Follow-up LOFAR observations of the $\tau$ Boötis exoplanetary system

Abstract

Context. Observing the radio emission from exoplanets is among the most promising methods to detect their magnetic fields and a measurement of an exoplanetary magnetic field will help constrain the planet's interior structure, star-planet interactions, atmospheric escape and dynamics, and habitability. Recently, circularly polarized bursty and slow emission from the $\tau$ Boötis ($\tau$ Boo) exoplanetary system was tentatively detected using LOFAR (LOW-Frequency ARray) beamformed observations. If confirmed, this detection will be a major contribution to exoplanet science. However, follow-up observations are required to confirm this detection. Aims. Here, we present such follow-up observations of the $\tau$ Boo system using LOFAR. These observations cover 70$\%$ of the orbital period of $\tau$ Boo b including the orbital phases of the previous tentative detections. Methods. We used the BOREALIS pipeline to mitigate radio frequency interference and to search for bursty and slowing varying radio signals. BOREALIS was previously used to find the tentative radio signals from $\tau$ Boo. Results. Our new observations do not show any signs of bursty or slow emission from the $\tau$ Boötis exoplanetary system. Conclusions. The cause for our non-detection is currently degenerate. It is possible that the tentative radio signals were an unknown instrumental systematic or that we are observing variability in the planetary radio emission due to changes in its host star. More radio data (preferably multi-site) and ancillary observations (e.g. magnetic maps) are required to further investigate the potential radio emission from the $\tau$ Boötis exoplanetary system.

9 pages, 5 figures, 2 tables. Accepted for publication in A&A (May 02, 2024). Updated with referee comments

References in corpus (34)

• The effect of red noise on planetary transit detection
• Predicting low-frequency radio fluxes of known extrasolar planets
• Magnetically controlled mass loss from extrasolar planets in close orbits
• Magnetic Effects in Hot Jupiter Atmospheres
• On the environment surrounding close-in exoplanets
• The search for radio emission from the exoplanetary systems 55 Cancri, $\upsilon$ Andromedae, and $\tau$ Boötis using LOFAR beam-formed observations
• The population of M dwarfs observed at low radio frequencies
• Radio emission from exoplanets: the role of the stellar coronal density and magnetic field strength
• GMRT Low Frequency Observations of Extrasolar Planetary Systems
• Magnetospheric Emissions from the Planet Orbiting tau Boo: A Multi-Epoch Search
• Monitoring the radio emission of Proxima Centauri
• Coherent radio bursts from known M-dwarf planet host YZ Ceti
• How Expanded Ionospheres of Hot Jupiters Can Prevent Escape of Radio Emission Generated by the Cyclotron Maser Instability
• Limits on low frequency radio emission from southern exoplanets with the Murchison Widefield Array
• Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope
• MOVES II. Tuning in to the radio environment of HD189733b
• A search for circularly polarised emission from young exoplanets
• The CARMENES search for exoplanets around M dwarfs. A long-period planet around GJ 1151 measured with CARMENES and HARPS-N data
• Can we detect aurora in exoplanets orbiting M dwarfs?
• Radio Observations of HD80606 Near Planetary Periastron: II. LOFAR Low Band Antenna Observations at 30-78 MHz
• MOVES V. Modelling star-planet magnetic interactions of HD 189733
• Radio-Loud Exoplanet-Exomoon Survey (RLEES): GMRT Search for Electron Cyclotron Maser Emission
• The Rise of ROME. I. A Multiwavelength Analysis of the Star-Planet Interaction in the HD 189733 System
• In search of radio emission from exoplanets: GMRT observations of the binary system HD~41004
• Magnetospheres of Terrestrial Exoplanets and Exomoons: Implications for Habitability and Detection
• uGMRT observations of the hot-Saturn WASP 69b: Radio-Loud Exoplanet-Exomoon Survey II (RLEES II)
• The Linkage between the Core Mass and the Magnetic Field of an Extrasolar Giant Planet from Future Radio Observations
• Shallowness of circulation in hot Jupiters -- Advancing the Ohmic dissipation model
• Star-Planet Interactions in the Radio Domain: Prospect for Their Detection
• Space environment and magnetospheric Poynting fluxes of the exoplanet $\tau$ Boötis b
• Non-thermal emission from the interaction of magnetized exoplanets with the wind of their host star
• Search for radio emission from the exoplanets Qatar-1b and WASP-80b near 150 MHz using the Giant Metrewave Radio Telescope
• ROME III. The Arecibo Search for Star-Planet Interactions at 5 GHz
• Follow-up radio observations of the $\tau$ Boötis exoplanetary system: Preliminary results from NenuFAR

Cited by in corpus (6)

• Star-Planet Interactions: A Computational View
• Unravelling sub-stellar magnetospheres
• Inflated hot Jupiters: Inferring average atmospheric velocity via Ohmic models coupled with internal dynamo evolution
• Magnetic field strengths of hot giant exoplanets consistent with Solar System values
• Radio prospects of extrasolar aurorae polaris as a probe of planetary magnetism
• Upper Limits on Planet-Induced GHz Radio Emission from Inactive M Dwarfs