The modulation of SiO maser polarization by Jovian planets
arXiv:0809.0214 · doi:10.1051/0004-6361/200811537
Abstract
Searching for planets in the atmosphere of AGB stars is difficult, due to confusion with the stellar wind and pulsations. The aim here is to provide a complementary strategy for planet search in such a dense environment. The polarization properties of SiO masers, especially their circular polarization, are, under certain conditions, good tracers for rapid magnetospheric events. A Jovian planet with a magnetosphere whose dipole axis is misaligned with its rotation axis, naturally provides such conditions. Here I present several models showing that the polarization will be periodically modulated. Single-dish monitoring with a sufficiently dense time sampling and a carefully calibrated polarimeter, in combination with VLBI observations, are suited to detect and locate a periodic modulation of the circular maser polarization due to a precessing Jovian magnetosphere. The phenomenon will be rare, because a favourable arrangement of maser and magnetosphere is needed, otherwise the polarization may be below the detection threshold, especially if the maser is unsaturated. Linear polarization, though exhibiting a qualitatively similar modulation, is likely to suffer more from confusion due to beam dilution, even in VLBI observations.
References in corpus (7)
- A Debris Disk Around An Isolated Young Neutron Star
- Can Planets survive Stellar Evolution?
- A Planetary Mass Companion to the K0 Giant HD 17092
- An Improved Model of SiO Maser Emission in Miras
- XPOL - the correlation polarimeter at the IRAM 30m telescope
- Mapping the circumstellar SiO maser emission in R Leo
- Precessing planetary magnetospheres in SiO stars ? First detection of quasi-periodic polarization fluctuations in R Leo and V Cam