Detection of 610-MHz radio emission from hot magnetic stars

P. Chandra, G. A. Wade, J. O. Sundqvist, D. Oberoi, J. H. Grunhut, A. Ud-Doula, V. Petit, D. H. Cohen, M. E. Oksala, A. David-Uraz

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Abstract

We have carried out a study of radio emission from a small sample of magnetic O- and Btype stars using the Giant Metrewave Radio Telescope, with the goal of investigating their magnetospheres at low frequencies. These are the lowest frequency radio measurements ever obtained of hot magnetic stars. The observations were taken at random rotational phases in the 1390 and the 610 MHz bands. Out of the eight stars, we detect five B-type stars in both the 1390 and the 610 MHz bands. The three O-type stars were observed only in the 1390 MHz band, and no detections were obtained. We explain this result as a consequence of free-free absorption by the free-flowing stellar wind exterior to the confined magnetosphere. We also study the variability of individual stars. One star - HD 133880 - exhibits remarkably strong and rapid variability of its low-frequency flux density. We discuss the possibility of this emission being coherent emission as reported for CU Vir by Trigilio et al.

Original languageEnglish (US)
Pages (from-to)1245-1253
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Volume452
Issue number2
DOIs
Publication statusPublished - Feb 11 2015

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All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Chandra, P., Wade, G. A., Sundqvist, J. O., Oberoi, D., Grunhut, J. H., Ud-Doula, A., ... David-Uraz, A. (2015). Detection of 610-MHz radio emission from hot magnetic stars. Monthly Notices of the Royal Astronomical Society, 452(2), 1245-1253. https://doi.org/10.1093/mnras/stv1378