DOCSLIB.ORG

The British Astronomical Association Handbook 2018

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

THE HANDBOOK OF THE BRITISH ASTRONOMICAL ASSOCIATION 2018 2017 October ISSN 0068–130–X CONTENTS PREFACE . 2 HIGHLIGHTS FOR 2018 . 3 SKY DIARY . .. 4-5 CALENDAR 2018 . 6 SUN . 7-9 ECLIPSES . 10-15 APPEARANCE OF PLANETS . 16 VISIBILITY OF PLANETS . 17 RISING AND SETTING OF THE PLANETS IN LATITUDES 52°N AND 35°S . 18-19 PLANETS – Explanatin of Tables . 20 ELEMENTS OF PLANETARY ORBITS . 21 MERCURY . 22-23 VENUS . 24 EARTH . 25 MOON . 25 LUNAR LIBRATION . 26 MOONRISE AND MOONSET . 27-31 SUN’S SELENOGRAPHIC COLONGITUDE . 32 LUNAR OCCULTATIONS . 33-39 GRAZING LUNAR OCCULTATIONS . 40-41 MARS . 42-43 ASTEROIDS . 44 ASTEROID EPHEMERIDES . 45-49 ASTEROID OCCULTATIONS (incl. TNO Hightlight:1998 WV31) . 50-53 ASTEROIDS: FAVOURABLE OBSERVING OPPORTUNITIES . 54-56 NEO CLOSE APPROACHES TO EARTH . 57 JUPITER . .. 58-62 SATELLITES OF JUPITER . .. 62-66 JUPITER ECLIPSES, OCCULTATIONS AND TRANSITS . 67-76 SATURN . 77-80 SATELLITES OF SATURN . 81-84 URANUS . 85 NEPTUNE . 86 TRANS–NEPTUNIAN & SCATTERED-DISK OBJECTS . 87 DWARF PLANETS . 88-91 COMETS . 92-96 METEOR DIARY . 97-99 VARIABLE STARS (RZ Cassiopeiae; Algol; RS Canum Venaticorum) . 100-101 MIRA STARS . 102 VARIABLE STAR OF THE YEAR (VV Cephei) . .. .. 103-105 EPHEMERIDES OF VISUAL BINARY STARS . 106-107 BRIGHT STARS . 108 ACTIVE GALAXIES . 109 TIME . 110-111 ASTRONOMICAL AND PHYSICAL CONSTANTS . 112-113 INTERNET RESOURCES . 114-115 GREEK ALPHABET . 115 ACKNOWLEDGEMENTS / ERRATA . 116 Front Cover: Mars - Apparent Diam. 18.4" taken from Barbados on 2016 June 05 by Damian Peach using a 356mm aper- ture Schmidt-Cassegrain telescope (North up) British Astronomical Association HANDBOOK FOR 2018 NINETY–SEVENTH YEAR OF PUBLICATION BURLINGTON HOUSE, PICCADILLY, LONDON, W1J 0DU Telephone 020 7734 4145 PREFACE Welcome to the 97th Handbook of the British Astronomical Association. The Handbook tries to highlight forthcoming astronomical events for the year but there are always events that can be missed, or are entirely unpredictable, like comets, asteroid close approaches, aurorae, etc. Make sure you watch the BAA’s website for the latest news. Also, make sure you are receiving the new email newsletters by keeping your email up to date with the BAA office. Once again we would also encourage everyone to join their local astronomical society to try equipment, talk to like-minded people, and to give and receive help. It can take a long time to choose the right equipment and learn how to use it, so make the most of your local society. The BAA’s Sections can help too. Contact the Section Directors, who will be pleased to help. Don't forget the special BAA Summer Meeting & Joint BAAVSS-AAVSO Meeting to be held at Warwick University : Saturday-Sunday July 7-8 (Organisers: Hazel Collett & Roger Pickard). (https://britastro.org/node/10727) You may also like to consider getting involved with the annual events organised as part of World Space Week (4-10 Oct.). This is an international celebration of all things SPACE and focuses on science and technology and its role in the past, present and future of mankind. World Space Week currently consists of space education and outreach events held by space agencies, aerospace companies, schools, planetaria, museums, and astronomy clubs around the world. (http://www.worldspaceweek.org/). Unfortunately we are restricted by the number of pages that we can include in the Handbook. This does mean that some things will have to be left out. However, the Computing Section does try to publish all additional data on the section website (http://britastro.org/computing). Members may also like to know that the Computing Section provides the data for the Royal Astronomical Society’s Diary. Finally, we must thank all the contributors to the Handbook. You will find them acknowledged on page 116. Contact details for many of these can be found at the back of every Journal. Alternatively, email the Director, Steve Harvey (address below) and messages can be forwarded to those concerned. Clear skies for 2018 ! Steve Harvey Director, Computing Section Email: [email protected] August 2017 2 Preface BAA Handbook 2018 HIGHLIGHTS FOR 2018 The following events during 2018 are worthy of note: Sun and Moon: There will be five eclipses (three of the Sun and two of the Moon). All three solar eclipses are partial and in polar regions so will be difficult to observe, The two lunar eclipse are both full. The eclipse of July 27 will be the most central umbral shadow since 2011. It will be visible (having already started) from moonrise in the UK. Planets, Dwarf Planets and Asteroids: Mercury is best seen in northern latitudes in the mornings in early January and mid to late August (for southern latitudes it is best seen in early to mid-January and mid-April to mid-May. In the evenings it is best seen around March and mid-June to early July.(July and late October to mid-November for southern latitudes). Venus is an evening object throughout the middle months of the year, reaching inferior conjunction on 26 Oct.., and then a morning object at the end of the year. A favourable Conjunction occurs with Mars and Jupiter (7 Jan.). Mars rises from the early morning hours at the beginning of the year and is visible throughout the year. Mars reaches perihelic opposition Jul. 27 (05:14) , with a diameter of 24.3" and magnitude -2.8 (From Greenwich transit is at 00:14 13°S) Meteors: Among the meteor showers, the most favourable are: the Lyrids (April), Perseids (August) and Draconids(October). Also favourable are: Capricornids, ι-Aquarids, Taurids, Leonids and Geminids. Comets: The comets 21P/Giacobini-Zinner and 46P/Wirtanen, which may reach naked eye brightness. 46P/Wirtanen is a special target for Pro-am observations in 2018. Also worth note (due to its tendency to outburst) is 29P/ Schwassmann-Wachmann. Refer to the BAA Comet Section for latest info : http://britastro.org/comet Space Probes and Artificial Satellites: NASA will launch its first mission to the sun during the summer of 2018 - the Parker Solar Probe. The Juno probe will deorbit into Jupiter during February. ESA's mission to Mercury, BepiColombo is sched- uled for launch in October. Predictions for the International Space Station and other bright satellites can be found for any geographic location at: http://www.heavens-above.com Highlights by date: Jan. 7 Mars 0.2° South of Jupiter 31 Total lunar eclipse visible from north-west America, the Pacific, Asia and Australia Feb. 15 Partial solar eclipse visible over Antarctica and finishing in South America. Mar. 20 The vernal equinox occurs in the northern hemisphere at 16:16 UT Apr. 22 Lyrid meteor shower May 9 Jupiter at opposition Jun. 28 Saturn at opposition.
Recommended publications
  • Asteroid Shape and Spin Statistics from Convex Models J

    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.
  • ESO's VLT Sphere and DAMIT

    ESO's VLT Sphere and DAMIT

    ESO’s VLT Sphere and DAMIT ESO’s VLT SPHERE (using adaptive optics) and Joseph Durech (DAMIT) have a program to observe asteroids and collect light curve data to develop rotating 3D models with respect to time. Up till now, due to the limitations of modelling software, only convex profiles were produced. The aim is to reconstruct reliable nonconvex models of about 40 asteroids. Below is a list of targets that will be observed by SPHERE, for which detailed nonconvex shapes will be constructed. Special request by Joseph Durech: “If some of these asteroids have in next let's say two years some favourable occultations, it would be nice to combine the occultation chords with AO and light curves to improve the models.” 2 Pallas, 7 Iris, 8 Flora, 10 Hygiea, 11 Parthenope, 13 Egeria, 15 Eunomia, 16 Psyche, 18 Melpomene, 19 Fortuna, 20 Massalia, 22 Kalliope, 24 Themis, 29 Amphitrite, 31 Euphrosyne, 40 Harmonia, 41 Daphne, 51 Nemausa, 52 Europa, 59 Elpis, 65 Cybele, 87 Sylvia, 88 Thisbe, 89 Julia, 96 Aegle, 105 Artemis, 128 Nemesis, 145 Adeona, 187 Lamberta, 211 Isolda, 324 Bamberga, 354 Eleonora, 451 Patientia, 476 Hedwig, 511 Davida, 532 Herculina, 596 Scheila, 704 Interamnia Occultation Event: Asteroid 10 Hygiea – Sun 26th Feb 16h37m UT The magnitude 11 asteroid 10 Hygiea is expected to occult the magnitude 12.5 star 2UCAC 21608371 on Sunday 26th Feb 16h37m UT (= Mon 3:37am). Magnitude drop of 0.24 will require video. DAMIT asteroid model of 10 Hygiea - Astronomy Institute of the Charles University: Josef Ďurech, Vojtěch Sidorin Hygiea is the fourth-largest asteroid (largest is Ceres ~ 945kms) in the Solar System by volume and mass, and it is located in the asteroid belt about 400 million kms away.
  • A Dwarf Planet Class Object in the 21:5 Resonance with Neptune

    A Dwarf Planet Class Object in the 21:5 Resonance with Neptune

    A dwarf planet class object in the 21:5 resonance with Neptune Holman, M. J., Payne, M. J., Fraser, W., Lacerda, P., Bannister, M. T., Lackner, M., Chen, Y. T., Lin, H. W., Smith, K. W., Kokotanekova, R., Young, D., Chambers, K., Chastel, S., Denneau, L., Fitzsimmons, A., Flewelling, H., Grav, T., Huber, M., Induni, N., ... Weryk, R. (2018). A dwarf planet class object in the 21:5 resonance with Neptune. Astrophysical Journal Letters, 855(1), [L6]. https://doi.org/10.3847/2041-8213/aaadb3 Published in: Astrophysical Journal Letters Document Version: Publisher's PDF, also known as Version of record Queen's University Belfast - Research Portal: Link to publication record in Queen's University Belfast Research Portal Publisher rights © 2018 American Astronomical Society. This work is made available online in accordance with the publisher’s policies. Please refer to any applicable terms of use of the publisher. General rights Copyright for the publications made accessible via the Queen's University Belfast Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The Research Portal is Queen's institutional repository that provides access to Queen's research output. Every effort has been made to ensure that content in the Research Portal does not infringe any person's rights, or applicable UK laws. If you discover content in the Research Portal that you believe breaches copyright or violates any law, please contact [email protected].
  • The Minor Planet Bulletin

    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.
  • STARDUST Newsletter of the Royal Astronomical Society of Canada Edmonton Centre

    STARDUST Newsletter of the Royal Astronomical Society of Canada Edmonton Centre

    STARDUST Newsletter of the Royal Astronomical Society of Canada Edmonton Centre September 2008 Volume 54 Issue 1 Partial eclipse, from high above the tundra near Cambridge Bay, 1 August 2008. Photo by Krista Stefan. Inside this Issue Contact Information................................................................................................................................................page 2 Upcoming Events, Meetings, Deadlines, Announcements.....................................................................................page 3 Public Education Report.........................................................................................................................................page 3 International Year of Astronomy Committee Report.............................................................................................page 3 Letter to RASC Edmonton Centre..........................................................................................................................page 4 President's Report....................................................................................................................................................page 4 Observers Report.....................................................................................................................................................page 4 Eclipse.....................................................................................................................................................................page 8 Beaver Hills Dark
  • Asteroid Family Ages. 2015. Icarus 257, 275-289

    Asteroid Family Ages. 2015. Icarus 257, 275-289

    Icarus 257 (2015) 275–289 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Asteroid family ages ⇑ Federica Spoto a,c, , Andrea Milani a, Zoran Knezˇevic´ b a Dipartimento di Matematica, Università di Pisa, Largo Pontecorvo 5, 56127 Pisa, Italy b Astronomical Observatory, Volgina 7, 11060 Belgrade 38, Serbia c SpaceDyS srl, Via Mario Giuntini 63, 56023 Navacchio di Cascina, Italy article info abstract Article history: A new family classification, based on a catalog of proper elements with 384,000 numbered asteroids Received 6 December 2014 and on new methods is available. For the 45 dynamical families with >250 members identified in this Revised 27 April 2015 classification, we present an attempt to obtain statistically significant ages: we succeeded in computing Accepted 30 April 2015 ages for 37 collisional families. Available online 14 May 2015 We used a rigorous method, including a least squares fit of the two sides of a V-shape plot in the proper semimajor axis, inverse diameter plane to determine the corresponding slopes, an advanced error model Keywords: for the uncertainties of asteroid diameters, an iterative outlier rejection scheme and quality control. The Asteroids best available Yarkovsky measurement was used to estimate a calibration of the Yarkovsky effect for each Asteroids, dynamics Impact processes family. The results are presented separately for the families originated in fragmentation or cratering events, for the young, compact families and for the truncated, one-sided families. For all the computed ages the corresponding uncertainties are provided, and the results are discussed and compared with the literature. The ages of several families have been estimated for the first time, in other cases the accu- racy has been improved.
  • Occultation Newsletter Volume 8, Number 4

    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.
  • Observations from Orbiting Platforms 219

    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.
  • GREAT Day 2007 Program

    GREAT Day 2007 Program

    Welcome to SUNY Geneseo’s First Annual G.R.E.A.T. Day! Geneseo Recognizing Excellence, Achievement & Talent Day is a college-wide symposium celebrating the creative and scholarly endeavors of our students. In addition to recognizing the achievements of our students, the purpose of G.R.E.A.T. Day is to help foster academic excellence, encourage professional development, and build connections within the community. The G.R.E.A.T. Day Planning Committee: Doug Anderson, School of the Arts Anne Baldwin, Sponsored Research Joan Ballard, Department of Psychology Anne Eisenberg, Department of Sociology Charlie Freeman, Department of Physics & Astronomy Tom Greenfield, Department of English Anthony Gu, School of Business Koomi Kim, School of Education Andrea Klein, Scheduling and Special Events The Planning Committee would like to thank: Stacie Anekstein, Ed Antkoviak, Brian Bennett, Cassie Brown, Michael Caputo, Sue Chichester, Betsy Colon, Laura Cook, Ann Crandall, Joe Dolce, Tammy Farrell, Carlo Filice, Richard Finkelstein, Karie Frisiras, Ginny Geer-Mentry, Becky Glass, Dave Gordon, Corey Ha, John Haley, Doug Harke, Gregg Hartvigsen, Tony Hoppa, Paul Jackson, Ellen Kintz, Nancy Johncox, Enrico Johnson, Ken Kallio, Jo Kirk, Sue Mallaber, Mary McCrank, Nancy Newcomb, Elizabeth Otero, Tracy Paradis, Jennifer Perry, Jewel Reardon, Ed Rivenburgh, Linda Shepard, Bonnie Swoger, Helen Thomas, Pam Thomas, and Taryn Thompson. Thank you to President Christopher Dahl and Provost Katherine Conway-Turner for their support of G.R.E.A.T. Day. Thank you to Lynn Weber for delivering our inaugural keynote address. The G.R.E.A.T. Day name was suggested by Elizabeth Otero, a senior Philosophy major.
  • Asteroid Family Identification 613

    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.
  • Asteroid Regolith Weathering: a Large-Scale Observational Investigation

    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.
  • On the Astrid Asteroid Family

    On the Astrid Asteroid Family

    MNRAS 461, 1605–1613 (2016) doi:10.1093/mnras/stw1445 Advance Access publication 2016 June 16 On the Astrid asteroid family Downloaded from https://academic.oup.com/mnras/article-abstract/461/2/1605/2608554 by Universidade Estadual Paulista J�lio de Mesquita Filho user on 29 May 2019 V. Carruba‹ UNESP, Univ. Estadual Paulista, Grupo de dinamicaˆ Orbital e Planetologia, 12516-410 Guaratingueta,´ SP, Brazil Accepted 2016 June 14. Received 2016 June 10; in original form 2016 May 2 ABSTRACT Among asteroid families, the Astrid family is peculiar because of its unusual inclination distribution. Objects at a 2.764 au are quite dispersed in this orbital element, giving the family a ‘crab-like’ appearance. Recent works showed that this feature is caused by the interaction of the family with the s − sC nodal secular resonance with Ceres, that spreads the inclination of asteroids near its separatrix. As a consequence, the currently observed distribution of the vW component of terminal ejection velocities obtained from inverting Gauss equation is quite leptokurtic, since this parameter mostly depends on the asteroids inclination. The peculiar orbital configuration of the Astrid family can be used to set constraints on key parameters describing the strength of the Yarkovsky force, such as the bulk and surface density and the thermal conductivity of surface material. By simulating various fictitious families with different values of these parameters, and by demanding that the current value of the kurtosis of the distribution in vW be reached over the estimated lifetime of the family, we obtained that the thermal conductivity of Astrid family members should be 0.001 W m−1 K−1, and that the surface and bulk density should be higher than 1000 kg m−3.