J/AJ/161/112 2012 and 2017 light curves of asteroid 2012 TC4 (Lee+, 2021)
Spin change of asteroid 2012 TC4 probably by radiation torques.
Lee H.-J., Durech J., Vokrouhlicky D., Pravec P., Moon H.-K., Ryan W.,
Kim M.-J., Kim C.-H., Choi Y.-J., Bacci P., Pollock J., Apitzsch R.
<Astron. J., 161, 112 (2021)>
=2021AJ....161..112L 2021AJ....161..112L
ADC_Keywords: Minor planets; Solar system; Photometry, infrared; Optical
Keywords: Asteroids ; Close encounters ; Near-Earth objects ; Minor planets ;
Small solar system bodies
Abstract:
Asteroid 2012TC4 is a small (∼10m) near-Earth object that was observed
during its Earth close approaches in 2012 and 2017. Earlier analyses
of light curves revealed its excited rotation state. We collected all
available photometric data from the two apparitions to reconstruct its
rotation state and convex shape model. We show that light curves from
2012 and 2017 cannot be fitted with a single set of model parameters;
the rotation and precession periods are significantly different for
these two data sets, and they must have changed between or during the
two apparitions. Nevertheless, we could fit all light curves with a
dynamically self-consistent model assuming that the spin states of
2012TC4 in 2012 and 2017 were different. To interpret our results, we
developed a numerical model of its spin evolution in which we included
two potentially relevant perturbations: (I) gravitational torque due
to the Sun and Earth and (II) radiation torque, known as the
Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. Despite our model
simplicity, we found that the role of gravitational torques is
negligible. Instead, we argue that the observed change of its spin
state may be plausibly explained as a result of the YORP torque. To
strengthen this interpretation, we verify that (I) the internal energy
dissipation due to material inelasticity and (II) an impact with a
sufficiently large interplanetary particle are both highly unlikely
causes of its observed spin state change. If true, this is the first
case where the YORP effect has been detected for a tumbling body.
Description:
Photometric observations of 2012 TC4 from 2012 and 2017 were made
using a variety of telescopes having apertures between 0.35 and 5m and
equipped with CCD cameras.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figb1.dat 55 1296 Light curve fits for data in 2012
figb2.dat 55 677 Light curve fits for data in 2012
figb3.dat 65 962 Light curve fits for data in 2017
figb4.dat 65 320 Light curve fits for data in 2017
figb5.dat 65 1254 Light curve fits for data in 2017
figb6.dat 65 3123 Light curve fits for data in 2017
figb7.dat 65 2992 Light curve fits for data in 2017
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See also:
I/317 : The PPMXL Catalog (Roeser+ 2010)
J/A+A/529/A107 : Photometry of 4 main belt asteroids (Marciniak+, 2011)
J/A+A/545/A131 : Photometry of 8 main belt asteroids (Marciniak+, 2012)
J/A+A/550/L11 : Lightcurves of Near-Earth Asteroid 162173 (Kim+ 2013)
J/A+A/559/A106 : Time-series photometry of 2012 DA14 (Terai+, 2013)
J/A+A/562/A48 : Light curves of asteroid (25143) Itokawa (Lowry+, 2014)
J/AJ/150/75 : Asteroid light curves from PTF survey (Waszczak+, 2015)
J/A+A/596/A40 : Main-belt asteroids optical light curves (Szabo+, 2016)
J/A+A/598/A63 : 2015 TB145 light curve (Mueller+, 2017)
J/A+A/619/A123 : Lightcurves of Near-Earth Asteroid 3200 Phaethon (Kim+ 2018)
J/ApJS/245/29 : Main-belt asteroid photometry from TESS (McNeill+, 2019)
J/AJ/159/25 : PS1 light curves and Prots of new asteroids (Lo+, 2020)
Byte-by-byte Description of file: figb[12].dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d JD Julian Date of the observation
16- 27 E12.6 --- Flux Normalized flux
29- 37 A9 --- Tel Telescope identifier (1)
39- 50 A12 "Y/M/D" Date Observation date
52- 55 F4.1 deg alpha Solar phase angle
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Note (1): Telescopes as follows:
MRO = The Magdalena Ridge Observatory 2.4m , New Mexico, V-band
OAVdA = The terrace of the Astronomical Observatory of the Autonomous
Region of the Valle d'Aosta 0.81m, Italy, C-band
PDO = The Palmer Divide Observatory 0.35m, Colorado, V-band
Pistoiese = The Pistoia Mountains Astronomical Observatory 0.6m, Italy, R-band
WISE = Wise Observatory 0.72m, Israel, V-band
PROMPT1 = Panchromatic Robotic Optical Monitoring and Polarimetry Telescope
0.41m, Chile
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Byte-by-byte Description of file: figb[3-7].dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d JD Julian Date of the observation
16- 27 E12.6 --- Flux Normalized flux
29- 47 A19 --- Tel Telescope identifier (1)
49- 60 A12 "Y/M/D" Date Observation date
62- 65 F4.1 deg alpha Solar phase angle
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Note (1): Telescopes as follows:
Kiso = 1,05m at Kiso Observatory, Japan, SG-band
LCO-A = Las Cumbres Observatory 1m, Chile, SR-Band
LCO-C SI = Las Cumbres Observatory 1m, Chile, SI-Band
LCO-C SR = Las Cumbres Observatory 1m, Chile, SR-Band
MRO = The Magdalena Ridge Observatory 2.4m , New Mexico, R and V-band
PDO = The Palmer Divide Observatory 0.35m, Colorado, V-band
SOAR = The Southern Astrophysical Research 4.1m, Chile, SR-band
WISE = Wise Observatory 0.72m, Israel, V-band
BSGC SG = The Bisei Spaceguard Center 1m, Japan, SG-Band
BSGC SI = The Bisei Spaceguard Center 1m, Japan, SI-Band
BSGC SR = The Bisei Spaceguard Center 1m, Japan, SR-Band
BSGC SZ = The Bisei Spaceguard Center 1m, Japan, SZ-Band
Lulin = 1m at Lulin Observatory, Taiwan
Nayoro = 0.4m at Nayoro Observatory, Japan, V-band
KMTNet = The Korea Microlensing Telescope Network 1.6m , South Africa, V-band
Pistoiese = The Pistoia Mountains Astronomical Observatory 0.6m, Italy, R-band
USNA = United States Naval Observatory 0.51m, USA, V-band
WISE = Wise Observatory 0.72m, Israel, V-band
Anan Science Center = Anan Science Center, Japan, V-band
AIRA = Astronomical Institute of the Romanian Academy 0.38m, Romania, V-band
Wildberg = Wildberg Observatory 0.35m, Germany
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 19-Apr-2021