RT Journal Article T1 Emissions from the transition regions and coronae of three cool dwarf stars A1 Fernández Figueroa, María José A1 Castro Rubio, Elisa de A1 Rego Fernández, Manuel AB Ultraviolet emissions of τCet, δPav, and 61 Cyg A have been analysed to determine the structure of their outer atmospheres.Emission line fluxes are used to find the emission measure distributions. Using two boundary values of the electron pressure, models of the transition region have been derived. In the two models of τCet the net conductive flux is less than the radiation losses at all temperatures. However, for δPav and 61 Cyg A the model with the upper boundary value of the electron pressure has a temperature range where the radiative losses are less than the net conductive fluxes. Measured X-ray fluxes are used to test the coronal temperature values derived from the ultraviolet observations. PB EDP Sciencies SN 0004-6361 YR 1983 FD 1983 LK https://hdl.handle.net/20.500.14352/64990 UL https://hdl.handle.net/20.500.14352/64990 LA eng NO Ayres, T., Linsky, J.L.: 1980, Astrophys. J. 235, 76Ayres, T.R., Marstad, N.C., Linsky, J.L.: 1981, Astrophys. J. 247, 545Barnes, J.G., Evans, D.S.: 1976, Monthly Notices Roy. Astron. Soc. 174, 489Barnes, J.G., Evans, D.S., Parsons, S.B.: 1976, Monthly Notices Roy. Astron. Soc. 174, 503Bogges, A., Carr, F.A., Evans, D.C., Fischel , D., Freeman, H.R., Fuechsel, C.F., Klinglesmith, D.A., Krueger, V.L., Longanecker, G.W., Moore, J.V., Pyle, A.B., Rebar, F., Sizemore, K.O., Sparks, W., Underhill, A.B., Vitagliano, H.D., West, D.K., Macchetto, F., Fitton, B., Barker, P.J., Dunford, E., Gond­ halekar, P.M., Hall, J .E., Harrison, V.A.W., Oliver, M.B., Sandford, M.C.W., Vaughan, P.A., Ward, A.K., Anderson, B.E., Boksenberg, A., Coleman, C.I., Snijders, M.A.J., Wilson, R.: 1978, Nature 275, 372Bohlin, R.C., Holm, A.: 1980, IUE NASA Newsletter No. 10, p. 37Brown, A., Jordan, C.: 1981, Monthly Notices Roy. Astron. Soc. 196, 757Castro, E., Fernández Figueroa, M.J., Rego, M., Ponz, D.: 1981, Astron. Astrophys. 102, 207Dupree, A.K., Hartmann, L.: 1980, in Stellar Turbulence, IAU Coll. 51, eds. D. F. Gray and J. L. Linsky, Springer, Berlín, Heidelberg, New York, p. 279Fernández Figueroa, M.J., Castro, E., Rego, M.: 1982, ESA SP-176, p. 157Giacconi, R., Branduardi, G., Briel, U., Epstein, A., Frabricant, D., Feigelson, E., Forman, W., Gorenstein, P., Grindlay, J., Gursky, H., Harnden, F.R., Henry, J.P., Jones, C., Kellogg, E., Kock, D., Murray, S., Schreier, E., Seward, F., Tananbaum, H., Topka, K., Van Speybroeck, L., Holt, S.S., Becker, R.H., Boldt, E.A., Serlemitsos, P.J., Clark, G., Cañizares, C., Market, T., Novick, R., Helfand, D., Long, K.: 1979, Astrophys. J. 230, 540Haisch, B.M., Linsky, J.L.: 1976, Astrophys. J. 205, L 39 Hearnshaw, J.B.: 1974, Astron. Astrophys. 34, 263 Hearnshaw, J.B.: 1975, Astron. Astrophys . 38, 271Johnson, H.M.: 1981, Astrophys. J. 243, 234Johnson , H.L., Mitchell, R.I., Iriarte, D.: 1966, Comm. Lunar Planetary Lab. 4, 99Jordan, C.: 1969, Monthly Notices Roy. Astron. Soc. 142, 501Jordan, C.: 1980a, Higlights of Astronomy, Reidel, Dordrecht, Vol. 5, p. 533Jordan, C.: 1980b, Astron. Astrophys. 86, 355Jordan, C., Wilson , R.: 1971, Physics of the Solar Corona p. 211, ed. C.J. Macris, Reidel, DordrechtLinsky, J.L., Haisch, B.M.: 1979, Astrophys. J. 229, L 27Linsky, J.L., Worden, S.P., McClintock, W., Robertson, R.M.: 1979, Astrophys. J. Suppl. 41, 47Mullan, D.J.: 1976, Astrophys. J. 209, 171 Oinas, V.: 1977, Astron. Astrophys. 61, 17Raymond, J.C., Smith, B.W.: 1977, Astrophys. J. Suppl. 35, 419 Simon, T., Linsky, J.L., Stencel, R.: 1982, Astrophys. J. 257, 225 Vaiana, G.S., Cassinelli, J.P., Fabbiano, G., Giacconi, R., Golub, L., Gorenstein, P., Haisch, B.M., Harnden, F.R ., Johnson, H.M., Linsky, J.L., Maxson, C.W., Mewe, R., Rosner, R., Seward, F., Topka, K., Zwaan , C.: 1981, Astrophys. J. 245, 163Wilson, O.C., Bappu, M.K.V.: 1957, Astrophys. J. 125, 661Zirin, H.: 1976, Astrophys. J. 208, 414 NO © European Southern Observatory. We would like to thank an anonymous referee for useful comments. DS Docta Complutense RD 17 may 2024