Low-frequency GMRT observations of the magnetic Bp star HR Lup (HD 133880)

Samuel J. George$^{1,2}$, Ian R. Stevens$^{2}$

1 - Astrophysics Group, The Cavendish Laboratory, JJ Thomson Avenue, University of Cambridge, Cambridge, CB3 0HE, UK;
2 - Astrophysics and Space Research Group, School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK

We present radio observations of the magnetic chemically peculiar Bp star HR Lup (HD 133880) at 647 and 277 MHz with the GMRT. At both frequencies the source is not detected but we are able to determine upper limits to the emission. The 647 MHz limits are particularly useful, with a 5$sigma$ value of 0.45 mJy. Also, no large enhancements of the emission were seen. The non-detections, along with previously published higher frequency detections, provide evidence that an optically thick gyrosynchrotron model is the correct mechanism for the radio emission of HR Lup.

Reference: accepted for publication in the Bulletin of the Astronomical Society of India, to appear in the June issue; http://arxiv.org/abs/1206.1155
Status: Manuscript has been accepted

Weblink: http://arxiv.org/abs/1206.1155


Email: sgeorge@mrao.cam.ac.uk