Morphological Properties Determination of Main Belt Asteroids

Total Page:16

File Type:pdf, Size:1020Kb

Morphological Properties Determination of Main Belt Asteroids MORPHOLOGICAL PROPERTIES DETERMINATION OF MAIN BELT ASTEROIDS by Guillermo Cerdán Hernandez Thesis submitted as a partial requirement to obtain the degree of MASTER OF SCIENCE IN SPACE SCIENCE AND TECHNOLOGY at Instituto Nacional de Astrofísica, Óptica y Electrónica April 2019 Tonantzintla, Puebla Supervised by: Dr. José Ramón Valdés Parra Dr. José Silviano Guichard Romero c INAOE 2019 The author hereby grants to INAOE permission to reproduce and distribute copies of this thesis document in whole or in part. Abstract We used lightcurves from the Asteroid Lightcurve Photometry Database (ALCDEF), observations made at Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE, México) Schmidt telescope, and Minor Planet Observer Lightcurve Inversion software (MPO LC Invert) to make the lightcurve inversion process, deriving shape, and pole orientation for the asteroids: (22) Kallipe, (287) Nepthys, (711) Marmulla, (1117) Reginita, (1318) Nerina, (1346) Gotha, (1492) Oppozler, (3028) Zhangguoxi, (3800) Karayusuf, (4713) Steel, and (5692) Shirao. Fueron usadas curvas de luz de la base de datos de la Asteroid Photometry Database (ALCDEF), observaciones hechas en el telescopio Schmidt del Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE, México) y el software del Minor Planet Observer Lightcurve Inversion (MPO LC Invert, para aplicar el proceso de inversión de cruvas de luz, obteniendo la forma y la orientación del polo para los asteroides: (22) Kallipe, (287) Nepthys, (711) Marmulla, (1117) Reginita, (1318) Nerina, (1346) Gotha, (1492) Oppozler, (3028) Zhangguoxi, (3800) Karayusuf, (4713) Steel y (5692) Shirao. Acknowledgments I thank CONACYT for granting the financial, intellectual capital, and infrastructure support to carry out this thesis work. Likewise, I thank all the people who have contributed in my life and who have allowed me to live this experience, people like: Dolores Hernandez Gonzalez, Juan Carlos Herrera Tavera, Jose Ramón Valdes Parra, Karem Contreras Aguilera, trench companions, and the teachers with vocations who have instructed me. Also, I want to thank the people who have hindered my life, without them I could not have reached this moment, people like my fifth grade teacher Cristino, Francisco Narro, Dulce Cruz, the Refrescos King administrators, and many others, without the rocks that they threw at me I could not have built my temple to virtue and science. V Contents Contents VII 1. INTRODUCTION AND BACKGROUND 1 1.1. INTRODUCTION ............................ 1 1.2. SPACE ENVIRONMENT DELIMITATION AND DEFINITION . 3 1.3. ASTEROIDS MORPHOLOGY AND DEFINITION .......... 3 1.3.1. DEFINITION ........................... 3 1.3.2. RUBBLE PILE OR MONOLITHS ............... 5 1.3.3. BINARIES OR MICRO-SYSTEM ASTEROIDS . 5 1.3.4. SPECTRA ............................ 6 1.3.5. ASTEROIDS NOMENCLATURE ................ 6 1.3.6. CURRENT PROVISIONAL DESIGNATION FOR ASTEROIDS 7 1.3.7. ORBITAL ELEMENTS ..................... 9 1.3.8. ORBIT PERTURBATIONS ................... 9 1.4. MAIN BELT ASTEROIDS ........................ 13 1.4.1. MAIN BELT FORMATION AND DISTRIBUTION OF ASTEROIDS ........................... 14 1.5. OTHER MORPHOLOGY PARAMETERS AND CHARACTERISTICS 17 1.5.1. (H) ASTEROID ABSOLUTE MAGNITUDE . 17 1.5.2. SLOPE PARAMETER (G) .................... 18 1.5.3. H-G ................................ 18 1.5.4. ASTROMETRY AND PHOTOMETRY . 19 1.5.5. H-G PARAMETER AND H-G1G2 . 21 1.6. DETERMINATION OF ASTEROID CHARACTERISTICS FROM LIGHTCURVES ............................. 23 2. Problem Statement 25 2.1. BRIEF IMPLICIT PHILOSOPHICAL JUSTIFICATION . 25 2.2. WHY DETERMIN ASTEROIDS PROPERTIES? . 26 2.3. DISCOVERIES MADE BY STATISTICAL ANALYSIS . 27 2.3.1. RUBBLE PILE SPIN BARRIER . 27 2.4. EARTH DEFENCE ............................ 28 2.5. ASTEROID MINING ........................... 29 VII 2.5.1. GROUND-BASED VISUAL OBSERVATIONS AND ANALYSIS ............................ 30 2.6. FUTURE SPACIAL PROBES TO ASTEROIDS . 30 3. METHODOLOGY 33 3.1. FINDING MORPHOLOGICAL PARAMETERS . 33 3.2. TONANTZINTLA SCHMIDT TELESCOPE . 34 3.3. ELECTRONIC DETECTOR ....................... 38 3.4. SCHMIDT TELESCOPE AND CCD CHARACTERISTICS . 39 3.5. ASTRONOMICAL OBSERVATIONS . 41 3.5.1. PLANING AND SELECTING OBJECTS . 41 3.5.2. CCD SETTINGS ......................... 43 3.5.3. IMAGE REDUCTION BY IRAF . 44 3.6. MPO CANOPUS ............................. 46 3.6.1. CONFIGURATION SETTINGS . 46 3.6.2. APERTURES ........................... 46 3.6.3. ASTROMETRY ......................... 46 3.6.4. MPO CANOPUS PHOTOMETRY SESSION . 46 3.6.5. VERIFYING COMPARISON STARS . 50 3.6.6. MERGE SESSIONS ....................... 50 3.6.7. PERIOD SPECTRUM ANALYZIS . 51 3.6.8. CSmin/CSmax .......................... 54 3.7. LIGHTCURVE INVERSION ....................... 54 3.7.1. MINKOWSKI REDUCTION . 61 3.8. LIGHT CURVE INVERSION WITH LC INVERT . 61 3.8.1. DATA SELECTION ....................... 62 3.8.2. IMPORTING LIGHTCURVE FORMATS . 62 3.8.3. SYNODIC PERIOD FINDING . 63 3.8.4. SEARCHING POLE ORIENTATION . 64 3.8.5. MINKOWSKI MODELING ................... 65 4. OBSERVATIONS 67 4.1. LIGHTCURVES REPORT ........................ 67 4.2. OBSERVATIONS REPORT ....................... 67 4.2.1. DATABASES REPORT ..................... 71 4.3. OBSERVATIONS AND DATABASE GRAPHIC REPORTS . 75 4.3.1. SCHMIDT TELESCOPE OBSERVATIONS LIGHTCURVES . 75 5. RESULTS 95 5.1. (22) KALLIOPE ............................. 98 5.1.1. DAMIT LIGHTCURVES OF (22) KALLIOPE . 98 5.1.2. PERIODS REPORTED FOR (22) KALLIOPE . 100 VIII 5.1.3. DAMIT SHAPE RECREATION FOR (22)KALLIOPE USING DAMIT PARAMETERS . 100 5.1.4. DAMIT SHAPE RECREATION FOR (22) KALLIOPE FOLLOWING THE PROCESS OF SEARCH PERIOD AND POLES WITH LC INVERT . 101 5.1.5. LIGHT CURVE INVERSION FOR (22)KALLIOPE USING ALCDEF AND INAOE OBSERVATIONS . 105 5.2. (287) NEPTHYS .............................112 5.2.1. DAMIT LIGHTCURVES OF (287) NEPTHYS . 112 5.2.2. PERIODS REPORTED FOR (287) NEPTHYS . 114 5.2.3. DAMIT SHAPE RECREATION FOR (287) NEPHTYS USING DAMIT PARAMETERS . 114 5.2.4. SHAPE FOR (287) NEPHTYS USING DAMIT AND INAOE LIGHTCURVES . 116 5.3. (711) MARMULLA . 122 5.3.1. LIGHTCURVES OF (711) MARMULLA . 122 5.3.2. PERIOD SEARCH INTERVAL . 122 5.3.3. SEARCHING PERIOD FOR (711) MARMULLA USING ALCDEF AND INAOE LIGHTCURVES. 122 5.3.4. SEARCH POLES AND MODEL FOR (711) MARMULLA . 124 5.3.5. GENERATING 3D SHAPE FOR (711) MARMULLA . 126 5.4. (1117) REGINITA ............................127 5.4.1. LIGHTCURVES OF (1117) REGINITA . 127 5.4.2. PERIOD SEARCH INTERVAL . 127 5.4.3. SEARCHING PERIOD FOR (1117) REGINITA USING ALCDEF AND INAOE LIGHTCURVES. 127 5.4.4. SEARCH POLES AND MODEL FOR (1117) REGINITA . 129 5.4.5. GENERATING 3D SHAPE FOR (1117) REGINITA . 131 5.5. (1318) NERINA ..............................132 5.5.1. LIGHTCURVES OF (1318) NERINA . 132 5.5.2. PERIOD SEARCH INTERVAL . 132 5.5.3. SEARCHING PERIOD FOR (1318) NERINA USING ALCDEF AND INAOE LIGHTCURVES. 132 5.5.4. SEARCH POLES AND MODEL FOR (1318) NERINA . 134 5.5.5. GENERATING 3D SHAPE FOR (1318) NERINA . 136 5.6. (1346) GOTHA ..............................137 5.6.1. LIGHTCURVES OF (1346) GOTHA . 137 5.6.2. PERIOD SEARCH INTERVAL . 137 5.6.3. SEARCHING PERIOD FOR (1346) GOTHA USING ALCDEF AND INAOE LIGHTCURVES. 137 5.6.4. SEARCH POLES AND MODEL FOR (1346) GOTHA . 139 5.6.5. GENERATING 3D SHAPE FOR (1346) GOTHA . 141 5.7. (1492) OPPOLZER ............................142 IX 5.7.1. LIGHTCURVES OF (1492) OPPOLZER . 142 5.7.2. PERIOD SEARCH INTERVAL . 142 5.7.3. SEARCHING PERIOD FOR (1492) OPPOLZER USING ALCDEF AND INAOE LIGHTCURVES. 142 5.7.4. SEARCH POLES AND MODEL FOR (1492) OPPOLZER . 144 5.7.5. GENERATING 3D SHAPE FOR (1492) OPPOLZER . 146 5.8. (3028) ZHANGGUOXI . 147 5.8.1. LIGHTCURVES OF (3028) ZHANGGUOXI . 147 5.8.2. PERIOD SEARCH INTERVAL . 147 5.8.3. SEARCHING PERIOD FOR (3028) ZHANGGUOXI USING ALCDEF AND INAOE LIGHTCURVES. 147 5.8.4. SEARCH POLES AND MODEL FOR (3028) ZHANGGUOXI 149 5.8.5. GENERATING 3D SHAPE FOR (3028) ZHANGGUOXI . 151 5.9. (3800) KARAYUSUF . 152 5.9.1. LIGHTCURVES OF (3800) KARAYUSUF . 152 5.9.2. PERIOD SEARCH INTERVAL . 152 5.9.3. SEARCHING PERIOD FOR (3800) KARAYUSUF USING ALCDEF AND INAOE LIGHTCURVES. 152 5.9.4. SEARCH POLES AND MODEL FOR (3800) KARAYUSUF . 154 5.9.5. GENERATING 3D SHAPE FOR (3800) KARAYUSUF . 156 5.10. (4713) Steel ................................157 5.10.1. LIGHTCURVES OF (4713) STEEL . 157 5.10.2. PERIOD SEARCH INTERVAL . 157 5.10.3. SEARCHING PERIOD FOR (4713) STEEL USING ALCDEF AND INAOE LIGHTCURVES. 157 5.10.4. SEARCH POLES AND MODEL FOR (4713) STEEL . 159 5.10.5. GENERATING 3D SHAPE FOR (4713) STEEL . 161 5.11. (5692) SHIRAO ..............................162 5.11.1. LIGHTCURVES OF (5692) SHIRAO . 162 5.11.2. PERIOD SEARCH INTERVAL . 162 5.11.3. SEARCHING PERIOD FOR (5692) SHIRAO USING ALCDEF AND INAOE LIGHTCURVES. 162 5.11.4. SEARCH POLES AND MODEL FOR (5692) SHIRAO . 164 5.11.5. GENERATING 3D SHAPE FOR (5692) SHIRAO . 166 6. CONCLUSIONS AND FUTURE WORK. 167 6.1. GENERAL CONCLUSIONS . 167 6.2. RESULTS CONCLUSIONS . 167 6.2.1. ASTEROIDS WITH PARAMETERS DETERMINED BY DAMIT DATABASE. 168 6.3. ASTEROIDS WITH OUT ENTRIES IN DAMIT. 171 6.4. ASTEROIDS WITH NOT ENOUGH COVERAGE OF α or PABL . 171 6.5. FUTURE WORK .............................172 X 6.5.1. RECOMMENDATIONS TO MAKE THE FUTURE OBSERVATIONS . 172 List of Figures 173 List of Tables 181 XI Chapter 1 INTRODUCTION AND BACKGROUND Measure what is measurable, and make measurable what is not so. Galileo Galilei 1.1. INTRODUCTION Scientists and philosophers have been trying to measure, sort out classes, establish ratios and to find reasons why the objects in the physical world are the way they are. To achieve this it is necessary to use instruments but even more, mathematical models that are more sensitive and precise. In 1609, Galileo constructed and pointed skyward his telescope with a power to magnify 20 times. Since that day, the humankind was able to make out mountains and craters on the moon, rings around Saturn, sunspots and moons of Jupiter. The history of the study of asteroids (or minor planets) began with the discovery of Ceres. Located in the main belt, it was observed for the first time in January 1st, 1801 by Guisseppe Piazzi.
Recommended publications
  • Asteroid Shape and Spin Statistics from Convex Models J
    Asteroid shape and spin statistics from convex models J. Torppa, V.-P. Hentunen, P. Pääkkönen, P. Kehusmaa, K. Muinonen To cite this version: J. Torppa, V.-P. Hentunen, P. Pääkkönen, P. Kehusmaa, K. Muinonen. Asteroid shape and spin statistics from convex models. Icarus, Elsevier, 2008, 198 (1), pp.91. 10.1016/j.icarus.2008.07.014. hal-00499092 HAL Id: hal-00499092 https://hal.archives-ouvertes.fr/hal-00499092 Submitted on 9 Jul 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Accepted Manuscript Asteroid shape and spin statistics from convex models J. Torppa, V.-P. Hentunen, P. Pääkkönen, P. Kehusmaa, K. Muinonen PII: S0019-1035(08)00283-2 DOI: 10.1016/j.icarus.2008.07.014 Reference: YICAR 8734 To appear in: Icarus Received date: 18 September 2007 Revised date: 3 July 2008 Accepted date: 7 July 2008 Please cite this article as: J. Torppa, V.-P. Hentunen, P. Pääkkönen, P. Kehusmaa, K. Muinonen, Asteroid shape and spin statistics from convex models, Icarus (2008), doi: 10.1016/j.icarus.2008.07.014 This is a PDF file of an unedited manuscript that has been accepted for publication.
    [Show full text]
  • The Minor Planet Bulletin
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 36, NUMBER 3, A.D. 2009 JULY-SEPTEMBER 77. PHOTOMETRIC MEASUREMENTS OF 343 OSTARA Our data can be obtained from http://www.uwec.edu/physics/ AND OTHER ASTEROIDS AT HOBBS OBSERVATORY asteroid/. Lyle Ford, George Stecher, Kayla Lorenzen, and Cole Cook Acknowledgements Department of Physics and Astronomy University of Wisconsin-Eau Claire We thank the Theodore Dunham Fund for Astrophysics, the Eau Claire, WI 54702-4004 National Science Foundation (award number 0519006), the [email protected] University of Wisconsin-Eau Claire Office of Research and Sponsored Programs, and the University of Wisconsin-Eau Claire (Received: 2009 Feb 11) Blugold Fellow and McNair programs for financial support. References We observed 343 Ostara on 2008 October 4 and obtained R and V standard magnitudes. The period was Binzel, R.P. (1987). “A Photoelectric Survey of 130 Asteroids”, found to be significantly greater than the previously Icarus 72, 135-208. reported value of 6.42 hours. Measurements of 2660 Wasserman and (17010) 1999 CQ72 made on 2008 Stecher, G.J., Ford, L.A., and Elbert, J.D. (1999). “Equipping a March 25 are also reported. 0.6 Meter Alt-Azimuth Telescope for Photometry”, IAPPP Comm, 76, 68-74. We made R band and V band photometric measurements of 343 Warner, B.D. (2006). A Practical Guide to Lightcurve Photometry Ostara on 2008 October 4 using the 0.6 m “Air Force” Telescope and Analysis. Springer, New York, NY. located at Hobbs Observatory (MPC code 750) near Fall Creek, Wisconsin.
    [Show full text]
  • Occultation Newsletter Volume 8, Number 4
    Volume 12, Number 1 January 2005 $5.00 North Am./$6.25 Other International Occultation Timing Association, Inc. (IOTA) In this Issue Article Page The Largest Members Of Our Solar System – 2005 . 4 Resources Page What to Send to Whom . 3 Membership and Subscription Information . 3 IOTA Publications. 3 The Offices and Officers of IOTA . .11 IOTA European Section (IOTA/ES) . .11 IOTA on the World Wide Web. Back Cover ON THE COVER: Steve Preston posted a prediction for the occultation of a 10.8-magnitude star in Orion, about 3° from Betelgeuse, by the asteroid (238) Hypatia, which had an expected diameter of 148 km. The predicted path passed over the San Francisco Bay area, and that turned out to be quite accurate, with only a small shift towards the north, enough to leave Richard Nolthenius, observing visually from the coast northwest of Santa Cruz, to have a miss. But farther north, three other observers video recorded the occultation from their homes, and they were fortuitously located to define three well- spaced chords across the asteroid to accurately measure its shape and location relative to the star, as shown in the figure. The dashed lines show the axes of the fitted ellipse, produced by Dave Herald’s WinOccult program. This demonstrates the good results that can be obtained by a few dedicated observers with a relatively faint star; a bright star and/or many observers are not always necessary to obtain solid useful observations. – David Dunham Publication Date for this issue: July 2005 Please note: The date shown on the cover is for subscription purposes only and does not reflect the actual publication date.
    [Show full text]
  • SMALL BODIES: SHAPES of THINGS to COME 8:30 A.M
    40th Lunar and Planetary Science Conference (2009) sess404.pdf Wednesday, March 25, 2009 SMALL BODIES: SHAPES OF THINGS TO COME 8:30 a.m. Waterway Ballroom 6 Chairs: Al Conrad Debra Buczkowski 8:30 a.m. Conrad A. R. * Merline W. J. Drummond J. D. Carry B. Dumas C. Campbell R. D. Goodrich R. W. Chapman C. R. Tamblyn P. M. Recent Results from Imaging Asteroids with Adaptive Optics [#2414] We report results from recent high-angular-resolution observations of asteroids using adaptive optics (AO) on large telescopes. 8:45 a.m. Marchis F. * Descamps P. Durech J. Emery J. P. Harris A. W. Kaasalainen M. Berthier J. The Cybele Binary Asteroid 121 Hermione Revisited [#1336] The combination of adaptive optics, photometric and Spitzer mid-IR observations of the 121 Hermione binary asteroid system allowed us to confirm the bilobated nature of the primary derived a bulk density of 1.4 g/cc implying a rubble-pile interior. 9:00 a.m. Schmidt B. E. * Thomas P. C. Bauer J. M. Li J. -Y. Radcliffe S. C. McFadden L. A. Mutchler M. J. Parker J. Wm. Rivkin A. S. Russell C. T. Stern S. A. The 3D Figure and Surface of Pallas from HST [#2421] We present Pallas in three dimensions and surface maps. 9:15 a.m. Besse S. * Groussin O. Jorda L. Lamy P. Kaasalainen M. Gesquiere G. Remy E. OSIRIS Team 3-Dimensional Reconstruction of Asteroid 2867 Steins [#1545] The OSIRIS imaging experiment has imaged asteroid Steins. We have combined three methods to retrieve the shape: limbs, Point of Interest and light curves.
    [Show full text]
  • Observations from Orbiting Platforms 219
    Dotto et al.: Observations from Orbiting Platforms 219 Observations from Orbiting Platforms E. Dotto Istituto Nazionale di Astrofisica Osservatorio Astronomico di Torino M. A. Barucci Observatoire de Paris T. G. Müller Max-Planck-Institut für Extraterrestrische Physik and ISO Data Centre A. D. Storrs Towson University P. Tanga Istituto Nazionale di Astrofisica Osservatorio Astronomico di Torino and Observatoire de Nice Orbiting platforms provide the opportunity to observe asteroids without limitation by Earth’s atmosphere. Several Earth-orbiting observatories have been successfully operated in the last decade, obtaining unique results on asteroid physical properties. These include the high-resolu- tion mapping of the surface of 4 Vesta and the first spectra of asteroids in the far-infrared wave- length range. In the near future other space platforms and orbiting observatories are planned. Some of them are particularly promising for asteroid science and should considerably improve our knowledge of the dynamical and physical properties of asteroids. 1. INTRODUCTION 1800 asteroids. The results have been widely presented and discussed in the IRAS Minor Planet Survey (Tedesco et al., In the last few decades the use of space platforms has 1992) and the Supplemental IRAS Minor Planet Survey opened up new frontiers in the study of physical properties (Tedesco et al., 2002). This survey has been very important of asteroids by overcoming the limits imposed by Earth’s in the new assessment of the asteroid population: The aster- atmosphere and taking advantage of the use of new tech- oid taxonomy by Barucci et al. (1987), its recent extension nologies. (Fulchignoni et al., 2000), and an extended study of the size Earth-orbiting satellites have the advantage of observing distribution of main-belt asteroids (Cellino et al., 1991) are out of the terrestrial atmosphere; this allows them to be in just a few examples of the impact factor of this survey.
    [Show full text]
  • Orbital Stability Assessments of Satellites Orbiting Small Solar System Bodies a Case Study of Eros
    Delft University of Technology, Faculty of Aerospace Engineering Thesis report Orbital stability assessments of satellites orbiting Small Solar System Bodies A case study of Eros Author: Supervisor: Sjoerd Ruevekamp Jeroen Melman, MSc 1012150 August 17, 2009 Preface i Contents 1 Introduction 2 2 Small Solar System Bodies 4 2.1 Asteroids . .5 2.1.1 The Tholen classification . .5 2.1.2 Asteroid families and belts . .7 2.2 Comets . 11 3 Celestial Mechanics 12 3.1 Principles of astrodynamics . 12 3.2 Many-body problem . 13 3.3 Three-body problem . 13 3.3.1 Circular restricted three-body problem . 14 3.3.2 The equations of Hill . 16 3.4 Two-body problem . 17 3.4.1 Conic sections . 18 3.4.2 Elliptical orbits . 19 4 Asteroid shapes and gravity fields 21 4.1 Polyhedron Modelling . 21 4.1.1 Implementation . 23 4.2 Spherical Harmonics . 24 4.2.1 Implementation . 26 4.2.2 Implementation of the associated Legendre polynomials . 27 4.3 Triaxial Ellipsoids . 28 4.3.1 Implementation of method . 29 4.3.2 Validation . 30 5 Perturbing forces near asteroids 34 5.1 Third-body perturbations . 34 5.1.1 Implementation of the third-body perturbations . 36 5.2 Solar Radiation Pressure . 36 5.2.1 The effect of solar radiation pressure . 38 5.2.2 Implementation of the Solar Radiation Pressure . 40 6 About the stability disturbing effects near asteroids 42 ii CONTENTS 7 Integrators 44 7.1 Runge-Kutta Methods . 44 7.1.1 Runge-Kutta fourth-order integrator . 45 7.1.2 Runge-Kutta-Fehlberg Method .
    [Show full text]
  • Asteroid Family Identification 613
    Bendjoya and Zappalà: Asteroid Family Identification 613 Asteroid Family Identification Ph. Bendjoya University of Nice V. Zappalà Astronomical Observatory of Torino Asteroid families have long been known to exist, although only recently has the availability of new reliable statistical techniques made it possible to identify a number of very “robust” groupings. These results have laid the foundation for modern physical studies of families, thought to be the direct result of energetic collisional events. A short summary of the current state of affairs in the field of family identification is given, including a list of the most reliable families currently known. Some likely future developments are also discussed. 1. INTRODUCTION calibrate new identification methods. According to the origi- nal papers published in the literature, Brouwer (1951) used The term “asteroid families” is historically linked to the a fairly subjective criterion to subdivide the Flora family name of the Japanese researcher Kiyotsugu Hirayama, who delineated by Hirayama. Arnold (1969) assumed that the was the first to use the concept of orbital proper elements to asteroids are dispersed in the proper-element space in a identify groupings of asteroids characterized by nearly iden- Poisson distribution. Lindblad and Southworth (1971) cali- tical orbits (Hirayama, 1918, 1928, 1933). In interpreting brated their method in such a way as to find good agree- these results, Hirayama made the hypothesis that such a ment with Brouwer’s results. Carusi and Massaro (1978) proximity could not be due to chance and proposed a com- adjusted their method in order to again find the classical mon origin for the members of these groupings.
    [Show full text]
  • One Team from This State Was the First Your Writer Ever Lost to at a National Tournament
    1. (Meta) One team from this state was the first your writer ever lost to at a National tournament. One ​ coach from this state created (^) an A-set tournament solely in order to qualify his team for HSNCT ​ after proposing an all-female tournament, Title IX Bowl. A 2009 cheating scandal in (+) this state ​ involved a team’s gmail account being used by its treasurer to access SCT questions, which he then used to defeat such powerhouse teams as Vanderbilt B. A standing rule (*) of ILQBM bans memes ​ from this state, and the top-ranked team from this state lost to their own B team at New Trier Varsity. For ten points, name this state home to teams such as Northview and Chattahoochee. Answer: Georgia ​ Bonus: Name the following about other cheaters. [10] This Windhaven Park E player won a tournament with a 66/18/3 statline after improperly accessing IS-164 questions. He did not demonstrate his knowledge via skype due to a sudden attack of buzzer shyness. Answer: Ethan McBride ​ [10] (pseudonyms acceptable) This early Ohioan cheater notably created two sock puppet forum accounts pretending to be his friend and his friend’s mother to attest to his good character and mask the fact that he played a HS tournament despite being in college. Answer: Basileus (accept dafirenze, Paul Harold, Nancydf64) ​ ​ ​ ​ ​ ​ ​ ​ [10] This most notorious of quizbowl cheaters was referred to as “the grand vizier of fuckfaces” in a hate thread dedicated to him. He won three ICTs for Harvard, all of which were rescinded. Answer: Andy Watkins ​ 2.
    [Show full text]
  • PPARC Cassinni
    Seasons on Saturn Sightseeing What is en-route toSaturn Cassini Huygens was launched Cassini in 1997 on a Titan IV/Centaur Huygens? rocket. In order to build up the energy needed to reach distant Saturn, the spacecraft followed a Cassini Huygens is an international space mission spiral route past the Earth, Venus to explore Saturn and its largest moon, Titan. The and Jupiter. As it swung by each mission is made up of NASA’s Cassini orbiter and planet, it picked up speed using a the European Space Agency’s Huygens probe. technique called “gravity assist”. Cassini Huygens launch Taking this roundabout route meant that The mission is named after two 17th Cassini could carry out science investigations Century astronomers: Jean Dominique during its journey. The spacecraft’s ISS cameras Cassini, the discoverer of four of took spectacular images of the Moon during an Saturn’s orbit Saturn’s moons, and Christiaan Huygens, Earth flyby in 1999 and picked out Asteroid Jupiter who discovered Titan and realised that 2685 Masursky from a distance of 1.6 million Earth’s orbit the “ears” Galileo had observed either kilometres – good practice for its task of Jupiter’s orbit Between November 2000 and February 2001, Cassini teamed up side of Saturn were actually rings. finding new moons at Saturn. Venus’ orbit with NASA’s Galileo mission to study Jupiter. Besides taking some beautiful pictures of the gas giant, Cassini found that Jupiter’s Jean Dominique Cassini Christian Huygens Cassini’s trajectory magnetic field is lopsided, leaks high-energy particles and changes size as space weather events pass by.
    [Show full text]
  • Zákryt Jasné Hvězdy Saturnem
    Zákrytová a astrometrická sekce ČAS leden 2006 (1) Zajímavosti: NENECHTE SI UJÍT Zákryt jasné hv ězdy Saturnem 25. ledna 2006 ve čer mimo jiné i Evropu čeká velice zajímavá ř ě Č podívaná. Planeta Saturn okrášlená prstencem p řejde p řes relativn ě Situace, jak vypadá p i pohledu z hv zdy. asy udávané v malé vložené ě ě č jasnou hv ězdu a ze Zem ě budeme mít možnost sledovat nejen zákryt tabulce jsou platné pro Mainz (N mecko). Pro jiná místa v Evrop jsou asy v tabulce za článkem. stálice vlastní planetou, ale i její poblikávání za jednotlivými prstenci. Velice zajímavé bude jist ě pokusit se celý úkaz nahrát speciálními videokamerami v ohnisku dlouhofokálních teleobjektiv ů či dalekohled ů. Zajímavá a nevšední podívaná však čeká jist ě i na ty, kdo se na úkaz budou chtít pouze vizuáln ě podívat. Lednový zákryt hv ězdy Saturnem je jist ě zajímavou údálostí, ale nemá p říliš velkou publicitu. Úkaz bude viditelný z Evropy, Afriky a Asie. P řičemž z jižní Afriky bude možno sledovat pouze zákryty hv ězdy prstenci a zákryt vlastní planetou tuto oblast již mine. U nás, ve st řední Evrop ě, by úkaz m ěl za čít v 18:45 UT, kdy se hv ězda dostane k vn ějšímu okraji soustavy prstenc ů. V tom čase bude planeta již dostate čně vysoko nad východním obzorem (h=26°; A=92°). Zákryt Pr ůchod hv ězdy oblastí systému satelit ů planety Saturn p ři pohledu ze Země kotou čkem planety pak nastane v intervalu 20:08 UT (D – vstup) až 20:49 (R – (geocentrický pohled).
    [Show full text]
  • A Low Density of 0.8 G Cm-3 for the Trojan Binary Asteroid 617 Patroclus
    Publisher: NPG; Journal: Nature:Nature; Article Type: Physics letter DOI: 10.1038/nature04350 A low density of 0.8 g cm−3 for the Trojan binary asteroid 617 Patroclus Franck Marchis1, Daniel Hestroffer2, Pascal Descamps2, Jérôme Berthier2, Antonin H. Bouchez3, Randall D. Campbell3, Jason C. Y. Chin3, Marcos A. van Dam3, Scott K. Hartman3, Erik M. Johansson3, Robert E. Lafon3, David Le Mignant3, Imke de Pater1, Paul J. Stomski3, Doug M. Summers3, Frederic Vachier2, Peter L. Wizinovich3 & Michael H. Wong1 1Department of Astronomy, University of California, 601 Campbell Hall, Berkeley, California 94720, USA. 2Institut de Mécanique Céleste et de Calculs des Éphémérides, UMR CNRS 8028, Observatoire de Paris, 77 Avenue Denfert-Rochereau, F-75014 Paris, France. 3W. M. Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, Hawaii 96743, USA. The Trojan population consists of two swarms of asteroids following the same orbit as Jupiter and located at the L4 and L5 stable Lagrange points of the Jupiter–Sun system (leading and following Jupiter by 60°). The asteroid 617 Patroclus is the only known binary Trojan1. The orbit of this double system was hitherto unknown. Here we report that the components, separated by 680 km, move around the system’s centre of mass, describing a roughly circular orbit. Using this orbital information, combined with thermal measurements to estimate +0.2 −3 the size of the components, we derive a very low density of 0.8 −0.1 g cm . The components of 617 Patroclus are therefore very porous or composed mostly of water ice, suggesting that they could have been formed in the outer part of the Solar System2.
    [Show full text]
  • Aqueous Alteration on Main Belt Primitive Asteroids: Results from Visible Spectroscopy1
    Aqueous alteration on main belt primitive asteroids: results from visible spectroscopy1 S. Fornasier1,2, C. Lantz1,2, M.A. Barucci1, M. Lazzarin3 1 LESIA, Observatoire de Paris, CNRS, UPMC Univ Paris 06, Univ. Paris Diderot, 5 Place J. Janssen, 92195 Meudon Pricipal Cedex, France 2 Univ. Paris Diderot, Sorbonne Paris Cit´e, 4 rue Elsa Morante, 75205 Paris Cedex 13 3 Department of Physics and Astronomy of the University of Padova, Via Marzolo 8 35131 Padova, Italy Submitted to Icarus: November 2013, accepted on 28 January 2014 e-mail: [email protected]; fax: +33145077144; phone: +33145077746 Manuscript pages: 38; Figures: 13 ; Tables: 5 Running head: Aqueous alteration on primitive asteroids Send correspondence to: Sonia Fornasier LESIA-Observatoire de Paris arXiv:1402.0175v1 [astro-ph.EP] 2 Feb 2014 Batiment 17 5, Place Jules Janssen 92195 Meudon Cedex France e-mail: [email protected] 1Based on observations carried out at the European Southern Observatory (ESO), La Silla, Chile, ESO proposals 062.S-0173 and 064.S-0205 (PI M. Lazzarin) Preprint submitted to Elsevier September 27, 2018 fax: +33145077144 phone: +33145077746 2 Aqueous alteration on main belt primitive asteroids: results from visible spectroscopy1 S. Fornasier1,2, C. Lantz1,2, M.A. Barucci1, M. Lazzarin3 Abstract This work focuses on the study of the aqueous alteration process which acted in the main belt and produced hydrated minerals on the altered asteroids. Hydrated minerals have been found mainly on Mars surface, on main belt primitive asteroids and possibly also on few TNOs. These materials have been produced by hydration of pristine anhydrous silicates during the aqueous alteration process, that, to be active, needed the presence of liquid water under low temperature conditions (below 320 K) to chemically alter the minerals.
    [Show full text]