Radio Emission from Red-Giant Hot Jupiters

Abstract

When 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.

arXiv commentpublished in ApJ, corrected typo in abstract

References in corpus (44)

• LOFAR: The LOw-Frequency ARray
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits
• The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets
• The Theory of Brown Dwarfs and Extrasolar Giant Planets
• One or more bound planets per Milky Way star from microlensing observations
• On the Luminosity of Young Jupiters
• The Precision Array for Probing the Epoch of Reionization: 8 Station Results
• An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars
• Spectral and Photometric Diagnostics of Giant Planet Formation Scenarios
• What Next-Generation 21 cm Power Spectrum Measurements Can Teach Us About the Epoch of Reionization
• A New Version of Reimers' law of Mass Loss Based on a Physical Approach
• Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs
• Resolving the Radio Source Background: Deeper Understanding Through Confusion
• Models of circumstellar molecular radio line emission: Mass loss rates for a sample of bright carbon stars
• A Sensitivity and Array-Configuration Study for Measuring the Power Spectrum of 21cm Emission from Reionization
• A magnetic field evolution scenario for brown dwarfs and giant planets
• Predicting low-frequency radio fluxes of known extrasolar planets
• On the Orbits of Low-mass Companions to White Dwarfs and the Fates of the Known Exoplanets
• Planet Engulfment by ~1.5-3 Solar-Mass Red Giants
• Tides and Tidal Engulfment in Post-Main Sequence Binaries: Period Gaps for Planets and Brown Dwarfs Around White Dwarfs
• Spectral Index of the Diffuse Radio Background Measured From 100 to 200 MHz
• Magnetospheric Radio Emission from Extrasolar Giant Planets: The Role of the Host Stars
• The Magnetic Fields at the Surface of Active Single G-K Giants
• Hint of 150 MHz radio emission from the Neptune-mass extrasolar transiting planet HAT-P-11b
• Radio emission from exoplanets: the role of the stellar coronal density and magnetic field strength
• Thermal Processes Governing Hot-Jupiter Radii
• Secondary radio eclipse of the transiting planet HD 189733 b: an upper limit at 307-347 MHz
• GMRT Low Frequency Observations of Extrasolar Planetary Systems
• Structured Red Giant Winds with Magnetized Hot Bubbles and the Corona/Cool Wind Dividing Line
• A critical test of empirical mass loss formulae applied to individual giants and supergiants
• Detection of Exomoons Through Observation of Radio Emissions
• Looking for a Pulse: A search for Rotationally Modulated Radio Emission from the Hot Jupiter, Tau Bootis b
• A wide-band, active antenna system for long wavelength radio astronomy
• Limits on low frequency radio emission from southern exoplanets with the Murchison Widefield Array
• Jupiter will become a hot Jupiter: Consequences of Post-Main-Sequence Stellar Evolution on Gas Giant Planets
• Degree of Polarization and Source Counts of Faint Radio Sources from Stacking Polarized Intensity
• Direct detection of a magnetic field in the photosphere of the single M giant EK Boo: How common is magnetic activity among M giants?
• Magnetic field structure in single late-type giants: Beta Ceti in 2010 - 2012
• A stringent upper limit to 18cm radio emission from the extrasolar planet system tau Bootis
• Magnetic field and convection in the cool supergiant Betelgeuse
• Radio Emissions from Substellar Companions of Evolved Cool Stars
• Multi-wavelength Radio Continuum Emission Studies of Dust-free Red Giants
• Binary Evolution Leads to Two Populations of White Dwarf Companions

Cited by in corpus (11)

• The search for radio emission from the exoplanetary systems 55 Cancri, $\upsilon$ Andromedae, and $\tau$ Boötis using LOFAR beam-formed observations
• How Expanded Ionospheres of Hot Jupiters Can Prevent Escape of Radio Emission Generated by the Cyclotron Maser Instability
• The detectability of radio emission from exoplanets
• A search for long-timescale, low-frequency radio transients
• Science with the Murchison Widefield Array: Phase I Results and Phase II Opportunities
• A search for radio emission from exoplanets around evolved stars
• Survivability of radio-loud planetary cores orbiting white dwarfs
• Follow-up LOFAR observations of the $\tau$ Boötis exoplanetary system
• Size and strength of self-excited dynamos in Jupiter-like extrasolar planets
• The Linkage between the Core Mass and the Magnetic Field of an Extrasolar Giant Planet from Future Radio Observations
• Microlensed Radio Emission from Exoplanets