A search for circularly polarized emission from young exoplanets
We report the results of a 154 MHz survey to search for emission from exoplanets located in the Upper Scorpius subgroup of the Sco Cen OB2 Association, the closest substantial region of recent star formation. This survey is different from previous efforts in that it is the first to target exoplan...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
Oxford University Press
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/69919 |
| Summary: | We report the results of a 154 MHz survey to search for emission from exoplanets located in
the Upper Scorpius subgroup of the Sco Cen OB2 Association, the closest substantial region
of recent star formation. This survey is different from previous efforts in that it is the first
to target exoplanets orbiting Myr-old stars. Young exoplanet systems are expected to be the
best candidates for radio detections given the higher magnetic field strengths predicted for
young planets as well as the stronger and more dense stellar wind expected for the host stars.
The radio emission from exoplanets is expected to be highly circularly polarized therefore we
restricted our search to the circular polarization images rather than the total intensity images.
We carried out two different search methods using this data. The first method was a targeted
search for exoplanet emission using catalogues of known stars and Hot Jupiters within the
Upper Scorpius field. The second search method was a blind search for highly circularly
polarized sources in the field and for sources identified only in our polarization images. Both
the blind and targeted search resulted in non-detections with typical 3σ flux density limits
of 4–235 mJy over time-scales of 1.87–1000 min. In particular, we place the first limits on
low-frequency emission from the Hot Jupiter systems WASP-17 b and K2-33 b. These are the
first results from a larger program to systematically search for low-frequency radio emission
from planets orbiting young stars. |
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