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Radio Emission from Red-Giant Hot JupitersWhen planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such "Red-Giant Hot Jupiters" (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.
Document ID
20160006717
Document Type
Reprint (Version printed in journal)
Authors
Fujii, Yuka (Tokyo Inst. of Tech. Tokyo, Japan)
Spiegel, David S. (Analytics and Algorithms San Francisco, CA, United States)
Mroczkowski, Tony (Naval Research Lab. Washington, DC, United States)
Nordhaus, Jason (Rochester Inst. of Tech. Rochester, NY, United States)
Zimmerman, Neil T. (Space Telescope Science Inst. Baltimore, MD, United States)
Parsons, Aaron R. (California Univ. Berkeley, CA, United States)
Mirbabayi, Mehrdad (Institute for Advanced Study Princeton, NJ, United States)
Madhusudhan, Nikku (Cambridge Univ. Cambridge, United Kingdom)
Date Acquired
May 31, 2016
Publication Date
March 30, 2016
Publication Information
Publication: The Astrophysical Journal
Volume: 820
Issue: 2
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
GSFC-E-DAA-TN32152
Funding Number(s)
CONTRACT_GRANT: NNH15CO48B
CONTRACT_GRANT: NSF-1440343
CONTRACT_GRANT: NSF-1352519
CONTRACT_GRANT: NSF-AST-1102738
CONTRACT_GRANT: HST AR-12146.04-A
WBS: WBS 811073.02.10.03.10
CONTRACT_GRANT: Grant-in-Aid No. 25887024
Distribution Limits
Public
Copyright
Other
Keywords
stellar winds
distance
magnitude
brightness
red giant stars
Jupiter (planet)
main sequence stars