J/A+A/675/A24 Spins of asteroids derived from DR3 photometry (Durech+, 2023)
Reconstruction of asteroid spin states from Gaia DR3 photometry.
Durech J., Hanus J.
<Astron. Astrophys. 675, A24 (2023)>
=2023A&A...675A..24D 2023A&A...675A..24D (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Photometry ; Optical
Keywords: minor planets, asteroids: general - methods: data analysis -
techniques: photometric
Abstract:
Gaia Data Release 3 contains accurate photometric observations of more
than 150000 asteroids covering a time interval of 34 months. With a
total of about 3000000 measurements, a typical number of
observations per asteroid ranges from a few to several tens. We aimed
to reconstruct the spin states and shapes of asteroids from this
dataset. We computed the viewing and illumination geometry for each
individual observation and used the light curve inversion method to
find the best-fit asteroid model, which was parameterized by the
sidereal rotation period, the spin axis direction, and a
low-resolution convex shape. To find the best-fit model, we ran the
inversion for tens of thousands of trial periods on interval 2-10000h,
with tens of initial pole directions. To find the correct rotation
period, we also used a triaxial ellipsoid model for the shape
approximation. In most cases the number of data points was
insufficient to uniquely determine the rotation period. However, for
about 8600 asteroids we were able to determine the spin state uniquely
together with a low-resolution convex shape model. This large sample
of new asteroid models enables us to study the spin distribution in
the asteroid population. The distribution of spins confirms previous
findings that (i) small asteroids have poles clustered toward ecliptic
poles, likely because of the YORP-induced spin evolution, (ii)
asteroid migration due to the Yarkovsky effect depends on the spin
orientation, and (iii) members of asteroid families have the sense of
rotation correlated with their proper semimajor axis: over the age of
the family, orbits of prograde rotators evolved, due to the Yarkovsky
effect, to larger semimajor axes, while those of retrograde rotators
drifted in the opposite direction.
Description:
Table 3: Spins of asteroids derived from DR3 photometry. For each
asteroid we report its spin axis direction in ecliptic latitude
lambda_1 and longitude beta_1 (the second pole solution has ecliptic
coordinates lambda_2 and longitude beta_2, the sidereal rotation
period P, the number N of photometric measurements in DR3, and the
method used for computing periodograms: C - convex shape models,
E - ellipsoids, CE - both methods provided the same period. The
uncertainty of the rotation period P is on the order of the last
decimal place.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 57 8596 Spins of asteroids derived from DR3 photometry
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014)
Byte-by-byte Description of file: table3.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- 27 D3.2 deg lambda1 Ecliptic pole longitude (J2000.0) for model 1
29- 31 D3.2 deg beta1 Ecliptic pole latitude (J2000.0) for model 1
33- 35 D3.2 deg lambda2 ? Ecliptic pole longitude (J2000.0) for model 2
37- 39 D3.2 deg beta2 ? Ecliptic pole latitude (J2000.0) for model 2
41- 51 F11.6 h P Sidereal period of rotation
53- 54 I2 --- N Number of photometric points
56- 57 A2 --- Method Method used for period determination (1)
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Note (1): Method used to derive the unique rotation period as follows:
C = convex inversion
E = ellipsoids
CE = both methods gave the same unique period
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Acknowledgements:
Josef Durech, durech(at)sirrah.troja.mff.cuni.cz
(End) Josef Durech [Charles University], Patricia Vannier [CDS] 09-Jun-2023