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Rosat Observations of Stellar Flares

Published online by Cambridge University Press:  12 April 2016

J. H. M. M. Schmitt*
Affiliation:
Max-Planck-Institut für Extraterrestrische Physik, D-85740 Garching bei München, Germany

Abstract

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X-ray observations of stellar flares obtained during the ROSAT all-sky survey as well as in the ROSAT pointing program are discussed. The ROSAT all-sky survey allowed—for the first time—an unbiased search for stellar flares among all types of stars. A fundamentally new result obtained is that flares can occur on all types of late-type stars, thus supporting the view that the X-ray emission from these stars is controlled by magnetic processes. Long-duration flares can be studied with the all-sky survey data particularly well, and an especially well-observed long-duration flare event on the flare star EV Lacertae is presented and discussed in detail. Finally, the issue of time variability on the shortest detectable timescales and the question of microflaring is discussed using ROSAT data from a pointed observation of UV Ceti.

Subject headings: stars: coronae — stars: flare — stars: late-type — X-rays: stars

Type
Stars
Copyright
Copyright © The American Astronomical Society 1994

References

Ambruster, C., Snyder, W.A., & Woods, K.S. 1984, ApJ, 284, 270 CrossRefGoogle Scholar
Barstow, M.A., Bromage, G.E., Pankiewicz, G.S., Gonzalez-Riestra, R., Denby, M., & Pye, J.P. 1992, Nature, 353, 635 CrossRefGoogle Scholar
Bromage, G.E., et al. 1992, in ASP Conf. Ser. 26, 7th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, ed. Giampapa, M.S. & Bookbinder, J.A. (San Francisco: ASP), 80 Google Scholar
Butler, J.L., Rodonò, M., Foing, B.H., & Haisch, B.M. 1986, Nature, 321, 679 Google Scholar
deJager, C., et al. 1986, A&A, 156, 95 Google Scholar
Doyle, J., et al. 1991, MNRAS, 248, 503 Google Scholar
Fleming, T.A., Giampapa, M.S., Schmitt, J.H.M.M., & Bookbinder, J.A. 1993, ApJ, 410, 387 Google Scholar
Haisch, B.M. 1983, in Activity in Red Dwarf Stars, ed. Byrne, P.B. & Rodonò, M. (Astrophysics and Space Science Library, 102), 255 Google Scholar
Haisch, B.M., Linsky, J.L., Bornmann, P.L., Antiochos, S.K., Golub, L., & Vaiana, G.S. 1983, ApJ, 267, 280 CrossRefGoogle Scholar
Haisch, B.M., Strong, K.T., & Rodonò, M. 1991, ARA&A, 29, 275 Google Scholar
Kopp, R.A., & Poletto, G. 1984, Sol. Phys., 93, 351 CrossRefGoogle Scholar
Kürster, M., & Schmitt, J.H.M.M. 1994, in preparationGoogle Scholar
Linsky, J.L. 1985, Sol. Phys., 100, 333 CrossRefGoogle Scholar
Moore, R., et al. 1980, in Solar Flares, ed. Sturrock, P.A. (Boulder: Colorado Associated Univ. Press)Google Scholar
Pallavicini, R., Stella, L., & Tagliaferri, G. 1990a, A&A, 228, 443 Google Scholar
Pallavicini, R., Tagliaferri, G., Pollock, A.M.T., Schmitt, J.H.M.M., & Rosso, C. 1990b, A&A, 227, 483 Google Scholar
Pettersen, B. 1983, in Activity in Red Dwarf Stars, ed. Byrne, P.B. & Rodonò, M. (Astrophysics and Space Science Library, 102), 17 Google Scholar
Poletto, G., Pallavicini, R., & Kopp, R.A. 1989, A&A, 201, 93 Google Scholar
Press, W.H., & Schechter, P. 1974, ApJ, 193, 437 Google Scholar
Rieger, E. 1993, private communicationGoogle Scholar
Saar, S.H. 1988, ApJ, 324, 141 Google Scholar
Schmitt, J.H.M.M., Coltura, A., Sciortino, S., Vaiana, G.S., Harnden, F.R. Jr., & Rosner, R. 1990, ApJ, 365, 307 CrossRefGoogle Scholar
Schmitt, J.H.M.M., & Rosso, C. 1988, A&A, 191, 99 Google Scholar
Schmitt, J.H.M.M., Haisch, B.M., & Barwig, H. 1993a, ApJ, in pressGoogle Scholar
Schmitt, J.H.M.M., Zinnecker, H., Cruddace, R., & Harnden, F.R. Jr., 1993b, ApJ, 402, L13 Google Scholar
Serio, S., Peres, G., Vaiana, G.S., Golub, L., & Rosner, R. 1981, ApJ, 243, 288 CrossRefGoogle Scholar
Stern, R.A., et al. 1992, ApJ, 391, 760 Google Scholar
Tovmasyan, G.M., & Zalinyan, V.P. 1988, Astrofizika, 28, 131 Google Scholar
Tsuru, T., et al. 1989, PASJ, 41, 679 Google Scholar
van den Oord, G.H.J., & Mewe, R. 1989, A&A, 213, 245 Google Scholar
van den Oord, G.H.J., Mewe, R., & Brinkman, A.C. 1989, A&A, 205, 181 Google Scholar