Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 1, 2013 | Published + Accepted Version
Journal Article Open

Looking for a Pulse: A Search for Rotationally Modulated Radio Emission from the Hot Jupiter, τ Boötis b


Hot Jupiters have been proposed as a likely population of low-frequency radio sources due to electron cyclotron maser emission of similar nature to that detected from the auroral regions of magnetized solar system planets. Such emission will likely be confined to specific ranges of orbital/rotational phase due to a narrowly beamed radiation pattern. We report on GMRT 150 MHz radio observations of the hot Jupiter τ Boötis b, consisting of 40 hr carefully scheduled to maximize coverage of the planet's 79.5 hr orbital/rotational period in an effort to detect such rotationally modulated emission. The resulting image is the deepest yet published at these frequencies and leads to a 3σ upper limit on the flux density from the planet of 1.2 mJy, two orders of magnitude lower than predictions derived from scaling laws based on solar system planetary radio emission. This represents the most stringent upper limits for both quiescent and rotationally modulated radio emission from a hot Jupiter yet achieved and suggests that either (1) the magnetic dipole moment of τ Boötis b is insufficient to generate the surface field strengths of >50 G required for detection at 150 MHz or (2) Earth lies outside the beaming pattern of the radio emission from the planet.

Additional Information

© 2013 American Astronomical Society. Received 2012 September 25; accepted 2012 November 1; published 2012 December 13. We thank the staff of the GMRT for their assistance with this observing program. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. Armagh Observatory is grant aided by the N. Ireland Department of Culture, Arts & Leisure. A.A. gratefully acknowledges the support of the Bulgarian National Science Fund (contract No. DDVU02/40/2010). J.G.D. wishes to thank the Leverhulme Trust for funding. A.G. acknowledges support from Science Foundation Ireland (grant No. 07/RFP/PHYF553).

Attached Files

Published - 0004-637X_762_1_34.pdf

Accepted Version - 1210.8259.pdf


Files (2.0 MB)
Name Size Download all
1.0 MB Preview Download
994.1 kB Preview Download

Additional details

August 22, 2023
October 23, 2023