Polarization in exoplanetary systems caused by transits, grazing transits, and starspots

Abstract

We present results of numerical simulations of flux and linear polarization variations in transiting exoplanetary systems, caused by the host star disk symmetry breaking. We consider different configurations of planetary transits depending on orbital parameters. Starspot contribution to the polarized signal is also estimated. Applying the method to known systems and simulating observational conditions, a number of targets is selected where transit polarization effects could be detected. We investigate several principal benefits of the transit polarimetry, particularly, for determining orbital spatial orientation and distinguishing between grazing and near-grazing planets. Simulations show that polarization parameters are also sensitive to starspots, and they can be used to determine spot positions and sizes.

39 pages, 10 figures, 1 table, accepted to ApJ

References in corpus (10)

• EXOFAST: A fast exoplanetary fitting suite in IDL
• Stellar activity of planetary host star HD 189733
• The Transit Light Curve Project. V. System Parameters and Stellar Rotation Period of HD 189733
• WASP-80b: a gas giant transiting a cool dwarf
• The Rotation Period of the Planet-Hosting Star HD 189733
• Estimating stellar rotation from starspot detection during planetary transits
• First detection of polarized scattered light from an exoplanetary atmosphere
• Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo
• Toward the Detection of Exoplanet Transits with Polarimetry
• Center-to-limb polarization in continuum spectra of F, G, K stars

Cited by in corpus (4)

• Spatially resolved spectroscopy across stellar surfaces. I. Using exoplanet transits to analyze 3-D stellar atmospheres
• Blue, white, and red ocean planets - Simulations of orbital variations in flux and polarization colors
• Colors of an Earth-like exoplanet -- Temporal flux and polarization signals of the Earth
• Computation of the transmitted and polarized scattered fluxes by the exoplanet HD 189733b in X-rays