Abstract
CH giants, with Mv around −1 to 0.5 (refs 1,2), are stars which have the following well-known properties: (1) weak lines of iron-group elements2, (2) rich in carbon, exceptionally strong features of CH, moderately strong (depending on the surface temperature) C2 and CN (refs 1,2), (3) relatively strong lines of the s-process elements (especially Sr and Ba), and (4) halo-population kinematics3,4. CH giants are also found in globular clusters: ω Cen, M22 and M55 (refs, 5,6). Later, Bond7 discovered a group of field stars, called CH subgiants, with Mv from 2 to 4 (ref. 8). The four properties listed above are shared by the CH subgiants. We discuss here a possible CH subdwarf. First, we establish its subdwarf nature through photometry and proper motion, then we discuss spectroscopic data. Finally, we review how CH giants, CH subgiants and the CH subdwarf constitute a sequence of increasingly challenging cases for the stellar evolution theory.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Keenan, P. C. Astrophys. J. 96, 101–105 (1942).
Wallerstein, G. & Greenstein, J. L. Astrophys. J. 139, 1163–1179 (1964).
Bidelman, W. P. Vistas in Astronomy vol. 2 (ed. Beer, A.) 1428–1437 (Pergamon, Oxford, 1956).
MacDonnell, D. J., Frye, R. L. & Upgren, A. R. Astr. J. 77, 384–391 (1972).
McClure, R. D. & Norris, J. Astrophys. J. Lett. 217, L101–L104 (1977).
McClure, R. D. Mem. Soc. Astr. Italiano 50, 15 (1979).
Bond, H. E. Astrophys. J. 194, 95–107 (1974).
Sneden, C. & Bond, H. E. Astrophys. J. 204, 810–817 (1976).
Faber, S. M., Burstein, D., Tinsley, B. M. & King, I. R. Astr. J. 81, 45–52 (1976).
Chiu, L.-T. G. Astrophys J. Suppl. 44, 31–71 (1980).
Kron, R. G. & Chiu, L.-T. G. Publ. astr. Soc. Pacif. 93, 397–404 (1981).
Becker, W. & Fenkart, R. Photometric Catalogue for Stars in Selected Areas and Other Fields in the RGU-System Vol. 1 (Astronomical Institute of the University of Basel, 1976).
Becker, W. Z. Astrophys. 62, 54–79 (1965).
Buser, R. Astr. Astrophys. 62, 411–424 (1978).
Mannery, E. J. & Wallerstein, G. Astrophys. J. 75, 169–170 (1970).
Bidelman, W. P. & Keenan, P. C. Astrophys. J. 114, 473–476 (1951).
Clayton, D. D. Principles of Stellar Evolution and Nucleosynthesis (McGraw-Hill, NewYork, 1968).
Sweigart, A. V. Astr. Astrophys. 24, 459–464 (1973).
Sweigart, A. V. Astrophys. J. 189, 289–291 (1974).
Gingold, R. Astrophys. J. 193, 177–185 (1974).
Smith, J. A. & Demarque, P. Astr. Astrophys. 92, 163–166 (1980).
Demarque, P. & Mengel, J. G. Astrophys. J. 164, 317–330 (1971).
Thomas, H.-C. Z. Astrophys. 67, 420–455 (1967).
Paczynski, B. & Tremaine, S. D. Astrophys. J. 216, 57–60 (1977).
Larson, R. B. Publ. astr. Soc. Pacif. 77, 452–455 (1965).
Petersen, J. O. Astr. Astrophys. 19, 197–199 (1972).
Rood, R. T. Astrophys. J. 162, 939–946 (1970).
Thomas, H.-C. Astrophys. Space Sci. 6, 400–414 (1970).
McClure, R. D., Fletcher, J. M. & Nemec, J. M. Astrophys. J. Lett. 238, L35–L38 (1980).
Dahn, C. C., Liebert, J., Kron, R. G., Spinrad, H. & Hintzen, P. M. Astrophys. J. 216, 757–766 (1977).
Liebert, J. Astrophys. J. Lett. 204, L39–L97 (1976).
Liebert, J., Dahn, C. C., Gresham, M. & Strittmatter, P. A. Astrophys. J. 233, 226–238 (1979).
Steinlin, U. W. Z. Astrophys. 69, 276–295 (1968).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
George Chiu, LT., Kron, R. A possible CH subdwarf. Nature 299, 702–704 (1982). https://doi.org/10.1038/299702a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/299702a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.