A search for radio emission from exoplanets around evolved stars
Artikel i vetenskaplig tidskrift, 2018

The majority of searches for radio emission from exoplanets have to date focused on short period planets, i.e., the so-called hot Jupiter type planets. However, these planets are likely to be tidally locked to their host stars and may not generate sufficiently strong magnetic fields to emit electron cyclotron maser emission at the low frequencies used in observations (typically >= 150 MHz). In comparison, the large mass-loss rates of evolved stars could enable exoplanets at larger orbital distances to emit detectable radio emission. Here, we first show that the large ionized mass-loss rates of certain evolved stars relative to the solar value could make them detectable with the LOw Frequency ARray (LOFAR) at 150 MHz (lambda = 2 m), provided they have surface magnetic field strengths >50 G. We then report radio observations of three long period (>1 au) planets that orbit the evolved stars beta Gem, iota Dra, and beta UMi using LOFAR at 150 MHz. We do not detect radio emission from any system but place tight 3 sigma upper limits of 0.98, 0.87, and 0.57 mJy on the flux density at 150 MHz for beta Gem, iota Dra, and beta UMi, respectively. Despite our non-detections these stringent upper limits highlight the potential of LOFAR as a tool to search for exoplanetary radio emission at meter wavelengths.

planets and satellites: aurorae

radio continuum: planetary systems

surveys

planets and satellites: magnetic fields

stars: evolution

planets and satellites: detection

Författare

[Person f14ac06c-67e4-4a77-bd1f-c77a77e5c1dd not found]

[Person d8951555-e763-4f8a-b2f0-ef327b2d134e not found]

[Person 620ac39d-f3ba-4fd1-ac08-7e13258f4287 not found]

[Person 9ff13da4-7333-4035-9a8b-0eb912519b1a not found]

[Person 55ab0374-9d92-4526-aa0b-b12eb4c9ac08 not found]

[Person e6784a5a-9c00-4f9e-8524-53ee2d90614a not found]

[Person 8e8fe084-8fd1-4fcb-afe9-3b94129f0f0c not found]

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 612 A52

Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN)

Europeiska kommissionen (EU), 2014-05-01 -- 2019-04-30.

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fusion, plasma och rymdfysik

Den kondenserade materiens fysik

DOI

10.1051/0004-6361/201731965

Mer information

Senast uppdaterat

2018-06-14