COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 2229 Konkoly Observatory Budapest 1982 November 18 HU ISSN 0374-0676 MULTIPLE COMPONENTS IN THE Halpha PROFILE OF THE LUMINOUS SUPERGIANT HD 217476 The G-type supergiant HD 217476 (HR 8752) is one of the most luminous stars in our Galaxy, and curious behaviour has been reported at ultraviolet, optical and radio wavelengths (Sargent, 1965; Smolinski, 1971; Smolinski, Feldman and Higgs, 1977; Stickland and Harmer, 1978; Smolinski, Climenhaga, Funakawa and Fletcher, 1979; Lambert, Hinkle and Hall, 1981). Although this star has been extensively observed for more than a decade, the complex and variable nature of the spectrum is not well understood. During 1982 this high luminosity supergiant showed multiple components in Halpha and in the metallic lines. Some of these components were not observed in any of our previous spectra of this star obtained at the Dominion Astrophysical Observatory over a 13-year period since 1969. Only a brief description of these interesting features as observed during 1982 will be given in this paper, but a full discussion of their behaviour based on our 13 years of observations will be given in a separate paper which is presently in preparation. In Figure 1 are shown the profiles in the spectral region containing Halpha and the TiII line at lambda6559.6 for two spectra taken on May 4, 1982 and on September 27, 1982. The radial velocity information for the various components of these lines is given in Table I. [FIGURE 1] Figure 1: The Halpha region for HD217476 with dispersion 10 A/mm. The horizontal broken lines show the continuum levels of the spectra. The numbers give the radial velocities of the components. Note that the emission component with velocity -3 km/s appears in Halpha on September 27. Table I Radial Velocities for HD217476 in the Halpha Region Radial Velocity (km/s) Plate TiII Halpha Date No. A2 As A1 A2 A3 A2+A3 E1 E2 May 4,1982 14167 -102 -44 -131 -- -- -91 -47 -- Sept.27,1982 14402 -103 -53 -132 -101 -83 -96* -46 -3 Note *Best fit for the A2 and A3 components together. The components of particular interest are as follows. (1) There is a red emission component (E2) in Halpha with velocity = -3 km/s in addition to the red emission (E1) which is always present with velocity = -46 km/s. This -46 km/s emission component may be formed in the HII region surrounding the high luminosity star. The -3 km/s component varies in intensity and its origin is uncertain, but it may be associated with a binary nature and/or a pulsation of the star. (2) An absorption component (A1) appears in Halpha with velocity = -131 km/s where blue emission occurred in previous spectra in 1979. (3) Three absorption components (A1, A2, A3) appear in the Halpha profile on September 27th with velocities = -132 km/s (the component referred to in (2)), -101 km/s and -83 km/s, while only two components (A1 and a blend of A2 and A3) are seen in the May 4th profile with velocities -131 km/s and -91 km/s. The shape of the absorption part of the Halpha profile is similar to that observed by Luck and Lambert (1981) in the long period Cepheids X Cyg and SV Vul. (4) The TiII line at lambda6559.6 shows two components on May 4th, one (A2) with velocity -102 km/s is presumably formed in the expanding envelope, and the other (As), with velocity = -44 km/s is the stellar component. On September 27th, the pattern is similar, but the stellar component now has a velocity = -53 km/s. There is a possibility that the -102 km/s component is blended with a telluric H20 line. However, most of the absorption lines, and in particular the neutral Fe I lines, show this same pattern. More details and interpretation of the behaviour of this circumstellar envelope will be given in the paper which is presently in preparation. J. SMOLINSKI*, J.L. CLIMENHAGA and H. FUNAKAWA Department of Physics, University of Victoria, Victoria, B.C., Canada J.M. FLETCHER Dominion Astrophysical Observatory, Victoria, B.C., Canada References: Lambert, D.L., Hinkle, K.H., and Hall, D.N.B. 1981, Astrophys. J., 248, 638. [BIBCODE 1981ApJ...248..638L ] Luck, R.E. and Lambert, D.L. 1981, Astrophys. J., 245, 1018. [BIBCODE 1981ApJ...245.1018L ] Sargent, W.L.W. 1965, Observatory, 85, 33. [BIBCODE 1965Obs....85...33S ] Smolinski, J. 1971; in Colloquium on Supergiant Stars, ed. M. Hack, Osservatorio Astronomico di Trieste, Trieste, p. 68. [BIBCODE 1972css..conf...68S ] Smolinski, J., Climenhaga, J.L., Funakawa, H. and Fletcher, J.M. 1979, I.A.U. Circ. No. 3382. [BIBCODE 1979IAUC.3382....2S ] Smolinski, J., Feldman, P.A., and Higgs, L.A. 1977, Astr. Astrophys., 60, 277. [BIBCODE 1977A&A....60..277S ] Stickland, D.J. and Harmer, D.L. 1978, Astr. Astrophys., 70, L53. [BIBCODE 1978A&A....70L..53S ] * On leave from N. Copernicus Astronomical Center, Torun, Poland