Analysis of the rotation period of asteroids (1865) Cerberus, (2100) Ra-Shalom, and (3103) Eger - search for the YORP effect
Josef Durech
(1)
,
David Vokrouhlicky
(1)
,
Olexander R. Baransky
(2)
,
Slawomir Breiter
(3)
,
Otabek A. Burkhonov
(4)
,
Walt Cooney
(5)
,
Valerie Fuller
(6)
,
Ninel M. Gaftonyuk
(7)
,
John Gross
(5)
,
Raguli Ya. Inasaridze
(8)
,
Mikko Kaasalainen
(9)
,
Yu. N. Krugly
(10)
,
Otar I. Kvaratskhelia
(8)
,
E. A. Litvinenko
(11)
,
Brent Macomber
(12)
,
Franck Marchis
(12, 13)
,
Igor E. Molotov
(14)
,
Julian Oey
(15)
,
David Polishook
(16)
,
Joseph T. Pollock
(6)
,
Petr Pravec
(17)
,
Krisztian Sarneczky
(18)
,
V. G. Shevchenko
(7)
,
Ivan Slyusarev
(7)
,
Robert D. Stephens
(19)
,
Gy. Szabo
(18, 20, 21)
,
Dirk Terrell
(5)
,
Frédéric Vachier
(22)
,
Zach A. Vanderplate
(6)
,
Matti Viikinkoski
(9)
,
Brian D. Warner
(23)
1
Astronomical Institute of Charles University
2 Astronomical Observatory of Kiev
3 Astronomical Observatory [Poznan]
4 Ulugh Beg Astronomical Institute
5 Sonoita Research Observatory
6 Department of Physics and Astronomy [Boone]
7 CrAO - Crimean Astrophysical Observatory
8 Abastumani Astrophysical Observatory
9 Department of Mathematics [Tampere]
10 Institute of Astronomy [Kharkiv]
11 The Central Pulkovo Astronomical Observatory
12 Department of Astronomy [Berkeley]
13 Carl Sagan Center
14 Keldysh Institute of Applied Mathematics
15 Kingsgrove Observatory
16 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
17 Ondřejov Observatory of the Prague Astronomical Institute
18 Konkoly Observatory
19 Goat Mountain Astronomical Research Station
20 Department of Experimental Physics
21 ELTE Gothard Astrophysical Observatory
22 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
23 Palmer Divide Observatory
2 Astronomical Observatory of Kiev
3 Astronomical Observatory [Poznan]
4 Ulugh Beg Astronomical Institute
5 Sonoita Research Observatory
6 Department of Physics and Astronomy [Boone]
7 CrAO - Crimean Astrophysical Observatory
8 Abastumani Astrophysical Observatory
9 Department of Mathematics [Tampere]
10 Institute of Astronomy [Kharkiv]
11 The Central Pulkovo Astronomical Observatory
12 Department of Astronomy [Berkeley]
13 Carl Sagan Center
14 Keldysh Institute of Applied Mathematics
15 Kingsgrove Observatory
16 EAPS - Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge]
17 Ondřejov Observatory of the Prague Astronomical Institute
18 Konkoly Observatory
19 Goat Mountain Astronomical Research Station
20 Department of Experimental Physics
21 ELTE Gothard Astrophysical Observatory
22 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
23 Palmer Divide Observatory
Franck Marchis
- Fonction : Auteur
- PersonId : 755708
- ORCID : 0000-0001-7016-7277
Petr Pravec
- Fonction : Auteur
- PersonId : 764767
- ORCID : 0000-0001-8434-9776
Dirk Terrell
- Fonction : Auteur
- PersonId : 767795
- ORCID : 0000-0001-8406-4172
Matti Viikinkoski
- Fonction : Auteur
- PersonId : 767796
- ORCID : 0000-0001-8601-9164
Résumé
The spin state of small asteroids can change on a long timescale by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, the net torque that arises from anisotropically scattered sunlight and proper thermal radiation from an irregularly-shaped asteroid. The secular change in the rotation period caused by the YORP effect can be detected by analysis of asteroid photometric lightcurves. We analyzed photometric lightcurves of near-Earth asteroids (1865) Cerberus, (2100) Ra-Shalom, and (3103) Eger with the aim to detect possible deviations from the constant rotation caused by the YORP effect. We carried out new photometric observations of the three asteroids, combined the new lightcurves with archived data, and used the lightcurve inversion method to model the asteroid shape, pole direction, and rotation rate. The YORP effect was modeled as a linear change in the rotation rate in time d\omega /dt. Values of d\omega/ dt derived from observations were compared with the values predicted by theory. We derived physical models for all three asteroids. We had to model Eger as a nonconvex body because the convex model failed to fit the lightcurves observed at high phase angles. We probably detected the acceleration of the rotation rate of Eger d\omega / dt = (1.4 +/- 0.6) x 10^{-8} rad/d (3\sigma error), which corresponds to a decrease in the rotation period by 4.2 ms/yr. The photometry of Cerberus and Ra-Shalom was consistent with a constant-period model, and no secular change in the spin rate was detected. We could only constrain maximum values of |d\omega / dt| < 8 x 10^{-9} rad/d for Cerberus, and |d\omega / dt| < 3 x 10^{-8} rad/d for Ra-Shalom.