Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21542115l&link_type=abstract
American Astronomical Society, AAS Meeting #215, #421.15; Bulletin of the American Astronomical Society, Vol. 42, p.288
Astronomy and Astrophysics
Astronomy
Scientific paper
This paper reports a blind search for planetary magnetospheric emissions from planets around nearby stars. Young stars are likely to have much stronger stellar winds than the Sun, and because planetary magnetospheric emissions are powered by stellar winds, stronger stellar winds may enhance the radio luminosity of any orbiting planets. Using various stellar catalogs, we selected nearby stars (< 30 pc) with relatively young age estimates (< 3 Gyr), finding between 100 and several hundred stars. We stacked images from the 74-MHz (4-m wavelength) VLA Low-frequency Sky Survey, obtaining 3\sigma limits on planetary emission of between 10 and 33 mJy. These flux density limits correspond to average planetary luminosities less than 5--10 x 1023erg/s. Using models for the scaling of stellar wind velocity, density, and magnetic field with stellar age, we estimate scaling factors for the strength of stellar winds, relative to the Sun, in our samples. The typical kinetic (magnetic) energy carried by the stellar winds in our samples is 15--50 (5--10) times larger than that of the solar wind. If we assume that every star is orbited by a Jupiter-like planet with a luminosity larger than that of the Jovian decametric radiation by the above factors, our limits on planetary luminosities from the stacking analysis are likely to be a factor of 300 above what would be required to detect the planets in a statistical sense. Similar statistical analyses with observations by future instruments, such as the Low Frequency Array (LOFAR) and the Long Wavelength Array (LWA), offer the promise of improvements by factors of 10--100.
Basic research in radio astronomy at NRL is supported by 6.1 Base funding. The LUNAR consortium, is funded by the NASA Lunar Science Institute (Cooperative Agreement NNA09DB30A) to investigate concepts for astrophysical observatories on the Moon.
Carmichael S.
Clark James
Elkins E.
Gudmundsen P.
Hennig L. A.
No associations
LandOfFree
A Blind Search for Magnetospheric Emissions from Planetary Companions to Nearby Solar-type Stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Blind Search for Magnetospheric Emissions from Planetary Companions to Nearby Solar-type Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Blind Search for Magnetospheric Emissions from Planetary Companions to Nearby Solar-type Stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-967105