Feasibility of a Search for Planets around Solar-type Stars with a Polarimetric Radial Velocity Meter
Abstract
A method of wavelength calibration is proposed which may enable measuring changes in radial velocity of bright solar-type stars to an accuracy of about 5 meters per second. Such accuracy would be sufficient for detecting Jupiter-like planets around these stars. The stellar spectrum is imaged by a slitless echelle spectrograph onto a 100-channel Digicon image tube. Instrumental profiles of Digicon diodes are narrowed down by a Fabry-Perot etalon, making the profiles less dependent on atmospheric seeing. The spectrograph and the etalon act merely as a series of narrow band filters for the individual diodes; effective wavelengths of these "filters" are monitored by a crystal retarder (phase retardation plate) kept at a constant temperature. For artificially linearly polarized stellar light which passes through this retarder and through a quarter-wave plate, the plane of polarization varies rapidly with wavelength. The precisely measured position angle of polarization provides wavelength calibration for every resolution element in the spectrum.
- Publication:
-
Icarus
- Pub Date:
- January 1976
- DOI:
- 10.1016/0019-1035(76)90181-0
- Bibcode:
- 1976Icar...27...13S
- Keywords:
-
- Extrasolar Planets;
- Polarimetry;
- Radial Velocity;
- Stellar Motions;
- Stellar Spectra;
- Bandpass Filters;
- Calibrating;
- Fabry-Perot Spectrometers;
- Feasibility Analysis;
- Image Tubes;
- Polarized Light;
- Stellar Luminosity