VII/288 Asteroid phase curve coefficients from ATLAS observations (Mahlke+ 2020)
Asteroid phase curves from ATLAS dual-band photometry.
Mahlke M., Carry B., Denneau L.
<Icarus, 354, 114094 (2020)>
=2020yCat.7288....0M 2020yCat.7288....0M
ADC_Keywords: Minor planets ; Photometry, CCD
Keywords: asteroids: compositions - asteroid: surfaces - asteroids: photometry
Abstract:
Asteroid phase curves are used to derive fundamental physical
properties through the determination of the absolute magnitude H. The
upcoming visible Legacy Survey of Space and Time (LSST) and
mid-infrared Near-Earth Object Surveillance Mission (NEOSM) surveys
rely on these absolute magnitudes to derive the colours and albedos of
millions of asteroids. Furthermore, the shape of the phase curves
reflects their surface compositions, allowing for conclusions on their
taxonomy. We derive asteroid phase curves from dual-band photometry
acquired by the Asteroid Terrestrial-impact Last Alert System
telescopes. Using Bayesian parameter inference, we retrieve the
absolute magnitudes and slope parameters of 127012 phase curves of
94777 asteroids in the photometric H, G1, G2- and H, G12*-systems.
The taxonomic complexes of asteroids separate in the observed G1,
G2-distributions, correlating with their mean visual albedo. This
allows for differentiating the X-complex into the P-, M-, and
E-complexes using the slope parameters as alternative to albedo
measurements. Further, taxonomic misclassifications from
spectrophotometric datasets as well as interlopers in dynamical
families of asteroids reveal themselves in G1, G2-space. The H,
G12*-model applied to the serendipitous observations is unable to
resolve target taxonomy. The G1, G2 phase coefficients show
wavelength-dependency for the majority of taxonomic complexes. Their
values allow for estimating the degree of phase reddening of the
spectral slope. The uncertainty of the phase coefficients and the
derived absolute magnitude is dominated by the observational coverage
of the opposition effect rather than the magnitude dispersion induced
by the asteroids' irregular shapes and orientations. Serendipitous
asteroid observations allow for reliable phase curve determination for
a large number of asteroids. To ensure that the acquired absolute
magnitudes are suited for colour computations, it is imperative that
future surveys densely cover the opposition effects of the phase
curves, minimizing the uncertainty on H. The phase curve slope
parameters offer an accessible dimension for taxonomic classification,
correlating with the albedo and complimentary to the spectral
dimension.
Description:
Phase curve coefficients for 127,012 non-targeted phase curves
observed by the Asteroid Terrestrial-impact Last Alert System (ATLAS)
observatory in cyan and orange. The phase curves were fit with the H,
G1, G2- and H, G12* - models (Muinonen et al., 2010Icar..209..542M 2010Icar..209..542M ,
Pentilla et al., 2016). Provided are the best fit parameters for each
model, as well as the 95% highest density interval borders, reference
taxonomic classification and albedo values if available, and proper
orbital elements and family membership status from the Asteroids
Dynamic Site (AstDyS).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
phase.dat 846 127012 Phase curve coefficients of asteroids
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014-)
https://newton.spacedys.com/astdys : AstDyS-2 Home Page
Byte-by-byte Description of file: phase.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Number ? Asteroid number
8- 23 A16 --- Name Asteroid name or designation
25 A1 --- Band [co] Observation band: (c)yan or (o)range)
27- 30 A4 --- Class Taxonomic class from reference
32- 40 A9 --- Scheme Taxonomic scheme from reference
42- 60 A19 --- r_Class Bibcode of taxonomy reference
62- 79 F18.16 AU ap ? Proper semi-major axis
81-101 F21.19 --- ep ? Proper eccentricity
103-122 F20.17 --- ip ? Proper inclination
124-126 I3 --- N Number of ATLAS observations
128-147 F20.18 deg phmin Minimum observed phase angle
149-167 F19.15 deg phmax Maximum observed phase angle
169-187 F19.16 mag H ? H from H,G1,G2-model fit
189-209 F21.19 --- G1 ? G1 from H,G1,G2-model fit
211-232 F22.20 --- G2 ? G2 from H,G1,G2-model fit
234-252 F19.17 mag rms Root-mean-square error of H,G1,G2-model fit
254-272 F19.16 mag H12 H12 from H,G12*-model fit
274-294 F21.19 --- G12 H12 from H,G12*-model fit
296-315 F20.18 mag rms12 Root-mean-square error of H,G12*-model fit
317-335 F19.16 mag B_H ? Upper HDI of H from H,G1,G2-model fit
337-355 F19.16 mag b_H ? Lower HDI of H from H,G1,G2-model fit
357-377 F21.19 --- B_G1 ? Upper HDI of G1 from H,G1,G2-model fit
379-400 E22.18 --- b_G1 ? Lower HDI of G1 from H,G1,G2-model fit
402-422 F21.19 --- B_G2 ? Upper HDI of G2 from H,G1,G2-model fit
424-445 E22.18 --- b_G2 ? Lower HDI of G2 from H,G1,G2-model fit
447-465 F19.16 mag B_H12 Upper HDI of H from H,G12*-model fit
467-485 F19.16 mag b_H12 Lower HDI of H from H,G12*-model fit
487-507 F21.19 --- B_G12 Upper HDI of G12 from H,G12*-model fit
509-530 E22.18 --- b_G12 Lower HDI of G12 from H,G12*-model fit
532-551 F20.18 --- albedo ? Weighted mean of reference albedo values
553-573 F21.19 --- e_albedo ? Error of weighted mean of albedo
575-813 A239 --- r_albedo Bibcodes of albedo reference values
815-820 I6 --- FamilyNumber ? Family number of asteroid from AstDyS
822-834 A13 --- FamilyName Family name of asteroid from AstDyS
836-846 A11 --- FamilyStatus Family status of asteroid from AstDyS
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Acknowledgements:
Max Mahlke, max.mahlke(at)oca.eu
(End) Max Mahlke [OCA, France], Patricia Vannier [CDS] 04-Sep-2020