J/A+A/682/A29 Detection of the Yarkovsky effect on NEAs (Fenucci+, 2024)
An automated procedure for the detection of the Yarkovsky effect
and results from the ESA NEO Coordination Centre.
Fenucci M., Micheli M., Gianotto F., Faggioli L., Oliviero D., Porru A.,
Rudawska R., Cano J.L., Conversi L., Moissl R.
<Astron. Astrophys. 682, A29 (2024)>
=2024A&A...682A..29F 2024A&A...682A..29F (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets
Keywords: methods: statistical - minor planets, asteroids: general
Abstract:
The measurement of the Yarkovsky effect on near-Earth asteroids (NEAs)
is common practice in orbit determination today, and the number of
detections will increase with the developments of new and more
accurate telescopic surveys. However, the process of finding new
detections and identifying spurious ones is not yet automated, and it
often relies on personal judgment.
We aim to introduce a more automated procedure that can search for NEA
candidates to measure the Yarkovsky effect, and that can identify
spurious detections.
The expected semi-major axis drift on an NEA caused by the Yarkovsky
effect was computed with a Monte Carlo method on a statistical model
of the physical parameters of the asteroid that relies on the most
recent NEA population models and data. The expected drift was used to
select candidates in which the Yarkovsky effect might be detected,
according to the current knowledge of their orbit and the length of
their observational arc. Then, a nongravitational acceleration along
the transverse direction was estimated through orbit determination for
each candidate. If the detected acceleration was statistically
significant, we performed a statistical test to determine whether it
was compatible with the Yarkovsky effect model. Finally, we determined
the dependence on an isolated tracklet.
Among the known NEAs, our procedure automatically found 348 detections
of the Yarkovsky effect that were accepted. The results are overall
compatible with the predicted trend with the the inverse of the
diameter, and the procedure appears to be efficient in identifying and
rejecting spurious detections. This algorithm is now adopted by the
ESA NEO Coordination Centre to periodically update the catalogue of
NEAs with a measurable Yarkovsky effect, and the results are
automatically posted on the web portal.
Description:
The Yarkovsky effect determinations can be used to extrapolate the
ratio of retrograde-to-prograde rotators (R/P), because negative
(positive) semi-major axis drift values are associated with retrograde
(prograde) rotators. To this purpose, we randomly generate 10000
values of A2, for each positive detections. In this process, we
assumed A2 to be a Gaussian random variable, with mean value equal to
the nominal value and standard deviation equal to the 1-σ
uncertainty of the detection.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 185 463 Determinations of A2 with S/N>3
tableb2.dat 119 350 Comparisons with JPL data
tableb3.dat 120 64 Comparisons with JPL data not accepted or
not found by NEOCC
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See also:
B/astorb : Orbits of Minor Planets (Bowell+, 2014-)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Asteroid Name of the asteroid
12- 17 F6.3 mag H Absolute magnitude
19- 26 F8.6 --- RMS RMS of normalized residuals, 7D OD
28- 35 F8.6 --- RMS6D RMS of normalized residuals, 6D OD
37- 48 E12.6 au/d2 A2 Transversal acceleration component
50- 60 E11.6 au/d2 e_A2 Error in A2
62- 73 E12.6 au/Myr da/dt Semi-major axis drift
75- 85 E11.6 au/Myr e_da/dt Error in da/dt
87- 97 E11.9 au/Myr max(da/dt) Maximum da/dt from Monte Carlo model
99-107 F9.5 --- SNR Signal-to-noise of A2 detection
109-112 A4 --- FAccept [1 Rej.] Flag for acceptance of the
detection
114-118 I5 --- NOptObs Number of optical observations
120-121 I2 --- NRejOpt Number of rejected optical observations
in 7D OD
123-124 I2 --- NRej6D Number of rejected optical observations
in 6D OD
126-127 I2 --- NRadObs Number of radar observations
129 I1 --- NRejRad Number of rejected radar obs in 7D OD
131-132 I2 --- NRejRad6D Number of rejected radar obs in 6D OD
134-137 I4 --- NOptOld Number of old observations
139-147 F9.3 m Dlow 15-th percentile of diameter
149-157 F9.3 m Dmed 50-th percentile of diameter
158-166 F9.3 m Dhigh 85-th percentile of diameter
168 I1 --- ModFlag [0/1] Flag for model used in Monte Carlo
170-176 F7.3 h Prot ?=-1 Rotation period of the asteroid
178 A1 --- Tax Taxonomic complex of the asteroid
180-185 F6.3 yr deltat Length of observational arc
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Asteroid Name of the asteroid
12- 23 E12.5 au/d2 A2 Transversal acceleration from NEOCC
25- 35 E11.5 au/d2 e_A2 Error in A2 from NEOCC
37- 45 F9.5 --- SNR Signal-to-noise of A2 from NEOCC
47- 59 E13.5 au/d2 A2j ?=- Transversal acceleration from JPL
61- 69 E9.5 au/d2 e_A2j ?=- Error in A2 from JPL
71- 79 F9.5 --- SNRj ?=- Signal-to-noise of A2 from JPL
81 I1 --- Model [1/3]?=- Dynamical model of JPL
83- 95 F13.10 --- Err1 ?=- Relative error of JPL determination
97-107 F11.9 --- Err2 ?=- Relative error of NEOCC determination
109-119 F11.9 --- chiA2 ?=- Chi value of determination
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Asteroid Name of the asteroid
13- 25 E13.5 au/Myr da/dt(NEOCC) ?=- Semi-major axis drift from NEOCC
28- 46 E19.5 au/Myr e_da/dt(NEOCC) ?=- Error of NEOCC determination
49- 58 F10.7 --- SNR(NEOCC) ?=- Signal-to-noise of NEOCC determination
63- 73 F11.9 --- YM ?=- Maximum da/dt from Monte Carlo model
76- 87 E12.9 au/Myr da/dt(JPL) Semi-major axis drift from JPL
89- 99 E11.5 au/Myr e_da/dt(JPL) Error of JPL determination
103-111 F9.6 --- SNR(JPL) Signal-to-noise of JPL determination
120 I1 --- Model [1/3] Dynamical model used by JPL
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Acknowledgements:
Marco Fenucci, marco.fenucci(at)ext.esa.int
(End) Marco Fenucci [RM, Italy], Patricia Vannier [CDS] 17-Nov-2023