A general polarimetric model for transiting and non-transiting ringed exoplanets
arXiv:2404.16606 · doi:10.1051/0004-6361/202347194
Abstract
We explore the potential of polarimetry as a tool for detecting and characterizing exorings. For that purpose, we have improved the publicly available photometric code Pryngles by adding the results of radiative transfer calculations that fully include polarization and scattering by irregularly shaped particles. With this improved code, we compute the total and polarized fluxes and the degree of polarization of a ringed gas giant along its orbit. We vary key model parameters such as the orbit inclination, ring size and orientation, particle albedo and optical thickness, and demonstrate the versatility of our code by predicting the total and polarized fluxes of the "puffed-up" planet HIP41378f assuming this planet has an opaque dusty ring. We find that spatially unresolved dusty rings can significantly modify the flux and polarization signals of the light that is reflected. Rings are expected to have a low polarization signal and will generally decrease the degree of polarization as the ring casts a shadow on the planet and/or blocks part of the light the planet reflects. During ring-plane crossings, when the thin ring is illuminated edge-on, a ringed exoplanet's flux and degree of polarization are close to those of a ring-less planet and generally appear as sharp changes in the flux and polarization curves. Ringed planets in edge-on orbits tend to be difficult to distinguish from ring-less planets in reflected flux and degree of polarization. We show that if HIP41378f is surrounded by a ring, its reflected flux (compared to the star) will be of the order of , and the ring would decrease the degree of polarization in a detectable way. The improved version of the photometric code Pryngles that we present here shows that dusty rings may produce distinct polarimetric features in light curves across a wide range of orbital configurations, orientations and ring optical properties.
arXiv comment19 pages, 15 figures
References in corpus (34)
- The K2 Mission: Characterization and Early results
- Images of a fourth planet orbiting HR 8799
- A giant planet imaged in the disk of the young star Beta Pictoris
- A map of the day-night contrast of the extrasolar planet HD 189733b
- The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
- Density of asteroids
- Tracing Magnetic Fields with Aligned Grains
- SPHERE / ZIMPOL high resolution polarimetric imager. I. System overview, PSF parameters, coronagraphy, and polarimetry
- A novel method for identifying exoplanetary rings
- A grid of polarization models for Rayleigh scattering planetary atmospheres
- EXONEST: Bayesian Model Selection Applied to the Detection and Characterization of Exoplanets Via Photometric Variations
- Looking for the rainbow on exoplanets covered by liquid and icy water clouds
- Magnetic shielding of exomoons beyond the circumplanetary habitable edge
- Exploring Whether Super-Puffs Can Be Explained as Ringed Exoplanets
- Phase light curves for extrasolar Jupiters and Saturns
- The detectability of extrasolar planet surroundings - I. Reflected-light photometry of unresolved rings
- Polarized scattered light from self-luminous exoplanets. Three-dimensional scattering radiative transfer with ARTES
- CHEOPS Precision Phase Curve of the Super-Earth 55 Cnc e
- Warm Saturns: On the Nature of Rings around Extrasolar Planets that Reside Inside the Ice Line
- Confirming Variability in the Secondary Eclipse Depth of the Super-Earth 55 Cancri e
- Can planetary rings explain the extremely low density of HIP 41378f?
- The First Near-Infrared Transmission Spectrum of HIP 41378 f, a Low-Mass Temperate Jovian World in a Multi-Planet System
- Circular polarization signals of cloudy (exo)planets
- PyMieDAP: a Python--Fortran tool to compute fluxes and polarization signals of (exo)planets
- Flux and polarization signals of spatially inhomogeneous gaseous exoplanets
- The Origin of Planetary Ring Systems
- 55 Cancri e's occultation captured with CHEOPS
- Weak evidence for variable occultation depth of 55 Cnc e with TESS
- A Framework for Characterizing Transmission Spectra of Exoplanets with Circumplanetary Rings
- Stability and detectability of exomoons orbiting HIP 41378 f, a temperate Jovian planet with an anomalously low apparent density
- Scattered light may reveal the existence of ringed exoplanets
- Traces of exomoons in computed flux and polarization phase curves of starlight reflected by exoplanets
- The bright side of the light curve: a general photometric model of non-transiting exorings
- Scattered polarized radiation of extrasolar circumplanetary rings