Asteroid shapes and thermal properties from combined optical and mid-infrared photometry inversion
Result description
Optical lightcurves can be used for the shape and spin reconstruction of asteroids. Due to unknown albedo, these models are scale-free. When thermal infrared data are available, they can be used for scaling the shape models and for deriving thermophysical properties of the surface by applying a thermophysical model. We introduce a new method of simultaneous inversion of optical and thermal infrared data that allows the size of an asteroid to be derived along with its shape and spin state. The method optimizes all relevant parameters (shape and its size, spin state, light-scattering properties, thermal inertia, surface roughness) by gradient-based optimization. The thermal emission is computed by solving the 1-D heat diffusion equation. Calibrated optical photometry and thermal fluxes at different wavelengths are needed as input data. We demonstrate the reliability and test the accuracy of the method on selected targets with different amount and quality of data. Our results in general agree with those obtained by independent methods. Combining optical and thermal data into one inversion method opens a new possibility for processing photometry from large optical sky surveys with the data from WISE. It also provides more realistic estimates of errors of thermophysical parameters.
Keywords
inversionphotometrymid-infraredopticalcombinedpropertiesthermalshapesAsteroid
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Asteroid shapes and thermal properties from combined optical and mid-infrared photometry inversion
Original language description
Optical lightcurves can be used for the shape and spin reconstruction of asteroids. Due to unknown albedo, these models are scale-free. When thermal infrared data are available, they can be used for scaling the shape models and for deriving thermophysical properties of the surface by applying a thermophysical model. We introduce a new method of simultaneous inversion of optical and thermal infrared data that allows the size of an asteroid to be derived along with its shape and spin state. The method optimizes all relevant parameters (shape and its size, spin state, light-scattering properties, thermal inertia, surface roughness) by gradient-based optimization. The thermal emission is computed by solving the 1-D heat diffusion equation. Calibrated optical photometry and thermal fluxes at different wavelengths are needed as input data. We demonstrate the reliability and test the accuracy of the method on selected targets with different amount and quality of data. Our results in general agree with those obtained by independent methods. Combining optical and thermal data into one inversion method opens a new possibility for processing photometry from large optical sky surveys with the data from WISE. It also provides more realistic estimates of errors of thermophysical parameters.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astronomy & Astrophysics [online]
ISSN
1432-0746
e-ISSN
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Volume of the periodical
604
Issue of the periodical within the volume
07
Country of publishing house
FR - FRANCE
Number of pages
8
Pages from-to
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UT code for WoS article
000408480100117
EID of the result in the Scopus database
2-s2.0-85026524430
Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Astronomy (including astrophysics,space science)
Year of implementation
2017