Post-Main-Sequence Debris from Rotation-Induced YORP Break-Up of Small Bodies

Total Page:16

File Type:pdf, Size:1020Kb

Post-Main-Sequence Debris from Rotation-Induced YORP Break-Up of Small Bodies MNRAS 445, 2794–2799 (2014) doi:10.1093/mnras/stu1926 Post-main-sequence debris from rotation-induced YORP break-up of small bodies Dimitri Veras,1‹ Seth A. Jacobson2,3 and Boris T. Gansicke¨ 1 1Department of Physics, University of Warwick, Coventry CV4 7AL, UK 2Laboratoire Lagrange, Observatoire de la Coteˆ d’Azur, Boulevard de l’Observatoire, F-06304 Nice Cedex 4, France 3Bayerisches Geoinstitut, Universtat¨ Bayreuth, D-95440 Bayreuth, Germany Accepted 2014 September 14. Received 2014 September 8; in original form 2014 July 24 ABSTRACT Downloaded from Although discs of dust and gas have been observed orbiting white dwarfs, the origin of this circumstellar matter is uncertain. We hypothesize that the in situ break-up of small bodies such as asteroids spun to fission during the giant branch phases of stellar evolution provides an important contribution to this debris. The YORP (Yarkovsky–O’Keefe–Radviesvki–Paddock) effect, which arises from radiation pressure, accelerates the spin rate of asymmetric asteroids, http://mnras.oxfordjournals.org/ which can eventually shear themselves apart. This pressure is maintained and enhanced around dying stars because the outward push of an asteroid due to stellar mass loss is insignificant compared to the resulting stellar luminosity increase. Consequently, giant star radiation will destroy nearly all bodies with radii in the range 100 m–10 km that survive their parent star’s main-sequence lifetime within a distance of about 7 au; smaller bodies are spun apart to their strongest, competent components. This estimate is conservative and would increase for highly asymmetric shapes or incorporation of the inward drag due to giant star stellar wind. The resulting debris field, which could extend to thousands of au, may be perturbed at University of Colorado on October 21, 2014 by remnant planetary systems to reproduce the observed dusty and gaseous discs which accompany polluted white dwarfs. Key words: Kuiper belt: general – minor planets, asteroids: general – planets and satellites: dynamical evolution and stability – stars: AGB and post-AGB – stars: evolution – white dwarfs. by yielding a lower limit of the order of a micron, but no upper 1 INTRODUCTION limit (Reach et al. 2009). Because the discs are extremely com- Observations unambiguously demonstrate that single white dwarfs pact in radial extent (∼1R), planets have difficulty reaching such (WDs) harbour dusty and gaseous circumstellar discs. The mounting close separations. A single planet’s orbit will be pushed outwards discoveries, particularly within the last decade, result in a current by mass-loss during the giant branch phases of stellar evolution, tally of about 30 dusty discs (Zuckerman & Becklin 1987; Becklin and can reverse direction only by giant star/planet tides (Mustill & et al. 2005; Kilic et al. 2005; Reach et al. 2005; Farihi, Jura & Villaver 2012; Adams & Bloch 2013; Nordhaus & Spiegel 2013; Zuckerman 2009) and 7 gaseous discs (Gansicke¨ et al. 2006, 2008; Villaver et al. 2014), severe anisotropy in the mass-loss distribution Gansicke,¨ Marsh & Southworth 2007;Gansicke¨ 2011;Farihietal. (Veras, Hadjidemetriou & Tout 2013b), or through stellar flybys 2012; Melis et al. 2012); some systems include both dusty and (Veras et al. 2014b). All these scenarios are unlikely, as tidal pre- gaseous discs (Brinkworth et al. 2009; Melis et al. 2010; Brinkworth scriptions would have to be finely tuned to prevent engulfment into et al. 2012). Every one of these discs is accompanied by detections the star, mass-loss can be considered isotropic within a few hundred of metals in WD atmospheres, indicating accretion from the disc. au and the probability of a flyby causing a near-collisional orbital Although we know that the disc matter arises from remnant plan- perturbation is too low. etary systems, we do not know from what part of those systems. Systems with multiple planets present different difficulties. Be- Whether the progenitors, which remain undetected, are planets, as- cause mass-loss changes the stability boundary in multiplanet sys- teroids or comets, they are assumed to be tidally or sublimationally tems (Debes & Sigurdsson 2002; Voyatzis et al. 2013), giant branch disrupted into discs (Graham et al. 1990;Jura2003; Bear & Soker evolution can trigger gravitational scattering instabilities amongst 2013; Stone, Metzger & Loeb 2014; Veras et al. 2014a). Dust mod- the planets. Detailed simulations of two-planet (Veras et al. 2013b) elling provides partial constrains on the particle sizes in these discs and three-planet (Mustill, Veras & Villaver 2014) systems across all phases of evolution, including the main-sequence and WD phases, indicate that the frequency of planets scattered to near-collisional E-mail: [email protected] orbits with the WD is too small to explain the observations. C 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society Post-MS rotational fission of asteroids 2795 Smaller bodies transported inwards from an external reservoir 2008; Rossi, Marzari & Scheeres 2009). Acceleration is also re- represent more likely progenitors. Both compositionally and dy- sponsible for driving small bodies to rotational fission – the process namically, comets cannot be the primary precursor of the discs whereby objects with little or no tensile strength can fall apart and (Zuckerman et al. 2007; Veras, Shannon & Gansicke¨ 2014c), al- their elements enter a mutual orbit due to centrifugal accelerations though comets can contribute to some discs, particularly around the matching or exceeding gravitational accelerations (Scheeres 2007b; youngest WDs (Stone et al. 2014). Walsh, Richardson & Michel 2008; Jacobson & Scheeres 2011). Asteroids1 originating from an external belt are the more likely YORP-induced rotational fission leads to the creation of asteroid choice. By interacting with one planet, a fraction of a belt of debris pairs (Walsh et al. 2008;Pravecetal.2010) and binary asteroids can scatter close to or directly into the WD. Bonsor, Mustill & Wyatt (Jacobson & Scheeres 2011) which match the characteristics of (2011) showed how a planet plus a Kuiper belt analogue can scatter those observed in the Solar system. This fission also significantly some of the belt into inner regions of a WD system. Debes, Walsh affects the size–frequency distribution of the asteroids in the main & Stark (2012) demonstrated that a planet can trap exo-asteroid belt belt (Jacobson et al. 2014). members in an interior mean motion resonance before eventually Consider a solid body in orbit around a star. The evolution of the scattering them to the Roche radius of the WD. Frewen & Hansen spin (s) of this object may be expressed as (Scheeres 2007a) (2014) extended these studies and found that when the planet is of ds Y f a lower mass and eccentric, then more asteroids encounter the WD = √ , (1) 2 2 2 dt 2πρR a − e Downloaded from radius. 1 In summary, although explorations of the potential sources of disc where R is the mean radius of the body, ρ is its density, a and e are progenitors in WD systems are at an early stage, asteroids are likely the semimajor axis and eccentricity of its orbit, f is a force and Y to be the dominant source. This paper proposes that many asteroids ∈ [0, 1) is a constant determined by the physical properties of the will not survive the giant branch stages of stellar evolution intact due body. The value of Y may be thought of as the extent of asymmetry = = / to radiation-induced rotational fission. Consequently, the reservoir of the asteroid. For a perfectly symmetric body, Y 0 ds dt, http://mnras.oxfordjournals.org/ of material available to form discs around WDs is composed of which means that the asteroid’s initial spin angular momentum smaller fragments than what was previously assumed. We describe is conserved and the asteroid maintains its original spin. Some this type of disruption in Section 2 and conclude in Section 3. Solar system-based examples include the asteroids 1862 Apollo, with Y = 0.022 (Kaasalainen et al. 2007) and 54509 YORP, with Y = 0.005 (Taylor et al. 2007). Observational limitations currently 2 SPIN EVOLUTION prevent us from measuring Y for small bodies residing outside of the Solar system. In this section, we first describe the primary driver of spin (Sec- The force f is given by equations 23– 26 of Scheeres (2007a), and tion 2.1) and the critical spin at which disruption occurs (Section 2.2) is a function of the incident stellar light pressure, the body’s albedo, before characterizing the spin evolution along the main sequence at University of Colorado on October 21, 2014 the fraction of radiation pressure due to specular reflection and the (Section 2.3), giant branches (Section 2.4) and WD (Section 2.5) Lambertian scattering coefficient. For the Solar system, this force phases of stellar evolution. We conclude with numerical simulations (f = f) is linearly proportional to the Solar radiation constant, and (Section 2.6). is approximately equal to 1017 kg m s−2. Therefore, we assume here for general planetary systems f = kf,wherek = L/L, such that 2.1 The YORP effect L denotes luminosity. The YORP (Yarkovsky–O’Keefe–Radviesvki–Paddock) effect is the rotational acceleration of a body due to the anisotropic absorp- 2.2 The critical disruption spin tion and radiation of light. The effect was first proposed in the Observations of Solar system asteroids exhibit a sharp and unmis- context of absorbing stellar UV and visible light and the emittance takable cutoff on a rotation period/radius diagram (originally fig. 1 of thermal radiation due to the local heating of the body (Rubincam of Harris 1994 and recently fig. 1 of Jacobson et al. 2014), sug- 2000), although the role of conducted heat is now considered as gesting that asteroids with radii greater than about 250 m break up possibly as important (Golubov & Krugly 2012).
Recommended publications
  • Constraints on the Near-Earth Asteroid Obliquity Distribution from The
    Astronomy & Astrophysics manuscript no. main c ESO 2017 September 4, 2017 Constraints on the near-Earth asteroid obliquity distribution from the Yarkovsky effect C. Tardioli1,?, D. Farnocchia2, B. Rozitis3, D. Cotto-Figueroa4, S. R. Chesley2, T. S. Statler5; 6, and M. Vasile1 1 Department of Mechanical & Aerospace Engineering, University of Strathclyde, Glasgow, G1 1XJ, UK 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA 3 School of Physical Sciences, The Open University, Milton Keynes, MK7 6AA, UK 4 Department of Physics and Electronics, University of Puerto Rico at Humacao, Humacao, 00792, Puerto Rico 5 Department of Astronomy, University of Maryland, College Park, MD, 20742, USA 6 Planetary Science Division, Science Mission Directorate, NASA Headquarters, Washington DC, 20546, USA September 4, 2017 ABSTRACT Aims. From lightcurve and radar data we know the spin axis of only 43 near-Earth asteroids. In this paper we attempt to constrain the spin axis obliquity distribution of near-Earth asteroids by leveraging the Yarkovsky effect and its dependence on an asteroid’s obliquity. Methods. By modeling the physical parameters driving the Yarkovsky effect, we solve an inverse problem where we test different simple parametric obliquity distributions. Each distribution re- sults in a predicted Yarkovsky effect distribution that we compare with a χ2 test to a dataset of 125 Yarkovsky estimates. Results. We find different obliquity distributions that are statistically satisfactory. In particular, among the considered models, the best-fit solution is a quadratic function, which only depends on two parameters, favors extreme obliquities, consistent with the expected outcomes from the YORP effect, has a 2:1 ratio between retrograde and direct rotators, which is in agreement with theoretical predictions, and is statistically consistent with the distribution of known spin axes of near-Earth asteroids.
    [Show full text]
  • Asteroid Regolith Weathering: a Large-Scale Observational Investigation
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2019 Asteroid Regolith Weathering: A Large-Scale Observational Investigation Eric Michael MacLennan University of Tennessee, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Recommended Citation MacLennan, Eric Michael, "Asteroid Regolith Weathering: A Large-Scale Observational Investigation. " PhD diss., University of Tennessee, 2019. https://trace.tennessee.edu/utk_graddiss/5467 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Eric Michael MacLennan entitled "Asteroid Regolith Weathering: A Large-Scale Observational Investigation." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Geology. Joshua P. Emery, Major Professor We have read this dissertation and recommend its acceptance: Jeffrey E. Moersch, Harry Y. McSween Jr., Liem T. Tran Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Asteroid Regolith Weathering: A Large-Scale Observational Investigation A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Eric Michael MacLennan May 2019 © by Eric Michael MacLennan, 2019 All Rights Reserved.
    [Show full text]
  • (68346) 2001 KZ66 from Combined Radar and Optical Observations
    MNRAS 000,1–13 (2021) Preprint 1 September 2021 Compiled using MNRAS LATEX style file v3.0 Detection of the YORP Effect on the contact-binary (68346) 2001 KZ66 from combined radar and optical observations Tarik J. Zegmott,1¢ S. C. Lowry,1 A. Rożek,1,2 B. Rozitis,3 M. C. Nolan,4 E. S. Howell,4 S. F. Green,3 C. Snodgrass,2,3 A. Fitzsimmons,5 and P. R. Weissman6 1Centre for Astrophysics and Planetary Science, University of Kent, Canterbury, CT2 7NH, UK 2Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ, UK 3Planetary and Space Sciences, School of Physical Sciences, The Open University, Milton Keynes, MK7 6AA, UK 4Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA 5Astrophysics Research Centre, Queens University Belfast, Belfast, BT7 1NN, UK 6Planetary Sciences Institute, Tucson, AZ 85719, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT The YORP effect is a small thermal-radiation torque experienced by small asteroids, and is considered to be crucial in their physical and dynamical evolution. It is important to understand this effect by providing measurements of YORP for a range of asteroid types to facilitate the development of a theoretical framework. We are conducting a long-term observational study on a selection of near-Earth asteroids to support this. We focus here on (68346) 2001 KZ66, for which we obtained both optical and radar observations spanning a decade. This allowed us to perform a comprehensive analysis of the asteroid’s rotational evolution. Furthermore, radar observations from the Arecibo Observatory enabled us to generate a detailed shape model.
    [Show full text]
  • Annihilation of Relative Equilibria in the Gravitational Field of Irregular
    Planetary and Space Science 161 (2018) 107–136 Contents lists available at ScienceDirect Planetary and Space Science journal homepage: www.elsevier.com/locate/pss Annihilation of relative equilibria in the gravitational field of irregular-shaped minor celestial bodies Yu Jiang a,b,*, Hexi Baoyin b a State Key Laboratory of Astronautic Dynamics, Xi'an Satellite Control Center, Xi'an, 710043, China b School of Aerospace Engineering, Tsinghua University, Beijing, 100084, China ARTICLE INFO ABSTRACT Keywords: The rotational speeds of irregular-shaped minor celestial bodies can be changed by the YORP effect. This variation Minor celestial bodies in speed can make the numbers, positions, stabilities, and topological cases of the minor body's relative equi- Gravitational potential librium points vary. The numbers of relative equilibrium points can be reduced through the collision and anni- Equilibria hilation of relative equilibrium points, or increase through the creation and separation of relative equilibrium Annihilation points. Here we develop a classification system of multiple annihilation behaviors of the equilibrium points for Bifurcations irregular-shaped minor celestial bodies. Most minor bodies have five equilibrium points; there are twice the number of annihilations per equilibrium point when the number of equilibrium points is between one and five. We present the detailed annihilation classifications for equilibria of objects which have five equilibrium points. Additionally, the annihilation classification for the seven equilibria of Kleopatra-shaped
    [Show full text]
  • Radiation Recoil Effects on the Dynamical Evolution of Asteroids A
    Radiation Recoil Effects on the Dynamical Evolution of Asteroids A dissertation presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Desire´e Cotto-Figueroa December 2013 c 2013 Desire´e Cotto-Figueroa. All Rights Reserved. ! 2 This dissertation titled Radiation Recoil Effects on the Dynamical Evolution of Asteroids by DESIREE´ COTTO-FIGUEROA has been approved for the Department of Physics and Astronomy and the College of Arts and Sciences by Thomas S. Statler Professor of Physics and Astronomy Robert Frank Dean, College of Arts and Sciences 3 A COTTO-FIGUEROA, DESIREE,´ Ph.D., December 2013, Physics and Astronomy Radiation Recoil Effects on the Dynamical Evolution of Asteroids (111 pp.) Director of Dissertation: Thomas S. Statler The Yarkovsky effect is a radiation recoil force that results in a semimajor axis drift in the orbit that can cause Main Belt asteroids to be delivered to powerful resonances from which they could be transported to Earth-crossing orbits. This force depends on the spin state of the object, which is modified by the YORP effect, a variation of the Yarkovsky effect that results in a torque that changes the spin rate and the obliquity. Extensive analyses of the basic behavior of the YORP effect have been previously conducted in the context of the classical spin state evolution of rigid bodies (YORP cycle). However, the YORP effect has an extreme sensitivity to the topography of the asteroids and a minor change in the shape of an aggregate asteroid can stochastically change the YORP torques.
    [Show full text]
  • Cuyo from Ground-Based Optical and Thermal-IR Observations?,?? A
    A&A 627, A172 (2019) Astronomy https://doi.org/10.1051/0004-6361/201834162 & © ESO 2019 Astrophysics Physical model of near-Earth asteroid (1917) Cuyo from ground-based optical and thermal-IR observations?,?? A. Ro˙zek1, S. C. Lowry1, B. Rozitis2, S. F. Green2, C. Snodgrass3,2, P. R. Weissman4, A. Fitzsimmons5, M. D. Hicks6, K. J. Lawrence6, S. R. Duddy1, S. D. Wolters2, G. Roberts-Borsani1,7, R. Behrend8, and F. Manzini9 1 Centre for Astrophysics and Planetary Science, University of Kent, Canterbury, UK e-mail: [email protected] 2 Planetary and Space Sciences, School of Physical Sciences, The Open University, Milton Keynes, UK 3 Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK 4 Planetary Sciences Institute, Tucson, AZ, USA 5 Astrophysics Research Centre, Queens University Belfast, Belfast, UK 6 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA 7 Department of Physics and Astronomy, University College London, London, UK 8 Observatoire de Genève, Sauverny, Switzerland 9 Stazione Astronomica di Sozzago, Sozzago, Italy Received 30 August 2018 / Accepted 3 May 2019 ABSTRACT Context. The near-Earth asteroid (1917) Cuyo was subject to radar and light curve observations during a close approach in 1989, and observed up until 2008. It was selected as one of our ESO Large Programme targets, aimed at observational detections of the Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect through long-term light curve monitoring and physical modelling of near- Earth asteroids. Aims. We aim to constrain the physical properties of Cuyo: shape, spin-state, and spectroscopic and thermo-physical properties of the surface.
    [Show full text]
  • Photometric Survey of the Very Small Near-Earth Asteroids with the SALT Telescope II
    A&A 509, A95 (2010) Astronomy DOI: 10.1051/0004-6361/200913153 & c ESO 2010 Astrophysics Photometric survey of the very small near-Earth asteroids with the SALT telescope II. Discussion of YORP T. Kwiatkowski Astronomical Observatory, Adam Mickiewicz University, Słoneczna 36, 60-286 Poznan,´ Poland e-mail: [email protected] Received 20 August 2009 / Accepted 4 November 2009 ABSTRACT Aims. A possibility of detection of the YORP effect in the population of the very small near-Earth asteroids is discussed. It is probable that due to their significant thermal conductivity, those of the objects which are on low inclination orbits experience a continuous spin-up/spin-down without the typical YORP cycles, and their spin axes are moved towards obliquities of 0◦ and 180◦. Methods. For all rapidly rotating near-Earth asteroids observed with SALT, as well as other such objects for which periods are known, future observing possibilities are identified. A statistically derived, approximate relation for the YORP spin-up/spin-down is then utilized to check which of the considered asteroids can be potentially used to detect this effect. Results. It was found that for two asteroids, 2000 HB24 (if successfully recovered in 2014) and 1998 KY26, rotation period changes due to YORP should be detectable in the future. A determination of obliquities of two other objects, 2001 AV43 and 2006 XY should also be possible. For the latter constraints on its pole position are obtained suggesting a prograde rotation and the spin axis obliquity ≤ 50◦. Key words. techniques: photometric – minor planets, asteroids: general 1.
    [Show full text]
  • Asteroid 2017 FZ2 Et Al.: Signs of Recent Mass-Shedding from YORP?
    MNRAS 000, 1–20 (2017) Preprint 28 September 2017 Compiled using MNRAS LATEX style file v3.0 Asteroid 2017 FZ2 et al.: signs of recent mass-shedding from YORP? C. de la Fuente Marcos⋆ and R. de la Fuente Marcos Universidad Complutense de Madrid, Ciudad Universitaria, E-28040 Madrid, Spain Accepted 2017 September 25. Received 2017 September 25; in original form 2017 June 7 ABSTRACT The first direct detection of the asteroidal YORP effect, a phenomenon that changes the spin states of small bodies due to thermal reemission of sunlight from their surfaces, was obtained for (54509) YORP 2000 PH5. Such an alteration can slowly increase the rotation rate of as- teroids, driving them to reach their fission limit and causing their disruption. This process can produce binaries and unbound asteroid pairs. Secondary fission opens the door to the eventual formation of transient but genetically-related groupings. Here, we show that the small near- Earth asteroid (NEA) 2017 FZ2 was a co-orbital of our planet of the quasi-satellite type prior to their close encounter on 2017 March 23. Because of this flyby with the Earth, 2017 FZ2 has become a non-resonant NEA. Our N-body simulations indicate that this object may have experienced quasi-satellite engagements with our planet in the past and it may return as a co-orbital in the future. We identify a number of NEAs that follow similar paths, the largest named being YORP, which is also an Earth’s co-orbital. An apparent excess of NEAs moving in these peculiar orbits is studied within the framework of two orbit population models.
    [Show full text]
  • Direct Estimation of Yarkovsky Accelerations on Near-Earth Asteroids
    Asteroids, Comets, Meteors (2008) 8330.pdf DIRECT ESTIMATION OF YARKOVSKY ACCELERATION ON NEAR-EARTH ASTEROIDS. S. R. Chesley1, D. Vokrouhlický2, S. J. Ostro3, L. A. M. Benner3, J.-L. Margot4, R. L. Matson5, M. C. Nolan6 and M. K. Shepard7. 1JPL/Caltech, M/S 301-150, Pasadena, CA 91109 ([email protected]), 2Charles Univ., Prague, Czech Rep., 3JPL/Caltech, Pasadena, CA, 4Cornell Univ., Ithaca, NY, 5SAIC, Seal Beach, CA, 6Arecibo Obs., Arecibo, PR, 7Bloomsburg Univ., Bloomsburg, PA. Introduction: We report the results of a compre- analyses of astrometric errors and dynamical and hensive search for evidence of the Yarkovsky Effect in thermal models before the estimated drift rate can be the orbital fits of near-Earth asteroids. The Yarkovsky definitively linked to the Yarkovsky Effect. Effect is a weak nongravitational acceleration associ- In several of these cases a spin state and diameter ated with the anisotropic emission of thermal radiation. are known, allowing a bulk density to be derived from Despite its small magnitude, it has important implica- the strength of the Yarkovsky acceleration, given rea- tions for the dynamical evolution of asteroid popula- sonable assumptions for the asteroids thermal proper- tions [1]. It has so far been directly observed affecting ties. In other cases, typically those without planetary the trajectories of only two asteroids, 6489 Golevka radar observations, little is known about the body and [2] and 152563 (1992 BF) [3]. In previous studies the one can only compare the estimated drift rate to an Yarkovsky acceleration was modeled by solving the approximate upper bound. This may afford some con- surface heat diffusion problem on the asteroid’s sur- straints on the obliquity of the asteroid’s spin axis, as face, either through linear or finite element methods.
    [Show full text]
  • 25143 Itokawa: Direct Detection of the Current Decelerating Spin State Due to YORP Effect
    A&A 472, L5–L8 (2007) Astronomy DOI: 10.1051/0004-6361:20078149 & c ESO 2007 Astrophysics Letter to the Editor 25143 Itokawa: direct detection of the current decelerating spin state due to YORP effect K. Kitazato1,2,M.Abe2, M. Ishiguro3,andW.-H.Ip4 1 Department of Earth and Planetary Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan e-mail: [email protected] 2 Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229-8510, Japan 3 School of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea 4 Institute of Space Science, National Central University, 32054 Chung Li, Taiwan Received 25 June 2007 / Accepted 9 July 2007 ABSTRACT Aims. The Hayabusa mission revealed fundamental physical properties of the small near-Earth asteroid 25143 Itokawa, such as shape and mass, during its rendezvous with the asteroid in 2005. Resulting from this, the YORP-induced change in the asteroid’s spin state has been predicted theoretically. The purpose of this study is to investigate the YORP effect for Itokawa directly from an observational perspective. Methods. A long-term campaign of ground-based photometric observations of Itokawa were performed from March 2001 to December 2006. The observed asteroid lightcurves were compared with numerical modeling using the detailed shape model and global surface photometric properties derived from the Hayabusa mission. Results. As a non-linear time evolution of rotational phase lag is shown, we found that Itokawa has been decreasing its spin rate by ω˙ = −1.2(±0.2) × 10−17 rad s−2.
    [Show full text]
  • List of Publications
    Patrick A. Taylor Contact Lunar and Planetary Institute Office: 281-486-2146 Information Universities Space Research Association Mobile: 443-254-7368 3600 Bay Area Blvd. [email protected] Houston, TX 77058 USA www.naic.edu/∼ptaylor ORCID: 0002-2493-943X Refereed Taylor, P.A., E.G. Rivera-Valent´ın,L.A.M. Benner, S.E. Marshall, A.K. Virkki, F.C.F. Publications Venditti, L.F. Zambrano-Marin, S.S. Bhiravarasu, B. Aponte-Hernandez, C. Rodriguez Sanchez-Vahamonde, and J.D. Giorgini, Arecibo Radar Observations of Near-Earth As- teroid (3200) Phaethon During the 2017 Apparition, Planetary and Space Science 167, 1-8, 2019. Taylor, P.A. and J.L. Margot, Tidal End States of Binary Asteroid Systems with a Nonspherical Component, Icarus 229, 418-422, 2014. Taylor, P.A., and J.L. Margot, Binary Asteroid Systems: Tidal End States and Esti- mates of Material Properties, Icarus 212, 661-676, 2011. Taylor, P.A., and J.L. Margot, Tidal Evolution of Close Binary Asteroid Systems, Celestial Mechanics and Dynamical Astronomy 108, 315-338, 2010. Taylor, P.A., J.L. Margot, D. Vokrouhlick´y,D.J. Scheeres, P. Pravec, S.C. Lowry, A. Fitzsimmons, M.C. Nolan, S.J. Ostro, L.A.M. Benner, J.D. Giorgini, and C. Magri, Spin Rate of Asteroid (54509) 2000 PH5 Increasing Due to the YORP Effect, Science 316, 274-277, 2007. Virkki, A.K., S.E. Marshall, F.C.F. Venditti, L.F. Zambrano-Marin, D.C. Hickson, A. McGilvray, P.A. Taylor, and 23 colleagues, Arecibo Planetary Radar Observations of Near-Earth Asteroids: 2017 December - 2019 December, submitted.
    [Show full text]
  • Goldstone Radar Observations of Horseshoe-Orbiting Near-Earth Asteroid 2013 BS45, a Potential Mission Target
    The Astronomical Journal, 157:24 (7pp), 2019 January https://doi.org/10.3847/1538-3881/aaf04f © 2018. The American Astronomical Society. All rights reserved. Goldstone Radar Observations of Horseshoe-orbiting Near-Earth Asteroid 2013 BS45, a Potential Mission Target Marina Brozović1, Lance A. M. Benner1, Jon D. Giorgini1, Shantanu P. Naidu1 , Michael W. Busch2, Kenneth J. Lawrence1, Joseph S. Jao1, Clement G. Lee1, Lawrence G. Snedeker3, Marc A. Silva3, Martin A. Slade1, and Paul W. Chodas1 1 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099, USA; [email protected] 2 SETI Institute, 189 North Bernardo Ave suite 200, Mountain View, CA 94043, USA 3 SAITECH, Goldstone Deep Space Communication Complex, 59 Goldstone Road, Fort Irwin, CA 92310-5097, USA Received 2018 October 12; revised 2018 November 8; accepted 2018 November 9; published 2018 December 27 Abstract We report radar observations of near-Earth asteroid 2013 BS45 obtained during the 2013 apparition. This object is in a resonant, Earth-like orbit, and it is a backup target for NASA’s NEA Scout mission. 2013 BS45 belongs to the Arjuna orbital domain, which currently has ∼20 discovered representatives. These objects tend to be small and difficult to characterize, and 2013 BS45 is only the third Arjuna object observed with radar to date. We observed 2013 BS45 on three days at Goldstone (8560 MHz, 3.5 cm) between 2013 February 10 and 13. The closest approach occurred on February 12 at a distance of 0.0126 au. We obtained relatively weak echo power spectra and ranging data at resolutions up to 0.125 μs (18.75 m px−1).
    [Show full text]