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Leavitt Variables: The Brightest Cepheids Variables and their Implications for the Distance Scale

Published online by Cambridge University Press:  12 April 2016

Gerald R. Grieve ,
Barry F. Madore  and
Douglas L. Welch
Gerald R. Grieve
Affiliation:
Canadian Centre for Remote Sensing, Ottawa, Ontario
Barry F. Madore
Affiliation:
Canadian Centre for Remote Sensing, Ottawa, Ontario
Douglas L. Welch
Affiliation:
Canadian Centre for Remote Sensing, Ottawa, Ontario

Abstract

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Two low-amplitude variable supergiants in the Large Magellanic Cloud, S65-08 and S65-48 are each found to have periods of approximately 250 days. The cfptical data suggest that these stars are high-luminosity cepheid variables falling more than one magnitude brighter than any other known Cepheids in the LMC. Confirmation of the cepheid nature of these stars comes from their H-band magnitudes which place them accurately on a simple linear extrapolation of the narrower infrared Period-Luminosity relation. So it appears that the cepheid Period-Luminosity relation extends up to Mv ~ -8.5. To honour the astronomer who discovered the first of these highest-liminosity Cepheids, we have sub-classified the variables with log P > 1.8 as being “Leavitt variables”. As soon as these long-period variables are discovered in other external galaxies, reliable distances should be possible out to (m-M) ~30.

Type
Part III. Extragalactic Cepheids and the PL Relation
Information
International Astronomical Union Colloquium , Volume 82: Cepheids: Theory and Observations , 1985 , pp. 215 - 218
Copyright
Copyright © Cambridge University Press 1985

References

Ardeberg, A., Brune, J. P., Maurice, E., and Prevot, L. 1972, Astr. Ap. Suppl., 6, 249.Google Scholar
Berendzen, R., Hart, R., and Seeley, D. 1976, “Man Discovers the Galaxies”, (New York, Science History Publications).Google Scholar
Bruent, J.-P., Prevot, L., Maurice, E., and Muratorio, G. 1973, Astr. Ap. Suppl., 9, 447.Google Scholar
Cox, J. P. 1980, “Theory of Stellar Pulsation”, (Princeton, Princeton University Press).CrossRefGoogle Scholar
Eggen, O. J. 1983, A. J., 88, 1458.CrossRefGoogle Scholar
Feast, M. W. 1984, in I.A.U. Symposium #108, Structure and Evolution of the Magellanic Clouds, ed. van den Bergh, S. and de Boer, K., (Dordrecht, Reidel), p 157.CrossRefGoogle Scholar
Grieve, G. 1983, Unpublished Doctoral Thesis, University of Toronto.Google Scholar
Leavitt, H. 1907, Harvard Ann., 60, 87.Google Scholar
Lindblad, B. 1922, Ap. J., 55, 85.CrossRefGoogle Scholar
Madore, B. F. 1982, Ap. J., 253, 575.10.1086/159659CrossRefGoogle Scholar
Madore, B. F. 1983, Highlights in Astronomy, Vol 6, ed. West, R. M., Dordrecht, Reidel), p 217.Google Scholar
Madore, B. F. 1984, in I.A.U. Colloquium No. 82., Cepheid Variables: Theory and Obwervations, ed Madore, B. F., (Cambridge Univ. Press).Google Scholar
McGonegal, R., McLaren, R. A., McAlary, C. W., Madore, B. F. 1983, Ap. J. (Letters), 257, L33.Google Scholar
Morgan, W. W. and Keenan, P. C. 1973, Ann. Rev. Astr. Ap., 11, 29.10.1146/annurev.aa.11.090173.000333CrossRefGoogle Scholar
Sandage, A. 1984, (preprint).Google Scholar
Sandage, A. and Tammann, G. A. 1968, Ap. J., 151, 531.CrossRefGoogle Scholar
Schaltenbrand, R. and Tammann, G. A. 1970, Astr. Ap., 7, 289.Google Scholar
Strohmeier, W. 1972, Variable Stars, (New York, Pergamon Press)Google Scholar
Welch, D. L., Wieland, F., McAlary, C. W., McGonegal, R., Madore, B. F., McLaren, R. A., Neugebauer, G. 1984, Ap. J. Suppl., 54, 547.CrossRefGoogle Scholar