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Toward Solving the Mysteries of the Exotic Eclipsing Binary є Aurigae: Two Thousand years of Observations and Future Possibilities

Published online by Cambridge University Press:  12 April 2016

Edward F. Guinan  and
Laurence E. DeWarf
Edward F. Guinan
Affiliation:
Department of Astronomy & Astrophysics, Villanova University, Villanova, PA 19085, USA
Laurence E. DeWarf
Affiliation:
Department of Astronomy & Astrophysics, Villanova University, Villanova, PA 19085, USA

Abstract

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The long period (P = 27.1 yr) eclipsing binary є Aurigae (F0 Ia + disk?) is truly an exotic star. It has a deep eclipse that lasts for nearly two years. This eclipse arises as a huge, cool, flattened disk transits the F-supergiant star. Modeling of the eclipse observations shows that the disk has a radius as large as ∼ 9 AU. Infrared observations indicate that the disk is cool with temperatures between 450 − 1000 K. Yet there is evidence of significant FUV emission also originating from the disk.

At present, our knowledge of the mass and luminosity of the binary is still too uncertain to distinguish between two competing models of the system. The high mass model assumes that the F0 supergiant is a normal Pop. I star with a mass appropriate for its spectral type of M ∽ 15 M⊙. It is accompanied by a flattened disk companion with a slightly smaller mass. In this model the disk object is a young proto-stellar or protoplanetary disk. In the low mass model, the F0I star is assumed to be a bloated, old, solar mass post-AGB star. In this case the secondary object is an accretion disk with a mass of 4-5 M⊙. This disk is a remnant of postmain sequence mass transfer that occurred within the last few thousand years. In both models there are still problems explaining the object (or objects) at the center of the disk. Candidates include a pre-main sequence object, a black hole, or a close binary.

In this paper we review the properties of ϵ Aurigae and discuss the advances in our understanding of this enigmatic star from observations made since its last eclipse in 1982-1984. With new technologies and advanced instrumentation it is possible that the physical properties of this puzzling binary star will be found during the next decade. Once found, then ϵ Aurigae and its eclipses can be used as a laboratory for exploring (and testing) current astrophysical concepts and theories that include rapid stages of stellar evolution, binary star evolution, and the structure and dynamics of large disks.

Type
Research Article
Information
International Astronomical Union Colloquium , Volume 187: Exotic Stars as Challenges to Evolution , 2002 , pp. 121 - 142
Copyright
Copyright © Astronomical Society of the Pacific 2002

References

Allenhoff, W.J., Thum, C., & Wendker, H.J. 1994, A&A, 281, 161 Google Scholar
Backman, D.E., Beckfin, E.E., Cruikshank, D.P., Joyce, R.R., Simon, T., & Tokunaga, A. 1984, ApJ, 284, 799 CrossRefGoogle Scholar
Backman, D.E., Witteborn, P.C., & Gillett, F.C. 1992, ApJ, 385, 670 Google Scholar
Bailey, F. 1843, MmRAS, 13, 1 Google Scholar
Boehm, C., Ferluga, S., & Hack, M. 1984, A&A, 130, 419 Google Scholar
Bond, H.E., Carney, B.W., & Grauer, A.D. 1984, PASP, 96, 176 Google Scholar
Cameron, A.G.W. 1971, Nature, 229, 178 Google Scholar
Carroll, S.M., Guinan, E.F., McCook, G.P., & Donahue, R. 1990, ApJ, 367, 278 Google Scholar
Castelli, F. 1978, A&A, 69, 23 Google Scholar
Drilling, J.S., & Landolt, A.U. 2000, in Allen’s Astrophysical Quantities (4th edition), ed. Cox, A.N. (New York: Springer-Verlag), 389 Google Scholar
Eggleton, P.P., & Pringle, J.E. 1985, ApJ, 288, 275 Google Scholar
Ferluga, S. 1990, A&A, 238, 270 Google Scholar
Flammarion, C. 1882, Les Etoiles et les Curiosités du Ciel, Suppl. Astronomie Populaire (Paris: Marpon & Flammarion)Google Scholar
Fekel, F.C. Jr., 1981, ApJ, 246, 879 Google Scholar
Gonzalez, G., Lambert, D.L., Wallerstein, G., Rao, N.K., Smith, V.V., & McCarthy, J.K. 1998, ApJS, 114, 133 CrossRefGoogle Scholar
Gyldenkerne, K. 1970, Vistas Astron., 12, 199 Google Scholar
Hack, M. 1961, Mem. Soc. Astr. Ital., 32, 351 Google Scholar
Hartigan, P., Hartmann, L., Kenyon, S., Strom, S., & Skrutskie, M. 1990, ApJ, 354, L25 CrossRefGoogle Scholar
Heintz, W.D., & Cantor, B.A. 1994, PASP, 106, 363 CrossRefGoogle Scholar
Herbig, G.H., & Boyarchuk, A.A. 1968, ApJ, 153, 397 CrossRefGoogle Scholar
Hrivnak, B.J., & Milone, E.F. 1984, ApJ, 282, 748 Google Scholar
Hrivnak, B.J., Kwok, S., & Volk, K.M. 1989, ApJ, 346, 265 CrossRefGoogle Scholar
Huang, S.-S. 1965, ApJ, 141, 976 Google Scholar
Iben, I. 1967, ARA&A, 5, 571 Google Scholar
Iben, I. 1982, ApJ, 260, 821 Google Scholar
Kerber, F., Koppen, J., Roth, M., & Trager, S.C. 1999, A&A, 344, L79 Google Scholar
Knobel, E.B. 1917, Ulugh Beg’s Catalogue of Stars (Washington D.C.: The Carnegie Institution)Google Scholar
Kopal, Z. 1971, Ap&SS, 10, 332 Google Scholar
Kuiper, G.P., Struve, O., & Strömgren, B. 1937, ApJ, 86, 570 Google Scholar
Kumar, S. 1987, MNRAS, 225, 823 Google Scholar
Lamb, S.A., Iben, I.I., & Howard, W.M. 1976, ApJ, 207, 209 Google Scholar
Larson, R.B. 1978, in Protostars and Planets, ed. Gehreis, T. (Tucson: Univ. Arizona Press), 43 Google Scholar
Lawlor, T.M., & MacDonald, J. 2002, Ap&SS, 279, 123 Google Scholar
Lissauer, J.J., & Backman, D.E. 1984, ApJ, 286, L39 Google Scholar
Lissauer, J.J., Wolk, S.J., Griffith, C.A., & Backman, D.E. 1996, ApJ, 465, 371 Google Scholar
Morris, S.C. 1962, JRASC, 56, 210 Google Scholar
Nordgren, T.E., Sudol, J.J., & Mozurkewich, D. 2001, AJ, 122, 2707 Google Scholar
Osmer, P.S. 1972, ApJS, 24, 247 Google Scholar
Paresce, F., & Burrows, Ch. 1987, ApJ, 319, L23 Google Scholar
Parthasarathy, M., & Lambert, D.L. 1983, PASP, 95, 1012 Google Scholar
Pendleton, Y.J., & Black, D.C. 1983, AJ, 88, 1415 Google Scholar
Peters, C.H.F., & Knobel, E.B. 1915, Ptolemy’s Catalogue of Stars: A Revision of the Almagest (Washington D.C.: The Carnegie Institution)Google Scholar
Pringle, J.E. 1981, ARA&A, 19, 137 Google Scholar
Saito, M., & Kitamura, M. 1986, Ap&SS, 122, 387 Google Scholar
Schönbemer, D. 1983, ApJ, 272, 708 Google Scholar
Sheffer, Y., & Lambert, D.L. 1999, PASP, 111, 829 Google Scholar
Skrutskie, M.F., Dutkevich, D., Strom, S.E., Edwards, S., Strom, K.M., & Shure, M.A. 1990, AJ, 99, 1187 Google Scholar
Smith, B.A., & Terrile, R.J. 1984, Science, 226, 1421 Google Scholar
Snell, R.L, & Edwards, S. 1981, ApJS. 45, 121 Google Scholar
Stencel, R.E. 1985, The Recent Eclipse of Epsilon Aurigae, NASA Conf. Publ. 2384 Google Scholar
Strand, K.A. 1959, AJ, 64, 346 Google Scholar
Strom, K.M., Strom, S.E., Edwards, S., Cabrit, S., & Skrutskie, M. 1989a, AJ, 97, 1451 CrossRefGoogle Scholar
Strom, S.E., Edwards, S., & Strom, K.M. 1989b, in The Formation and Evolution of Planetary Systems, ed. Weaver, H.A. & Danly, L. (Cambridge: Cambridge University Press), 91 Google Scholar
Taranova, O.G., & Shenavrin, V.I. 2001, Astron. Lett., 27, 338 Google Scholar
Trimble, V.L., & Thorne, K.S. 1969, ApJ, 156, 1013 Google Scholar
van de Kamp, P. 1978, AJ, 83, 975 Google Scholar
Van Hamme, W., & Wilson, R.E. 1986, ApJ, 306, L33 Google Scholar
Webbink, R.F. 1985, in The 1982-84 Eclipse of Epsilon Aurigae, ed. Stencel, R. (Washington: NASA), 49 Google Scholar
Wilson, R.E. 1971, ApJ, 170, 529 Google Scholar
Wright, K.O. 1970, Vistas Astron., 12, 147 Google Scholar