Abstract
A highly variable point X-ray source, first seen by the Einstein IPC, has been positioned with the EXOSAT CMA and identified with a bright (V = 8.5) K0 star. Although in the direction of the southern half of the Cygnus Loop, this star is almost certainly a foreground object and typical of other active cool stars that are related to RS CVn systems.
An EXOSAT program to study T Tauri stars failed to detect T Tau itself. However, a strong X-ray source was observed 15′ from T Tau, which in its turn had not been seen by Einstein. This new source has been identified with a hitherto unstudied 13 mag star which is likely to be a dMe flare star.
The young star cluster NGC 2264 was observed with the EXOSAT CMA in an attempt to identify the sources found during an Einstein IPC study of S Mon. Apart from S Mon itself, only UV-bright objects were seen, but several of these are considered likely counterparts of the Einstein sources.
Similar content being viewed by others
References
Charles, P.A., 1983, IAU Colloquium 71, p415, Byrne & Rodono (eds)
Charles, P.A., Kahn, S. & McKee, C.F., 1984 Ap.J. (submitted)
Feigelson, E.D. & DeCampli, W.M., 1981 Ap.J. 243, L89
Haisch, B.M., 1983, IAU Colloquium 71, p255, Byrne & Rodono (eds)
Ku, W.H.M., Righini-Cohen, G. & Simon, M., 1982 Science 215, 61
Ku, W.H.M., Kahn, S.M., Pisarski, R. & Long, K., 1984 Ap.J. 278, 615
Raymond, J.C. & Smith, B.W., 1977 Ap.J.Suppl. 35, 419
Simon, T., Cash, W. & Snow, T.P., 1984 Ap.J. (submitted)
Stern, R.A., Nousek, J.A., Nugent, J.J., Agrawal, P.C., Riegler, G.R., Rosenthal, A., Pravdo, S.H. & Garmire, G.P., 1981 Ap.J., 251, L105.
Walker, M.F., 1956, Ap.J.Suppl. 2, 365
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Charles, P.A., Corbet, R.H.D., Mukai, K. et al. EXOSAT observations of active stellar coronae in the Cygnus Loop, T Tau & NGC 2264 regions. Space Sci Rev 40, 73–78 (1985). https://doi.org/10.1007/BF00212869
Issue Date:
DOI: https://doi.org/10.1007/BF00212869