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Line-Profiles of F Supergiant Stars as Candidates of Proto-Planetary Nebulae

Published online by Cambridge University Press:  12 April 2016

S. Tamura
Affiliation:
Astronomical Institute, Tohoku University, Aobayama, Sendai 989, Japan
M. Takeuti
Affiliation:
Astronomical Institute, Tohoku University, Aobayama, Sendai 989, Japan
J. Zalewski
Affiliation:
Astronomical Institute, Tohoku University, Aobayama, Sendai 989, Japan

Extract

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In this report the results of spectroscopic observations on selected F supergiant stars as the candidates of proto-planetary nebulae (PPNs) are presented. Volk and Kwok(1989) selected nearly one hundred new candidates of PPNs based upon the scenario on the evolution of them. They summarized four classes of stars which should be the PPNs and are described in various papers. These are (i) High galactic latitude supergiants, (ii) Nonvariable OH/IR stars, (iii) Low color temperature infrared objects, and (iv) R. CrB. In order to examine the extended envelope of the PPNs we have started our project to obtain the Hα profile which should give us some clue to the structure of the envelope. We are mainly concerned with F supergiant stars. Our sample objects are mostly classified as pulsating or semiregular variables.

Type
II. Observational Facts
Copyright
Copyright © Kluwer 1993

References

Luck, R.E. and Bond, H.E.: 1984, Astrophysical Journal 279, 729.Google Scholar
Tamura, S. and Takeuti, M.: 1991, IAU Inform. Bull. Variable Stars. No. 3561.Google Scholar
Tamura, S., Takeuti, M.. and Zalewski, J.: 1992, Sci. Rep. Tôhoku Univ. Ser. 8, 13.Google Scholar
Volk, K.M. and Kwok, S.: 1989, Astrophysical Journal 342, 345.Google Scholar