DOCSLIB.ORG

Convex-Profile Inversion of Asteroid Lightcurves: Theory and Applications

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Convex-Profile Inversion of Asteroid Lightcurves: Theory and Applications ICARUS 75, 30-63 (1988) Convex-Profile Inversion of Asteroid Lightcurves: Theory and Applications STEVEN J. OSTRO Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 ROBERT CONNELLY Department of Mathematics, Cornell Uniuersity, Ithaca, New York 14853 AND MARK DOROGI' Department of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 Received October 8, 1987; revised December 8, 1987 Convex-profile inversion, introduced by S. J. Ostro and R. Connelly (1984, Icarus 57, 443-463), is reformulated, extended, and calibrated as a theory for physical interpreta- tion of an asteroid's lightcurve and then is used to constrain the shapes of selected asteroids. Under ideal conditions, one can obtain the asteroid's "mean cross section" C, a convex profile equal to the average of the convex envelopes of all the surface contours parallel to the equatorial plane. C is a unique, rigorously defined, two-dimensional average of the three-dimensional shape and constitutes optimal extraction of shape information from a nonopposition lightcurve. For a lightcurve obtained at opposition, C's odd harmonics are not accessible, but one can estimate the asteroid's symmetrized mean cross section, Cs. To convey visually the physical meaning of the mean cross sections, we show C and Cs calculated numerically for a regular convex shape and for an irregular, nonconvex shape. The ideal conditions for estimating C from a lightcurve are Condition GEO, that the scattering is uniform and geometric; Condition EVIG, that the viewing-illumination geometry is equatorial; Condition CONVEX, that all of the aster- oid's surface contours parallel to the equatorial plane are convex; and Condition PHASE, that the solar phase angle 4 * 0. Condition CONVEX is irrelevant for estima- tion of Cs. Definition of a rotation- and scale-invariant measure of the distance, A2, between two profiles permits quantitative comparison of the profiles' shapes. Useful descriptors of a profile's shape are its noncircularity, 12c, defined as the distance of the profile from a circle, and the ratio ,6* of the maximum and minimum values of the profile's breadth function 13(0), where 0 is rotational phase. C and Cs have identical breadth functions. At opposition, under Conditions EVIG and GEO, (i) the lightcurve is equal to C's breadth function, and (ii) ,8* = 10° m, where Am is the lightcurve peak-to- valley amplitude in magnitudes; this is the only situation where Am has a unique physical interpretation. An estimate C of C (or Cs of Cs) can be distorted if the applicable ideal conditions are violated. We present results of simulations designed to calibrate the na- ture, severity, and predictability of such systematic error. Distortion introduced by viola- tion of Condition EVIG depends on 4, on the asteroid-centered declinations Ss and SE of the Sun and Earth, and on the asteroid's three-dimensional shape. Violations of Condi- tion EVIG on the order of 100 appear to have little effect for convex, axisymmetric Current address: Philips ECG, 50 Johnston St., Seneca Falls, NY 13148. 30 0019-1035/88 $3.00 Copyrighte 1988by Academic Press, Inc. All nghts of reproduction in any form reserved. ASTEROID LIGHTCURVE INVERSION 3 1 shapes. Errors arising from violation of Condition GEO have been studied by generating lightcurves for model asteroids having known mean cross sections and obeying Hapke's photometric function, inverting the lightcurves, and comparing C to C. The distance of C from C depends on k and rarely is negligible, but values of 12, and ,8* for C resemble those of C rather closely for a range of solar phase angles (i - 20° ± 100) generally accessible for most asteroids. Opportunities for reliable estimation of Cs far outnumber those for C. We have examined how lightcurve noise and rotational-phase sampling rate propagate into statistical error in C and offer guidelines for acquisition of lightcurves targeted for convex-profile inversion. Estimates of C and/or Cs are presented for selected asteroids, along with profile shape descriptors and goodness-of-fit statistics for the in- verted lightcurves. For 15 Eunomia and 19 Fortuna, we calculate weighted estimates of C from lightcurves taken at different solar phase angles. C 1988 Academic Press, Inc. 1. INTRODUCTION present a comprehensive conceptual foun- dation for the physical interpretation of One of an asteroid's most fundamental asteroid lightcurves. This foundation en- attributes is its shape, and lightcurves pro- compasses calibration and application of vide the only source of shape information convex-profile inversion as well as estab- for most asteroids. However, the functional lished principles from the oldest lightcurve form of a lightcurve is determined by the literature, so let us begin with a review of viewing/illumination geometry and the as- essential background material in which we teroid's light-scattering properties as well emphasize the progression of logic which as by its shape, and lightcurves offer less has led to convex-profile inversion. powerful shape constraints than do tech- niques that resolve asteroids spatially. Os- tro and Connelly (1984) introduced a new 11. HISTORICAL BACKGROUND AND REVIEW approach called convex-profile inversion to OF RECENT WORK using a lightcurve to constrain an asteroid's A general statement of the lightcurve in- shape, demonstrating that any lightcurve version problem is "Given that a lightcurve can be inverted to yield a convex profile is determined by asteroid shape, surface that, under certain ideal conditions, repre- scattering properties, and viewing/illumina- sents a certain two-dimensional average of tion geometry, how, if at all, can we isolate the asteroid's three-dimensional shape. The these effects and obtain physically interest- ideal conditions include geometric scatter- ing information about the asteroid?" In a ing and equatorial viewing/illumination ge- classic paper, H. N. Russell (1906) offered ometry and will rarely be satisfied exactly the first analysis of this problem, investigat- for actual lightcurves, so the derived shape ing in fine detail the information content of constraints will usually contain systematic lightcurves taken close to opposition, i.e., error. with the solar phase angle 0 0°. He sum- Therefore, while convex-profile inver- marized his results as follows: If an asteroid sion can help to optimize extraction of has been observed at opposition in all parts shape information, proper application of of its orbit: the technique demands an understanding of (RI) "We can determine by inspection of systematic (as well as statistical) sources of its light-curves whether or not they can be uncertainty. Two objectives of this paper accounted for by its rotation alone, and, if are to explore these effects at some length so, whether the asteroid (a) has an absorb- and then, with a better feel for error ing atmosphere, (b) is not of a convex2 sources, to use convex-profile inversion to constrain the shapes of selected asteroids. 2 An object is convex if the straight line connecting A third, more general, objective is to any two points on the boundary is inside the boundary. 32 OSTRO, CONNELLY, AND DOROGI form, (c) has a spotted surface, or whether the asteroid's shape is not convex. How- these hypotheses are unnecessary." ever, as Russell proved, it is impossible to (R2) "It is always possible (theoretically) separate the effects of albedo variation to determine the position of the asteroid's from effects of surface curvature, so nei- equator, (except that the sign of the inclina- ther the light-scattering properties nor the tion remains unknown)." That is, we can shape can be modeled uniquely. Hence, find the line of equinoxes, of intersection apart from testing the convexity hypothe- between the equatorial and orbital planes, sis, the utility of lightcurves as sources of and the size of the angle between those shape information seemed virtually nil. planes. More than half a century after Russell's (R3) "It is quite impossible to determine treatise, photoelectric photometry and po- the [three-dimensional] shape of the aster- larimetry dramatically changed the empiri- oid. If any continuous convex form is possi- cal setting for lightcurve interpretation, ble, all such forms are possible." demonstrating that with a few notable ex- (R4) "In this case we may assume any ceptions the forms of most broadband opti- such form, and then determine a distribu- cal lightcurves seem less sensitive to sur- tion of brightness on its surface which will face heterogeneity than to gross shape. account for the observed light-curves. This Moreover, laboratory experiments and the- can usually be done in an infinite variety of oretical studies disclosed that geometric ways. " scattering is likely to be a good approxima- (R5) "The consideration of the light- tion for asteroids viewed close to opposi- curve of a planet at phases remote from op- tion (e.g., French and Veverka 1983) but position may aid in determining the mark- that the validity of this approximation dete- ings on its surface, but cannot help us find riorates with increasing solar phase angle. its [three-dimensional] shape." Thus, in the absence of evidence to the con- Despite Russell's skepticism toward trary, the premise that the scattering is uni- prospects for using lightcurves to find an form and geometric has been the starting asteroid's three-dimensional shape, he did point for nearly all efforts to interpret light- describe how to test certain hypotheses curves physically (e.g., Burns and Tedesco about shape, scattering law, and albedo dis- 1979, Harris 1986). tribution. For example, suppose we have Many researchers further constrain the found the asteroid's line of equinoxes (R2) lightcurve inversion problem by assuming a and obtained an "equatorial" opposition simple a priori shape. The usual choice is a lightcurve. Russell showed that such a triaxial ellipsoid, whose shape is com- lightcurve's Fourier series cannot have odd pletely described by the ratios bla and cla, harmonics higher than the first if the scat- with a - b - c the semiaxis lengths.
Load more

Recommended publications
  • 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]
  • The Handbook of the British Astronomical Association
    THE HANDBOOK OF THE BRITISH ASTRONOMICAL ASSOCIATION 2012 Saturn’s great white spot of 2011 2011 October ISSN 0068-130-X CONTENTS CALENDAR 2012 . 2 PREFACE. 3 HIGHLIGHTS FOR 2012. 4 SKY DIARY . .. 5 VISIBILITY OF PLANETS. 6 RISING AND SETTING OF THE PLANETS IN LATITUDES 52°N AND 35°S. 7-8 ECLIPSES . 9-15 TIME. 16-17 EARTH AND SUN. 18-20 MOON . 21 SUN’S SELENOGRAPHIC COLONGITUDE. 22 MOONRISE AND MOONSET . 23-27 LUNAR OCCULTATIONS . 28-34 GRAZING LUNAR OCCULTATIONS. 35-36 PLANETS – EXPLANATION OF TABLES. 37 APPEARANCE OF PLANETS. 38 MERCURY. 39-40 VENUS. 41 MARS. 42-43 ASTEROIDS AND DWARF PLANETS. 44-60 JUPITER . 61-64 SATELLITES OF JUPITER . 65-79 SATURN. 80-83 SATELLITES OF SATURN . 84-87 URANUS. 88 NEPTUNE. 89 COMETS. 90-96 METEOR DIARY . 97-99 VARIABLE STARS . 100-105 Algol; λ Tauri; RZ Cassiopeiae; Mira Stars; eta Geminorum EPHEMERIDES OF DOUBLE STARS . 106-107 BRIGHT STARS . 108 ACTIVE GALAXIES . 109 INTERNET RESOURCES. 110-111 GREEK ALPHABET. 111 ERRATA . 112 Front Cover: Saturn’s great white spot of 2011: Image taken on 2011 March 21 00:10 UT by Damian Peach using a 356mm reflector and PGR Flea3 camera from Selsey, UK. Processed with Registax and Photoshop. British Astronomical Association HANDBOOK FOR 2012 NINETY-FIRST YEAR OF PUBLICATION BURLINGTON HOUSE, PICCADILLY, LONDON, W1J 0DU Telephone 020 7734 4145 2 CALENDAR 2012 January February March April May June July August September October November December Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day Day of of of of of of of of of of of of of of of of of of of of of of of of of Month Week Year Week Year Week Year Week Year Week Year Week Year Week Year Week Year Week Year Week Year Week Year Week Year 1 Sun.
    [Show full text]
  • The Minor Planet Bulletin, It Is a Pleasure to Announce the Appointment of Brian D
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 33, NUMBER 1, A.D. 2006 JANUARY-MARCH 1. LIGHTCURVE AND ROTATION PERIOD Observatory (Observatory code 926) near Nogales, Arizona. The DETERMINATION FOR MINOR PLANET 4006 SANDLER observatory is located at an altitude of 1312 meters and features a 0.81 m F7 Ritchey-Chrétien telescope and a SITe 1024 x 1024 x Matthew T. Vonk 24 micron CCD. Observations were conducted on (UT dates) Daniel J. Kopchinski January 29, February 7, 8, 2005. A total of 37 unfiltered images Amanda R. Pittman with exposure times of 120 seconds were analyzed using Canopus. Stephen Taubel The lightcurve, shown in the figure below, indicates a period of Department of Physics 3.40 ± 0.01 hours and an amplitude of 0.16 magnitude. University of Wisconsin – River Falls 410 South Third Street Acknowledgements River Falls, WI 54022 [email protected] Thanks to Michael Schwartz and Paulo Halvorcem for their great work at Tenagra Observatory. (Received: 25 July) References Minor planet 4006 Sandler was observed during January Schmadel, L. D. (1999). Dictionary of Minor Planet Names. and February of 2005. The synodic period was Springer: Berlin, Germany. 4th Edition. measured and determined to be 3.40 ± 0.01 hours with an amplitude of 0.16 magnitude. Warner, B. D. and Alan Harris, A. (2004) “Potential Lightcurve Targets 2005 January – March”, www.minorplanetobserver.com/ astlc/targets_1q_2005.htm Minor planet 4006 Sandler was discovered by the Russian astronomer Tamara Mikhailovna Smirnova in 1972. (Schmadel, 1999) It orbits the sun with an orbit that varies between 2.058 AU and 2.975 AU which locates it in the heart of the main asteroid belt.
    [Show full text]
  • A Radar Survey of Main-Belt Asteroids: Arecibo Observations of 55 Objects During 1999–2003
    Icarus 186 (2007) 126–151 www.elsevier.com/locate/icarus A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999–2003 Christopher Magri a,∗, Michael C. Nolan b,StevenJ.Ostroc, Jon D. Giorgini d a University of Maine at Farmington, 173 High Street—Preble Hall, Farmington, ME 04938, USA b Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612, USA c 300-233, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA d 301-150, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA Received 3 June 2006; revised 10 August 2006 Available online 24 October 2006 Abstract We report Arecibo observations of 55 main-belt asteroids (MBAs) during 1999–2003. Most of our targets had not been detected previously with radar, so these observations more than double the number of radar-detected MBAs. Our bandwidth estimates constrain our targets’ pole directions in a manner that is geometrically distinct from optically derived constraints. We present detailed statistical analyses of the disk-integrated properties (radar albedo and circular polarization ratio) of the 84 MBAs observed with radar through March 2003; all of these observations are summarized in the online supplementary information. Certain conclusions reached in previous studies are strengthened: M asteroids have higher mean radar albedos and a wider range of albedos than do other MBAs, suggesting that both metal-rich and metal-poor M-class objects exist; and C- and S-class MBAs have indistinguishable radar albedo distributions, suggesting that most S-class objects are chondritic. Also in accord with earlier results, there is evidence that primitive asteroids from outside the C taxon (F, G, P, and D) are not as radar-bright as C and S objects, but a convincing statistical test must await larger sample sizes.
    [Show full text]
  • The Minor Planet Bulletin Is Open to Papers on All Aspects of 6500 Kodaira (F) 9 25.5 14.8 + 5 0 Minor Planet Study
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 32, NUMBER 3, A.D. 2005 JULY-SEPTEMBER 45. 120 LACHESIS – A VERY SLOW ROTATOR were light-time corrected. Aspect data are listed in Table I, which also shows the (small) percentage of the lightcurve observed each Colin Bembrick night, due to the long period. Period analysis was carried out Mt Tarana Observatory using the “AVE” software (Barbera, 2004). Initial results indicated PO Box 1537, Bathurst, NSW, Australia a period close to 1.95 days and many trial phase stacks further [email protected] refined this to 1.910 days. The composite light curve is shown in Figure 1, where the assumption has been made that the two Bill Allen maxima are of approximately equal brightness. The arbitrary zero Vintage Lane Observatory phase maximum is at JD 2453077.240. 83 Vintage Lane, RD3, Blenheim, New Zealand Due to the long period, even nine nights of observations over two (Received: 17 January Revised: 12 May) weeks (less than 8 rotations) have not enabled us to cover the full phase curve. The period of 45.84 hours is the best fit to the current Minor planet 120 Lachesis appears to belong to the data. Further refinement of the period will require (probably) a group of slow rotators, with a synodic period of 45.84 ± combined effort by multiple observers – preferably at several 0.07 hours. The amplitude of the lightcurve at this longitudes. Asteroids of this size commonly have rotation rates of opposition was just over 0.2 magnitudes.
    [Show full text]
  • INPOP08, a 4-D Planetary Ephemeris: from Asteroid and Time-Scale Computations to ESA Mars Express and Venus Express Contributions
    A&A 507, 1675–1686 (2009) Astronomy DOI: 10.1051/0004-6361/200911755 & c ESO 2009 Astrophysics INPOP08, a 4-D planetary ephemeris: from asteroid and time-scale computations to ESA Mars Express and Venus Express contributions A. Fienga1,2, J. Laskar1,T.Morley3,H.Manche1, P. Kuchynka1, C. Le Poncin-Lafitte4, F. Budnik3, M. Gastineau1, and L. Somenzi1,2 1 Astronomie et Systèmes Dynamiques, IMCCE-CNRS UMR8028, 77 Av. Denfert-Rochereau, 75014 Paris, France 2 Observatoire de Besançon, CNRS UMR6213, 41bis Av. de l’Observatoire, 25000 Besançon, France e-mail: [email protected] 3 ESOC, Robert-Bosch-Str. 5, Darmstadt 64293, Germany 4 SYRTE, CNRS UMR8630, Observatoire de Paris, 77 Av. Denfert-Rochereau, 75014 Paris, France Received 31 January 2009 / Accepted 24 August 2009 ABSTRACT The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besançon Observatory is presented. INPOP08 is a 4-dimension ephemeris since it provides positions and velocities of planets and the relation between Terrestrial Time and Barycentric Dynamical Time. Investigations to improve the modeling of asteroids are described as well as the new sets of observations used for the fit of INPOP08. New observations provided by the European Space Agency deduced from the tracking of the Mars Express and Venus Express missions are presented as well as the normal point deduced from the Cassini mission. We show importance of these observations in the fit of INPOP08, especially in terms of Venus, Saturn and Earth-Moon barycenter orbits. Key words. ephemerides – astrometry – time – minor planets, asteroids – solar system: general – space vehicules 1.
    [Show full text]
  • The Planetary and Lunar Ephemeris DE 421
    IPN Progress Report 42-178 • August 15, 2009 The Planetary and Lunar Ephemeris DE 421 William M. Folkner,* James G. Williams,† and Dale H. Boggs† The planetary and lunar ephemeris DE 421 represents updated estimates of the orbits of the Moon and planets. The lunar orbit is known to submeter accuracy through fitting lunar laser ranging data. The orbits of Venus, Earth, and Mars are known to subkilometer accu- racy. Because of perturbations of the orbit of Mars by asteroids, frequent updates are needed to maintain the current accuracy into the future decade. Mercury’s orbit is determined to an accuracy of several kilometers by radar ranging. The orbits of Jupiter and Saturn are determined to accuracies of tens of kilometers as a result of spacecraft tracking and modern ground-based astrometry. The orbits of Uranus, Neptune, and Pluto are not as well deter- mined. Reprocessing of historical observations is expected to lead to improvements in their orbits in the next several years. I. Introduction The planetary and lunar ephemeris DE 421 is a significant advance over earlier ephemeri- des. Compared with DE 418, released in July 2007,1 the DE 421 ephemeris includes addi- tional data, especially range and very long baseline interferometry (VLBI) measurements of Mars spacecraft; range measurements to the European Space Agency’s Venus Express space- craft; and use of current best estimates of planetary masses in the integration process. The lunar orbit is more robust due to an expanded set of lunar geophysical solution parameters, seven additional months of laser ranging data, and complete convergence.
    [Show full text]
  • Secular Spin Dynamics of Inner Main-Belt Asteroids
    ARTICLE IN PRESS YICAR:7941 JID:YICAR AID:7941 /FLA [m5+; v 1.60; Prn:1/06/2006; 9:53] P.1 (1-28) Icarus ••• (••••) •••–••• www.elsevier.com/locate/icarus Secular spin dynamics of inner main-belt asteroids D. Vokrouhlický ∗,1, D. Nesvorný, W.F. Bottke Southwest Research Institute, 1050 Walnut St., Suite 400, Boulder, CO 80302, USA Received 29 December 2005; revised 6 April 2006 Abstract Understanding the evolution of asteroid spin states is challenging work, in part because asteroids have a variety of orbits, shapes, spin states, and collisional histories but also because they are strongly influenced by gravitational and non-gravitational (YORP) torques. Using efficient numerical models designed to investigate asteroid orbit and spin dynamics, we study here how several individual asteroids have had their spin states modified over time in response to these torques (i.e., 951 Gaspra, 60 Echo, 32 Pomona, 230 Athamantis, 105 Artemis). These test cases which sample semimajor axis and inclination space in the inner main belt, were chosen as probes into the large parameter space described above. The ultimate goal is to use these data to statistically characterize how all asteroids in the main belt population have reached their present-day spin states. We found that the spin dynamics of prograde-rotating asteroids in the inner main belt is generally less regular than that of the retrograde- rotating ones because of numerous overlapping secular spin–orbit resonances. These resonances strongly affect the spin histories of all bodies, while those of small asteroids (40 km) are additionally influenced by YORP torques. In most cases, gravitational and non-gravitational torques cause asteroid spin axis orientations to vary widely over short (1 My) timescales.
    [Show full text]
  • INPOP08, a 4-D Planetary Ephemeris: from Asteroid and Time-Scale Computations to ESA Mars Express and Venus Express Contributions
    Astronomy & Astrophysics manuscript no. inpop08.2.v3c June 10, 2009 (DOI: will be inserted by hand later) INPOP08, a 4-D planetary ephemeris: From asteroid and time-scale computations to ESA Mars Express and Venus Express contributions. A. Fienga1;2, J. Laskar1, T. Morley3, H. Manche1, P. Kuchynka1, C. Le Poncin-Lafitte4, F. Budnik3, M. Gastineau1, and L. Somenzi1;2 1 Astronomie et Syst`emesDynamiques, IMCCE-CNRS UMR8028, 77 Av. Denfert-Rochereau, 75014 Paris, France 2 Observatoire de Besan¸con,CNRS UMR6213, 41bis Av. de l'Observatoire, 25000 Besan¸con,France 3 ESOC, Robert-Bosch-Str. 5, Darmstadt, D-64293 Germany 4 SYRTE, CNRS UMR8630, Observatoire de Paris, 77 Av. Denfert-Rochereau, 75014 Paris, France June 10, 2009 Abstract. The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besan¸conObservatory is presented here. INPOP08 is a 4-dimension ephemeris since it provides to users positions and velocities of planets and the relation between TT and TDB. Investigations leading to improve the modeling of asteroids are described as well as the new sets of observations used for the fit of INPOP08. New observations provided by the European Space Agency (ESA) deduced from the tracking of the Mars Express (MEX) and Venus Express (VEX) missions are presented as well as the normal point deduced from the Cassini mission. We show the huge impact brought by these observations in the fit of INPOP08, especially in terms of Venus, Saturn and Earth-Moon barycenter orbits. Key words. celestial mechanics - ephemerides 1. Introduction ephemeris. The basic idea is to provide to users po- sitions and velocities of Solar System celestial objects, Since the first release, INPOP06, of the plane- and also, time ephemerides relating the Terrestrial time- tary ephemerides developed at Paris and Besan¸con scale, TT, and the time argument of INPOP, the so-called Observatories, (Fienga et al.
    [Show full text]
  • Cumulative Index to Volumes 1-45
    The Minor Planet Bulletin Cumulative Index 1 Table of Contents Tedesco, E. F. “Determination of the Index to Volume 1 (1974) Absolute Magnitude and Phase Index to Volume 1 (1974) ..................... 1 Coefficient of Minor Planet 887 Alinda” Index to Volume 2 (1975) ..................... 1 Chapman, C. R. “The Impossibility of 25-27. Index to Volume 3 (1976) ..................... 1 Observing Asteroid Surfaces” 17. Index to Volume 4 (1977) ..................... 2 Tedesco, E. F. “On the Brightnesses of Index to Volume 5 (1978) ..................... 2 Dunham, D. W. (Letter regarding 1 Ceres Asteroids” 3-9. Index to Volume 6 (1979) ..................... 3 occultation) 35. Index to Volume 7 (1980) ..................... 3 Wallentine, D. and Porter, A. Index to Volume 8 (1981) ..................... 3 Hodgson, R. G. “Useful Work on Minor “Opportunities for Visual Photometry of Index to Volume 9 (1982) ..................... 4 Planets” 1-4. Selected Minor Planets, April - June Index to Volume 10 (1983) ................... 4 1975” 31-33. Index to Volume 11 (1984) ................... 4 Hodgson, R. G. “Implications of Recent Index to Volume 12 (1985) ................... 4 Diameter and Mass Determinations of Welch, D., Binzel, R., and Patterson, J. Comprehensive Index to Volumes 1-12 5 Ceres” 24-28. “The Rotation Period of 18 Melpomene” Index to Volume 13 (1986) ................... 5 20-21. Hodgson, R. G. “Minor Planet Work for Index to Volume 14 (1987) ................... 5 Smaller Observatories” 30-35. Index to Volume 15 (1988) ................... 6 Index to Volume 3 (1976) Index to Volume 16 (1989) ................... 6 Hodgson, R. G. “Observations of 887 Index to Volume 17 (1990) ................... 6 Alinda” 36-37. Chapman, C. R. “Close Approach Index to Volume 18 (1991) ..................
    [Show full text]
  • Smartstar Solar 60 GOTO Telescope Instruction Manual
    SmartStar® Solar 60 GOTO Telescope Instruction Manual For Products #8506, #8507, #8806 & #8807 1 Table of Content Table of Content ............................................................................................................................. 2 1. SmarStar® Solar 60TM Overview ................................................................................................ 4 1.1. SmartStar® Solar 60TM Features .......................................................................................... 4 1.2. SmartStar® Solar 60TM Assembly Terms ............................................................................. 6 2. Telescope Assembly ................................................................................................................... 7 3. GoToNova® 8405 Hand Controller ............................................................................................ 9 3.1. Key Description ................................................................................................................... 9 3.2. The LCD Screen .................................................................................................................. 9 4. Getting Started .......................................................................................................................... 11 4.1. Getting Familiar with Telescope ........................................................................................ 11 4.1.1. Using the telescope ....................................................................................................
    [Show full text]
  • Download Full Issue
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 47, NUMBER 1, A.D. 2020 JANUARY-MARCH 1. SECTION NEWS: COLLABORATIVE ASTEROID PHOTOMETRY FOR STAFFING CHANGES FOR ASTEROID 2051 CHANG THE MINOR PLANET BULLETIN Alessandro Marchini Frederick Pilcher Astronomical Observatory, DSFTA - University of Siena (K54) Minor Planets Section Recorder Via Roma 56, 53100 - Siena, ITALY [email protected] [email protected] One staffing change and one staffing addition for The Minor Planet Bulletin are announced effective with this issue. Riccardo Papini, Massimo Banfi, Fabio Salvaggio Wild Boar Remote Observatory (K49) MPB Distributor Derald Nye is now retired from his 37 years of San Casciano in Val di Pesa (FI), ITALY service to the Minor Planets Bulletin. Derald stepped in to service at the time the MPB made its transition from the original Editor Melissa N. Hayes-Gehrke, Eric Yates and Section founder, Richard G. Hodgson. As Derald reflected in Department of Astronomy, University of Maryland a short essay written in MPB 40, page 53 (2013), the Distributor College Park, MD, USA 20740 position was the longest job he ever held, having retired from being a programmer for 30 years with IBM. (Work for IBM (Received: 2019 October 15) included programming for the space program.) At its peak, Derald was managing nearly 200 subscriptions. That number dropped to Photometric observations of this main-belt asteroid were the dozen or so libraries maintaining a permanent collection conducted in order to determine its rotation period. The following the MPB transitioning to becoming an on-line electronic authors found a synodic rotation period of 12.013 ± journal with limited printing.
    [Show full text]