A Search for Radio Emission from Nearby Exoplanets
Abstract
Since the discovery of the first extrasolar planet orbiting a main sequence star more than 20 years ago, the study of exoplanets has become a burgeoning field with more than 3300 confirmed extrasolar planets now known. A variety of techniques has been used to discover exoplanets orbiting main sequence stars and to deduce their properties: timing, radial velocities, direct imaging, microlensing, and transits in the optical/IR bands. Absent from this list so far is the detection of exoplanets at radio wavelengths, but not for lack of trying. Searches for radio emission from exoplanets predate their discovery (Winglee et al. 1986) and have continued sporadically to this day. The majority of searches for radio emission from exoplanets has searched for coherent radio emission. It is indeed the case that in our own solar system, all magnetized planets are powerful radio emitters, the likely emission mechanism being the cyclotron maser instability. The outstanding example is Jupiter, which emits 1010-1011 W at decameter wavelengths (frequencies <40 MHz). If there are Jupiter-like planets in other solar systems, many must surely emit CMI radiation. The emitted radiation could be orders of magnitude more intense than Jupiter’s if the interaction between the magnetized planet and the wind from the primary star is stronger than the Sun/Jupiter interaction - due, for example, to a more powerful wind and/or the planet being closer to the star.We have initiated a new search for radio emission from exoplanets, focusing on all known exoplanetary systems within 20 pc - more than 50 systems containing nearly 100 planets using the Jansky Very Large Array (JVLA) in three frequency bands: 1-2 GHz, 2-4 GHz, and 4-8 GHz with a target sensitivity of ~10 microJy. We have completed the 2-4 GHz survey and report our preliminary results, which include the detection of two systems. We discuss whether the emission is from a planet or from the star and the implications of our conclusions for habitability of exoplanets.
- Publication:
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American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017
- Bibcode:
- 2017AAS...22914635M