T Tau type spectrum. Strong spectral variability was later observed by Magakyan (1983). In July 1981 the spectrum was T Tau type with strong emission lines (Cohen and Fuller, 1985). The Ca II H and K [FIGURE 1] Figure 1. Photographic (V) chart for V 350 Cep [FIGURE 2] Figure 2. B and V light curves of V350 Cep. Dots are our photographic data, crosses: photographic observations (Gyulbudaghian, Sarkisyan, 1978ab and Akhverdyan, Gyulbudaghian, 1978), triangle: mean photoelectric value by Berdnikov and Ibragimov (Shevchenko, Yakubov, 1989), square: CCD-photometry (Hartigan, Lada, 1985), symbols like letter "V": upper limits of brightness from our data. Table I The comparison star's sequence * B * V * B V A ----- 13.93 J 17.68 16.17 B 15.79 14.40 K 18.24 16.88 C 15.92 14.90 L 18.41 17.19 D 16.08 15.25 M 18.7 16.47 B 16.46 15.22 N 18.6 17.73 F 16.81 14.70 G 17.19 16.06 H 17.61 15.96 Table II Observations with 50/70/200 cm Maksutov telescope J.D.24... B J.D.24... B J.D 24... V 41241.217 18.6 47416.295 16.94 41577.460 18.1 41246.203 18.8 47418.301 17.07 41578.435 17.9 41247.330 (18.3 47683.444 16.90 46588.519 15.30 46087.207 (16.1 J.D.24... V 46590.499 15.48 46588.433 (16.1 41569.453 15.15 47417.250 15.77 46588.433 16.69 41570.373 17.85 47654.502 15.96 Observations with 80/120/240 cm Baldone Schmidt telescope J.D.24... H J.D.24... V 42666.413 (16.1 42666.368 16.55 42666.457 (16.1 42666.383 16.65 43377.471 17.06 43364.438 16.17 44512.290 15.84 Observations with 40/160 cm astrograph J.D. 24... B J.D. 24... B J.D. 24... B 45558.534 16.90 47032.501 16.96 47766.506 16.98 46646.514 16.47 47385.432 (16.5 47773.451 17.02 46652.482 16.46 47388.466 (16.5 47797.425 (16.5 46657.531 17.40 47395.373 16.84 47807.423 16.96 46685.404 16.45 47418.371 17.05 47836.230 16.69 46706.338 16.57 47422.423 16.93 47852.204 16.47 46712.315 16.70 47448.307 16.66 47861.151 16.36 46762.194 16.86 47471.278 (16.1 46768.177 17.13 47477.185 16.90 lines were in emission and broad shallow absorptions (Sp. type M2) were present in Oct. 1982 (op. cit.). Goodrich (1986) reports that the EW of H alpha emission line was equal to 71 Angstrom in July 1985. It would be interesting to search for periodic light variations in V350 Cep like those found in many T Tau type stars. The author is grateful to Dr. V.P. Goranskij for obtaining additional plates and help during the study and to Dr. A. Alksnis for estimating Baldone plates. A.YU. POGOSYANTS Sternberg State Astronomical Institute 13 Universitetskij Prospect, Moscow 119899, U.S.S.R. 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