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Spectroscopic Measurements of Stellar Rotation

Published online by Cambridge University Press:  30 March 2016

Dainis Dravins*
Affiliation:
Lund Observatory Box 43 S-221 00 Lund Sweden

Extract

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This section title is identical to that of the first paper where the broadening of absorption lines in response to stellar rotation was discussed: Abney (1877).

More accurate measurements now reveal also the details of stellar line shapes, making it possible to segregate the signatures of rotational and other broadening mechanisms: e.g. Gray (1992) and Smith & Gray (1976). To determine the rotation, fits can be made to line profiles (e.g. Anders et al., 1993), to their Fourier transforms (e.g. Dravins et al. 1990;Smith & Gray 1976), or to extended spectral regions (e.g. Kurucz et al. 1977).

This review, however, concerns issues for [single-epoch] spectroscopic observations only, no temporal aspect will be discussed.

What is observed is a rotationally broadened profile, the accuracy begins to get limited by the incomplete physical understanding of stellarline profiles and of the nature of stellar rotation. In order to disentangle the rotational broadening from other effects, one needs to know the ‘intrinsic’ (i.e. rotationally unbroadened) profile of the non-rotating star. How does this profile change with latitude and longitude across the stellar disk? What effects besides rotation are broadening the lines? What about mass loss, radial pulsation, non-radial oscillations, magnetic fields, spots, etc.? And the star might not even rotate as a rigid body, but perhaps differentially with respect to latitude and/or atmospheric height. All this has to be deduced from the often blended lines in complex spectra.

Type
II. Joint Discussions
Copyright
Copyright © Kluwer 1995

References

Abney, W.W.: 1877, MNRAS 37, 278 Google Scholar
Aerts, C., Waelkens, C.: 1993, A&A 273, 135 Google Scholar
Anders, G.J., Jeffries, R.D., Kellett, B.J., Coates, D.W.: 1993, MNRAS 265, 941 Google Scholar
Bruning, D.H.: 1981, ApJ 248, 274 Google Scholar
Carpenter, K.G., Slettebak, A., Sonneborn, G.: 1984, ApJ 286, 741 Google Scholar
Dravins, D.: 1994, in Sterken, C., Groot, M.de, eds. The Impact of Long-Term Monitoring in Variable Star Research, Kluwer, p. 269 Google Scholar
Dravins, D., Lindegren, L., Torkelsson, U.: 1990, A&A 237, 137 Google Scholar
Dravins, D., Nordlund, Å.: 1990, A&A 228, 203 Google Scholar
Gray, D.F.: 1977a, ApJ 211, 198 Google Scholar
Gray, D.F.: 1977b, ApJ 218, 530 Google Scholar
Gray, D.F.: 1982, ApJ 258, 201 Google Scholar
Gray, D.F.: 1988, in de Strobel, G. Cayrel & Spite, M., eds. The Impact of Very High S/N Spectroscopyon Stellar Physics, IAU Symp. 132, 185 CrossRefGoogle Scholar
Gray, D.F.: 1992, The Observation and Analysis of Stellar Photospheres, 2:nd ed., Cambridge Univ. Press Google Scholar
Gulliver, A.F., Hill, G., Adelman, S.J.: 1994, ApJ 429, L81 Google Scholar
Holweger, H., Steffen, M., Gigas, D.: 1986, A&A 163, 333 Google Scholar
Koester, D., Herrero, A.: 1988, ApJ 332, 910 CrossRefGoogle Scholar
Kurucz, R.L., Furenlid, I.: 1979, Sample Spectral Atlas for Sirius, Smithsonian Astrophys. Obs. Spec. Rep. 387 Google Scholar
Kurucz, R.L., Traub, W.A., Carleton, N.P., Lester, L.B.: 1977, 217, 771 Google Scholar
Marcy, G.W., Chen, G.H.: 1992, ApJ 390, 550 Google Scholar
Pikalov, K.N.: 1993, Kin.Phys.Cel.Bodies 9, 29 = Kin. Fiz. Nebesn. Tel 9, 37Google Scholar
Piskunov, N.E. Tuominen, I., Vilhu, O.: 1990, A&A 230, 363 Google Scholar
Ruusalepp, M.: 1982, in Jaschek, M., Groth, H.G., eds, Be Stars, IAU symp. 98, p.303 CrossRefGoogle Scholar
Smith, M.A., Gray, D.F.: 1976, PASP 88, 809 Google Scholar
Smith, M.A., Huang, Y-R., Livingston, W.: 1987, PASP 98, 297 Google Scholar
Soderblom, D.R.: 1982, ApJ 263, 239 Google Scholar