The search for radio emission from the exoplanetary systems 55 Cancri, υ Andromedae, and τ Boötis using LOFAR beam-formed observations
| Autor: | Joseph Lazio, J. Emilio Enriquez, Jake D. Turner, Laurent Lamy, Ray Jayawardhana, Jean-Mathias Grießmeier, Jonathan D. Nichols, Julien N. Girard, Baptiste Cecconi, Philippe Zarka, Imke de Pater |
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| Přispěvatelé: | Cornell University [New York], Department of Astronomy [Charlottesville], University of Virginia [Charlottesville], Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Rhodes University, Grahamstown, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of Leicester, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Virginia |
| Rok vydání: | 2021 |
| Předmět: |
planets and satellites
Astronomy Astrophysics::High Energy Astrophysical Phenomena Context (language use) Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics aurorae -planets and satellites 01 natural sciences law.invention Jupiter gaseous planets Planet law 0103 physical sciences Maser 010303 astronomy & astrophysics magnetic fields -radio continuum Physics Atmospheric escape [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] 010308 nuclear & particles physics Astronomy and Astrophysics LOFAR Planetary system Exoplanet Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science [SDU]Sciences of the Universe [physics] planetary systems -magnetic fieldsplanet-star interactions -planets and satellites Experimental High Energy Physics Astrophysics::Earth and Planetary Astrophysics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | Astronomy & Astrophysics, 645, pp. 1-28 Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 645, pp.A59. ⟨10.1051/0004-6361/201937201⟩ Epsc Abstracts, 15 Astronomy & Astrophysics, 645, 1-28 15th Europlanet Science Congress 2021 Europlanet Science Congress 2021 Europlanet Science Congress 2021, Sep 2021, Virtual Meeting, France. 14 pp., ⟨10.5194/epsc2021-430⟩ Astronomy and Astrophysics-A&A, 2021, 645, pp.A59. ⟨10.1051/0004-6361/201937201⟩ Astronomy & Astrophysics |
| ISSN: | 0004-6361 1432-0746 |
| Popis: | Observing planetary auroral radio emission is the most promising method to detect exoplanetary magnetic fields, the knowledge of which will provide valuable insights into the planet's interior structure, atmospheric escape, and habitability. We present LOFAR-LBA circularly polarized beamformed observations of the exoplanetary systems 55 Cancri, $\upsilon$ Andromedae, and $\tau$ Bo\"{o}tis. We tentatively detect circularly polarized bursty emission from the $\tau$ Bo\"{o}tis system in the range 14-21 MHz with a flux density of $\sim$890 mJy and with a significance of $\sim$3$\sigma$. For this detection, no signal is seen in the OFF-beams, and we do not find any potential causes which might cause false positives. We also tentatively detect slowly variable circularly polarized emission from $\tau$ Bo\"{o}tis in the range 21-30 MHz with a flux density of $\sim$400 mJy and with a statistical significance of $>$8$\sigma$. The slow emission is structured in the time-frequency plane and shows an excess in the ON-beam with respect to the two simultaneous OFF-beams. Close examination casts some doubts on the reality of the slowly varying signal. We discuss in detail all the arguments for and against an actual detection. Furthermore, a $\sim$2$\sigma$ marginal signal is found from the $\upsilon$ Andromedae system and no signal is detected from the 55 Cancri system. Assuming the detected signals are real, we discuss their potential origin. Their source probably is the $\tau$ Bootis planetary system, and a possible explanation is radio emission from the exoplanet $\tau$ Bootis b via the cyclotron maser mechanism. Assuming a planetary origin, we derived limits for the planetary polar surface magnetic field strength, finding values compatible with theoretical predictions. Further low-frequency observations are required to confirm this possible first detection of an exoplanetary radio signal. [Abridged] Comment: Accepted for publication in A&A (Oct. 22, 2020). 29 pages (15 pgs main text), 17 figures, 8 tables, 10 appendices |
| Databáze: | OpenAIRE |
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