Combined spin orientation and phase function of asteroids

Abstract

Large surveys provide numerous non-targeted observations of small bodies (SSOs). The upcoming LSST of the Rubin observatory will be the largest source of SSO photometry in the next decade. With non-coordinated epochs of observation, colors, and therefore taxonomy and composition, can only be computed by comparing absolute magnitudes obtained in each filter by solving the phase function (evolution of brightness of the small body against the solar phase angle). Current models in use in the community (HG, HG12* , HG1G2) however fail to reproduce the long-term photometry of many targets due to the change in aspect angle between apparitions. We aim at deriving a generic yet simple phase function model accounting for the variable geometry of the SSOs over multiple apparitions. We propose the sHG1G2 phase function model in which we introduce a term describing the brightness changes due to spin orientation and polar oblateness. We apply this new model to 13,245,908 observations of 122,675 SSOs. These observations were acquired in the g and r filters with the Zwicky Transient Facility. We retrieve them and implement the new sHG1G2 model in Fink, a broker of alerts designed for the LSST. The sHG1G2 model leads to smaller residuals than other phase function models, providing a better description of the photometry of asteroids. We determine the absolute magnitude H and phase function coefficients (G1, G2) in each filter, the spin orientation (RA_0,DEC_0), and the polar-to-equatorial oblateness R for 95,593 Solar System Objects (SSOs), which constitutes about a tenfold increase in the number of characterised objects compared to current census. The application of the sHG1G2 model on ZTF alert data using the FINK broker shows that the model is appropriate to extract physical properties of asteroids from multi-band and sparse photometry, such as the forthcoming LSST survey.

References in corpus (66)

• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• The Zwicky Transient Facility: Science Objectives
• Solar System evolution from compositional mapping of the asteroid belt
• Solar System Objects Observed in the SDSS Commissioning Data
• The taxonomic distribution of asteroids from multi-filter all-sky photometric surveys
• Compositional distributions and evolutionary processes for the near-Earth object population: Results from the MIT-Hawaii Near-Earth Object Spectroscopic Survey (MITHNEOS
• Phase reddening on near-Earth asteroids: Implications for mineralogical analysis, space weathering and taxonomic classification
• The Yarkovsky and YORP Effects
• The Zwicky Transient Facility Alert Distribution System
• Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes
• Hypercalibration: A Pan-STARRS1-based recalibration of the Sloan Digital Sky Survey
• Fink, a new generation of broker for the LSST community
• Asteroid Taxonomy from Cluster Analysis of Spectrometry and Albedo
• Gaia Data Release 2: Observations of solar system objects
• Asteroid lightcurves from the Palomar Transient Factory survey: Rotation periods and phase functions from sparse photometry
• Solar System objects observed with TESS -- First data release: bright main-belt and Trojan asteroids from the Southern Survey
• Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution
• Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry
• Physical Properties of (2) Pallas
• Taxonomic classification of asteroids based on MOVIS near-infrared colors
• ADAM: a general method for using various data types in asteroid reconstruction
• Thermophysical modeling of main-belt asteroids from WISE thermal data
• Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)
• Asteroid phase curves from ATLAS dual-band photometry
• Asteroid models from the Lowell Photometric Database
• A million asteroid observations in the Sloan Digital Sky Survey
• New polarimetric and spectroscopic evidence of anomalous enrichment in spinel-bearing Calcium-Aluminium-rich Inclusions among L-type asteroids
• Unexpected D-type Interlopers in the Inner Main Belt
• Gaia Data Release 3: Reflectance spectra of Solar System small bodies
• An anisotropic distribution of spin vectors in asteroid families
• Asteroid Models from Multiple Data Sources
• Solar System Science with ESA Euclid
• Reconstruction of asteroid spin states from Gaia DR3 photometry
• SsODNet: The Solar system Open Database Network
• Spin states of asteroids in the Eos collisional family
• Adaptive optics and lightcurve data of asteroids: twenty shape models and information content analysis
• Asteroid models reconstructed from the Lowell Photometric Database and WISE data
• Prediction of transits of solar system objects in Kepler/K2 images: An extension of the Virtual Observatory service SkyBoT
• Multi-filter photometry of Solar System Objects from the SkyMapper Southern Survey
• Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids
• Distribution of spin-axes longitudes and shape elongations of main-belt asteroids
• Fink: early supernovae Ia classification using active learning
• Physical, spectral, and dynamical properties of asteroid (107) Camilla and its satellites
• PRIMASS visits Hilda and Cybele groups
• Inversion of asteroid photometry from Gaia DR2 and the Lowell Observatory photometric database
• 101 Trojans: a tale of period bimodality, binaries, and extremely slow rotators from K2 photometry
• Spinning up planetary bodies by pebble accretion
• The determination of asteroid H and G phase function parameters using GAIA DR2
• Precovery of near-Earth asteroids by a citizen-science project of the Spanish Virtual Observatory
• $V$-band photometry of asteroids from ASAS-SN: Finding asteroids with slow spin
• GRANDMA Observations of ZTF/Fink Transients during Summer 2021
• The non-convex shape of (234) Barbara, the first Barbarian
• Reconstruction of asteroid spin states from Gaia DR2 photometry
• Phase integral of asteroids
• Spectral analysis of basaltic asteroids observed by the Gaia space mission
• Gaia search for early-formed andesitic asteroidal crusts
• Properties of slowly rotating asteroids from the Convex Inversion Thermophysical Model
• Absolute colors and phase coefficients of asteroids
• The multi-wavelength phase curves of small bodies: Phase coloring
• Compositional properties of planet-crossing asteroids from astronomical surveys
• Photometry of selected outer main belt asteroids
• Enabling discovery of solar system objects in large alert data streams

Cited by in corpus (7)

• Stellar occultations by Trans-Neptunian Objects
• Transient Classifiers for Fink: Benchmarks for LSST
• Astrometry, orbit determination, and thermal inertia of the Tianwen-2 target asteroid (469219) Kamo`oalewa
• Debiasing astro-Photometric Observations with Corrections Using Statistics (DePhOCUS)
• Characterization of of (98943) 2001 CC${}_{21}$, the target of Hayabusa2$\#$
• Multi-epoch spectro-photometric characterization of the minimoon 2024 PT${}_5$ in the visible and near-infrared
• A catalog of near-IR absolute magnitudes of Solar System small bodies