Outstanding stellar microwave flares in 1986

O. B. Slee, G. J. Nelson, R. T. Stewart, A. E. Wright, D. L. Jauncey, Alan Vaughan, M. I. Large, John D. Bunton, W. L. Peters, S. G. Ryan

Research output: Contribution to journalArticlepeer-review


We describe bright microwave events that were first detected with the Parkes 64-m telescope at 8.4 or 22 GHz from six active-chromosphere stars. In some flares spectral data were obtained over a large frequency range from simultaneous measurements with the Parkes reflector (8.4 or 22 GHz), the Tidbinbilla interferometer (8.4 and 2.29 GHz), the Fleurs synthesis telescope (1.42 GHz) and the Molonglo Observatory synthesis telescope (0.843 GHz). Data on circular polarization were obtained from the Parkes observations at 8.4 GHz.

The stars were in a wide variety of evolutionary states, ranging from a single pre-main-sequence star (HD 36705), two RS CVn binaries (HD 127535, HD 128171), an Algol (HD 132742) and two apparently single K giants (HD 32918 and HD 196818). Their high brightness temperatures, positive spectral indices and low polarization are consistent with optically thick gyrosynchrotron emission from mildly relativistic electrons with average energies 0.5 to 3 MeV gyrating in inhomogeneous magnetic fields of 5 to 100 G.
Original languageEnglish
Pages (from-to)55-59
Number of pages5
JournalProceedings astronomical society of australia
Issue number1
Publication statusPublished - 1987

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