DOCSLIB.ORG

Leucus from Lightcurves and Occultations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Leucus from Lightcurves and Occultations The Planetary Science Journal, 1:73 (14pp), 2020 December https://doi.org/10.3847/PSJ/abb942 © 2020. The Author(s). Published by the American Astronomical Society. Convex Shape and Rotation Model of Lucy Target (11351) Leucus from Lightcurves and Occultations Stefano Mottola1 , Stephan Hellmich1, Marc W. Buie2 , Amanda M. Zangari2,4, Simone Marchi2, Michael E. Brown3, and Harold F. Levison2 1 Institute of Planetary Research, DLR Rutherfordstr. 2, D-12489 Berlin, Germany; stefano.mottola@dlr.de 2 Southwest Research Institute 1050 Walnut Street, Boulder, CO 80302, USA 3 California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA Received 2020 July 6; revised 2020 September 1; accepted 2020 September 15; published 2020 December 8 Abstract We report new photometric lightcurve observations of the Lucy Mission target (11351) Leucus acquired during the 2017, 2018, and 2019 apparitions. We use these data in combination with stellar occultations captured during five epochs to determine the sidereal rotation period, the spin axis orientation, a convex shape model, the absolute scale of the object, its geometric albedo, and a model of the photometric properties of the target. We find that Leucus is a prograde rotator with a spin axis located within a sky-projected radius of 3°(1σ) from J2000 Ecliptic coordinates (λ=208°, β=+77°) or J2000 Equatorial Coordinates (R.A.=248°,decl.=+58°). The sidereal period is refined to Psid=445.683±0.007 h. The convex shape model is irregular, with maximum dimensions of 60.8, 39.1, and 27.8 km. The convex model accounts for global features of the occultation silhouettes, although minor deviations suggest that local and global concavities are present. We determine a geometric albedo of pV=0.043±0.002. The derived phase curve supports a D-type classification for Leucus. Unified Astronomy Thesaurus concepts: Light curves (918); Stellar occultation (2135); Jupiter trojans (874); CCD photometry (208) Supporting material: machine-readable table 1. Introduction encounters and to complement the space-based measurements with data that are most efficiently acquired from the ground. Jupiter Trojans are a class of small objects trapped in the Jupiter This paper presents new lightcurve photometry of the Lucy L4 and L5 Lagrangian points. Their origin is still disputed, with target Leucus, which is used, together with the results of stellar the most likely scenarios falling into the categories (1) coeval occultation campaigns presented in a companion paper (Buie trapping of local planetesimals in the 1:1 mean motion resonance et al. 2020), to determine its convex shape, spin axis orientation, with accreting Jupiter as a consequence of drag or collisions albedo, size, sphere-integrated phase curve, and V–R color index. (Yoder 1979; Shoemaker et al. 1989) or (2) post-Jupiter-formation capture of scattered trans-Neptunian planetesimals following an episode of orbital chaos (Morbidelli et al. 2005) during the orbital 2. Leucus migration of the giant planets or as a consequence of the Jumping ( ) fi ( ) 11351 Leucus belongs to the Jupiter L4 Trojan swarm. Jupiter scenario as de ned in Nesvorný et al. 2013 . In either Radiometric measurements by the IRAS satellite reported a size case, Trojans are thought to be primitive objects that experienced and a geometric albedo of 42.2±4.0 km and 0.063±0.014, little thermal evolution and contain a considerable amount of respectively (Tedesco et al. 2004). Grav et al. (2012) reported a volatiles, which makes them close relatives to cometary nuclei. size and an albedo of 34.155±0.646 km and 0.079±0.013, With a launch planned for 2021 October, Lucy is the thirteenth fi fi respectively, based on Wide- eld Infrared Survey Explorer NASA mission of the Discovery Program and will be the rst one (WISE) radiometry. Levison & Lucy Science Team (2016) to explore the Jupiter Trojan System. Its trajectory is designed to tentatively classified Leucus as belonging to the D taxonomic flybyfive Trojans—one of which, (617) Patroclus is an equal-size ( ) — type based on its visible spectral slope Roig et al. 2008 .No binary system distributed over the two Lagrangian clouds. The collisional family membership has been proposed as of today. encounter with Leucus is currently planned for 2028 June 18. A French et al. (2013) first realized from lightcurve data that coordinated effort has been initiated to support the mission with a Leucus is a very slow rotator, although they identified an systematic program of ground-based observations of the mission incorrect period of 515h. Buie et al. (2018), using photometric targets aiming at characterizing their dynamical, physical, observations acquired during the 2016 apparition, combined rotational, and photometric properties. The goal is to inform the ( ) fi fi with observations by French 2013 , determined a rm rotation mission design in order to maximize the scienti creturnofthe period of 445.732±0.021h. They also estimated a geometric 4 albedo of 0.047 based on the WISE diameter and on an average Amanda Zangari is currently an MIT Lincoln Laboratory employee. No color index for D-type asteroids. laboratory funding or resources were used to produce the results/findings reported in this publication. 3. Observations and Data Reduction Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further The new Leucus photometric observations reported in this distribution of this work must maintain attribution to the author(s) and the title paper were performed during its 2017, 2018, and 2019 apparitions of the work, journal citation and DOI. by using 1.0 m telescopes from the Las Cumbres Observatory 1 The Planetary Science Journal, 1:73 (14pp), 2020 December Mottola et al. Table 1 Observational Circumstances λ ( ) β Date λβ α r Δ PAB Band Observatory Observers (UT)(° J2000)(°)(au)(au)(° J2000) 2017 May 1.1 287.4 +5.7 9.683 5.507 1 5.032 0 282.5 +5.5 RC 493 SH, SMo 2017 May 2.1 287.4 +5.8 9.616 5.506 7 5.017 5 282.6 +5.5 RC 493 SH, SMo 2017 May 20.1 287.0 +6.3 7.887 5.500 5 4.774 5 283.0 +5.9 RC 493 SH, SMo 2017 May 28.1 286.5 +6.6 6.841 5.497 7 4.685 2 283.1 +6.1 RC 493 SMo, SH 2017 May 30.1 286.3 +6.6 6.550 5.497 0 4.664 6 283.1 +6.1 RC 493 SMo, SH 2017 May 31.0 286.3 +6.6 6.408 5.496 6 4.655 1 283.1 +6.1 RC 493 SMo, SH 2017 Jul 16.4 281.0 +7.6 2.738 5.479 8 4.491 4 282.2 +6.9 r′ Q64 MWB, AZ 2017 Jul 17.0 280.9 +7.6 2.833 5.479 5 4.493 2 282.1 +6.9 r′ W86 MWB, AZ 2017 Jul 17.3 280.9 +7.6 2.882 5.479 4 4.494 2 282.1 +6.9 r′ W85 MWB, AZ 2017 Jul 17.6 280.8 +7.6 2.933 5.479 3 4.495 2 282.1 +6.9 r′ Q63 MWB, AZ 2017 Jul 17.9 280.8 +7.6 2.980 5.479 2 4.496 2 282.1 +6.9 r′ K93 MWB, AZ 2017 Jul 18.2 280.8 +7.6 3.031 5.479 1 4.497 3 282.1 +6.9 r′ W86 MWB, AZ 2018 Jun 11.1 318.3 +11.1 9.382 5.339 4 4.745 1 313.5 +10.5 RC 493 SH, SMo 2018 Jul 9.1 316.6 +12.1 5.829 5.326 3 4.437 9 313.8 +11.1 V 493 SH, SMo 2018 Jul 15.0 316.0 +12.2 4.895 5.323 6 4.394 7 313.8 +11.2 V 493 SH, SMo 2018 Sep 4.9 309.8 +12.5 6.171 5.299 0 4.436 2 312.8 +11.5 V 493 SH, SMo 2018 Aug 6.9 313.2 +12.7 2.406 5.312 7 4.318 6 313.3 +11.5 RC 493 SH, SMo 2018 Aug 8.0 313.1 +12.7 2.432 5.312 3 4.318 7 313.3 +11.5 RC 493 SH, SMo 2018 Aug 9.0 312.9 +12.7 2.475 5.311 8 4.319 2 313.3 +11.5 RC 493 SH, SMo 2019 Nov 9.1 342.2 +12.6 10.103 5.101 6 4.597 6 347.3 +12.0 VR G80 MWB 2019 Nov 10.1 342.2 +12.6 10.181 5.101 2 4.611 2 347.4 +12.0 VR G80 MWB 2019 Nov 11.1 342.2 +12.5 10.257 5.100 8 4.624 9 347.4 +12.0 VR G80 MWB 2019 Nov 12.1 342.2 +12.5 10.329 5.100 4 4.638 7 347.5 +11.9 VR G80 MWB 2019 Nov 24.1 342.6 +12.0 10.962 5.095 5 4.812 3 348.2 +11.7 VR G80 MWB Note. This table is an excerpt. The observational circumstances for all of the observation nights are reported in the online material. λ and β are the topocentric ecliptic longitude and latitude of the target, respectively. α is the solar phase angle, r is the heliocentric distance, and Δ is the topocentric range of Leucus. λ and β (PAB) are the topocentric ecliptic longitude and latitude of the phase angle bisector, as defined in Harris et al.
Load more

Recommended publications
  • Astrocladistics of the Jovian Trojan Swarms
    MNRAS 000,1–26 (2020) Preprint 23 March 2021 Compiled using MNRAS LATEX style file v3.0 Astrocladistics of the Jovian Trojan Swarms Timothy R. Holt,1,2¢ Jonathan Horner,1 David Nesvorný,2 Rachel King,1 Marcel Popescu,3 Brad D. Carter,1 and Christopher C. E. Tylor,1 1Centre for Astrophysics, University of Southern Queensland, Toowoomba, QLD, Australia 2Department of Space Studies, Southwest Research Institute, Boulder, CO. USA. 3Astronomical Institute of the Romanian Academy, Bucharest, Romania. Accepted XXX. Received YYY; in original form ZZZ ABSTRACT The Jovian Trojans are two swarms of small objects that share Jupiter’s orbit, clustered around the leading and trailing Lagrange points, L4 and L5. In this work, we investigate the Jovian Trojan population using the technique of astrocladistics, an adaptation of the ‘tree of life’ approach used in biology. We combine colour data from WISE, SDSS, Gaia DR2 and MOVIS surveys with knowledge of the physical and orbital characteristics of the Trojans, to generate a classification tree composed of clans with distinctive characteristics. We identify 48 clans, indicating groups of objects that possibly share a common origin. Amongst these are several that contain members of the known collisional families, though our work identifies subtleties in that classification that bear future investigation. Our clans are often broken into subclans, and most can be grouped into 10 superclans, reflecting the hierarchical nature of the population. Outcomes from this project include the identification of several high priority objects for additional observations and as well as providing context for the objects to be visited by the forthcoming Lucy mission.
    [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]
  • Trajectory Design of the Lucy Mission to Explore the Diversity of the Jupiter Trojans
    70th International Astronautical Congress, Washington, DC. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. IAC–2019–C1.2.11 Trajectory Design of the Lucy Mission to Explore the Diversity of the Jupiter Trojans Jacob A. Englander Aerospace Engineer, Navigation and Mission Design Branch, NASA Goddard Space Flight Center Kevin Berry Lucy Flight Dynamics Lead, Navigation and Mission Design Branch, NASA Goddard Space Flight Center Brian Sutter Totally Awesome Trajectory Genius, Lockheed Martin Space Systems, Littleton, CO Dale Stanbridge Lucy Navigation Team Chief, KinetX Aerospace, Simi Valley, CA Donald H. Ellison Aerospace Engineer, Navigation and Mission Design Branch, NASA Goddard Space Flight Center Ken Williams Flight Director, Space Navigation and Flight Dynamics Practice, KinetX Aerospace, Simi Valley, California James McAdams Aerospace Engineer, Space Navigation and Flight Dynamics Practice, KinetX Aerospace, Simi Valley, California Jeremy M. Knittel Aerospace Engineer, Space Navigation and Flight Dynamics Practice, KinetX Aerospace, Simi Valley, California Chelsea Welch Fantastically Awesome Deputy Trajectory Genius, Lockheed Martin Space Systems, Littleton, CO Hal Levison Principle Investigator, Lucy mission, Southwest Research Institute, Boulder, CO Lucy, NASA’s next Discovery-class mission, will explore the diversity of the Jupiter Trojan asteroids. The Jupiter Trojans are thought to be remnants of the early solar system that were scattered inward when the gas giants migrated to their current positions as described in the Nice model. There are two stable subpopulations, or “swarms,” captured at the Sun-Jupiter L4 and L5 regions. These objects are the most accessible samples of what the outer solar system may have originally looked like.
    [Show full text]
  • Kuiper Belt and Comets: an Observational Perspective
    Kuiper Belt and Comets: An Observational Perspective David Jewitt1 1. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 jewitt@hawaii.edu Note to the Reader These notes outline a series of lectures given at the Saas Fee Winter School held in Murren, Switzerland, in March 2005. As I see it, the main aim of the Winter School is to communicate (especially) with young people in order to inflame their interests in science and to encourage them to see ways in which they can contribute and maybe do a better job than we have done so far. With this in mind, I have written up my lectures in a less than formal but hopefully informative and entertaining style, and I have taken a few detours to discuss subjects that I think are important but which are usually glossed-over in the scientific literature. 1 Preamble Almost exactly 400 years ago, planetary astronomy kick-started the era of modern science, with a series of remarkable discoveries by Galileo concerning the surfaces of the Moon and Sun, the phases of Venus, and the existence and motions of Jupiter’s large satellites. By the early 20th century, the fo- cus of astronomical attention had turned to objects at larger distances, and to questions of galactic structure and cosmological interest. At the start of the 21st century, the tide has turned again. The study of the Solar system, particularly of its newly discovered outer parts, is one of the hottest topics in modern astrophysics with great potential for revealing fundamental clues about the origin of planets and even the emergence of life.
    [Show full text]
  • Highlights of Stellar Occultations by Asteroids with Moons in 2021
    Highlights of Stellar Occultations by Asteroids with Moons in 2021 Occultation by (87) Sylvia, Romulus & Remus, 2019 Oct 29 Romulus Remus Web Video Conference ESOP XXXIX, August 2020 Oliver Klös - IOTA/ES Highlights of Stellar Occultations by Asteroids with Moons in 2021 Asteroid Moon(s) Area (22) Kalliope Linus Europe & N. America (31) Euphrosyne S2019-31-1 Australasia (45) Eugenia Petit-Prince & Petite-Princesse Europe (87) Sylvia Romulus & Remus Europe (283) Emma S2003 -283-1 Europe (617) Patroclus Menoetius Europe Web Video Conference ESOP XXXIX, August 2020 Oliver Klös - IOTA/ES Highlights of Stellar Occultations by Asteroids with Moons in 2021 Asteroid Moon(s) Area (22) Kalliope Linus Europe & N. America (31) Euphrosyne S2019-31-1 Australasia (2020/2021) (45) Eugenia Petit-Prince & Petite-Princesse Europe (87) Sylvia Romulus & Remus Europe (283) Emma S2003 -283-1 Europe (617) Patroclus Menoetius Europe Calculations were made with Occult V4 and JPL Horizons data Filters: Orbital elements for moons available from Miriade (IMCCE) Target star listed in Gaia DR2 14 Duration > 0.2 s Mag drop > 0.15 mag Web Video Conference ESOP XXXIX, August 2020 Oliver Klös - IOTA/ES Highlights of Stellar Occultations by Asteroids with Moons in 2021 Agenda of Predictions: I. Occultations for Europe (chronological order) II. Occultations by (22) Kalliope & Linus (N. America) III. Occultations by (31) Euphrosyne & S2019-31-1 (Australasia in 2020/2021) Web Video Conference ESOP XXXIX, August 2020 Oliver Klös - IOTA/ES Highlights of Stellar Occultations by
    [Show full text]
  • Menoetius Trojan Binary
    The Upcoming Mutual Event Season for the Patroclus – Menoetius Trojan Binary W.M. Grundya, K.S. Nollb, M.W. Buiec, and H.F. Levisonc a. Lowell Observatory, Flagstaff AZ 86001. b. NASA Goddard Space Flight Center, Greenbelt MD 20771. c. Southwest Research Institute, Boulder CO 80302. ── Published in 2018 in Icarus 305, 198-202 (DOI 10.1016/j.icarus.2018.01.009) ── Abstract We present new Hubble Space Telescope and ground-based Keck observations and new Keplerian orbit solutions for the mutual orbit of binary Jupiter Trojan asteroid (617) Patroclus and Menoetius, targets of NASA’s Lucy mission. We predict event times for the upcoming mutual event season, which is anticipated to run from late 2017 through mid 2019. Introduction As the first known binary Jupiter Trojan, Patroclus and Menoetius provided the first opportunity to directly measure the mass and thus bulk density of objects from this population. Marchis et al. (2005; 2006) determined their mutual orbit to have a period of 4.283 ± 0.004 days and a semimajor axis of 680 ± 20 km, leading to a system mass of (1.36 ± 0.11) x 1018 kg. When the plane of their mutual orbit is aligned with the direction to the Sun or to an observer, Patroclus and Menoetius take turns eclipsing or occulting one another. Such an alignment occurs during mutual event seasons, twice every ~12 year orbit around the Sun. Spitzer Space Telescope thermal observations of Patroclus – Menoetius mutual events enabled Mueller et al. (2010) to determine that the surface thermal inertia is relatively low, consistent with mature regolith.
    [Show full text]
  • Six Hot Topics in Planetary Astronomy
    Six Hot Topics in Planetary Astronomy David Jewitt Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA jewitt@hawaii.edu Abstract Six hot topics in modern planetary astronomy are described: 1) lightcurves and densities of small bodies 2) colors of Kuiper belt objects and the distri- bution of the ultrared matter 3) spectroscopy and the crystallinity of ice in the outer Solar system 4) irregular satellites of the giant planets 5) the Main Belt Comets and 6) comets and meteor stream parents. 1 Introduction The direction given to the authors of this book1 is to show some of the exciting recent developments in the study of the Solar system. Of course, \exciting" is a subjective term, and one which gives this author a lot of latitude. The most exciting science subjects for me are the ones I am working on, so I have written this chapter as a series of vignettes describing six topics from my own on-going research and from the research of my students and colleagues [principally Henry Hsieh (main belt comets), Bin Yang (spectra), Jane Luu (colors and spectra), Scott Sheppard (irregular satellites and lightcurves), Pedro Lacerda (lightcurves), Nuno Peixinho (colors) and Toshi Kasuga (meteors)]. What follows is not so much a review as a window onto these six, particularly active parts of modern planetary astronomy. The reader who wants the raw science or access to the full literature on a given subject has only to go to the journals or to astro-ph: the internet makes it easy. My objective here is to focus attention mainly on newer, perhaps less-known work, the big-picture significance of arXiv:0811.2265v1 [astro-ph] 14 Nov 2008 1 Article completed in January 2008 and to be published in \Small Bodies in Plan- etary Systems" (Mann, Nakamura and Mukai, editors), Lecture Notes in Physics, Volume 758, Springer Academic Publishers, 2008.
    [Show full text]
  • Ice & Stone 2020
    Ice & Stone 2020 WEEK 15: APRIL 5-11, 2020 Presented by The Earthrise Institute # 15 Authored by Alan Hale This week in history APRIL 5 6 7 8 9 10 11 APRIL 5, 1861: An amateur astronomer in New York, A.E. Thatcher, discovers a 9th-magnitude comet. Comet Thatcher was found to have an approximate orbital period of 415 years and is the parent comet of the Lyrid meteor shower, which peaks around April 22 each year. The Lyrids usually put on a modest display of less than 20 meteors per hour, but on occasion have produced much stronger displays, most recently in 1982. APRIL 5 6 7 8 9 10 11 APRIL 8, 1957: Comet Arend-Roland 1956h passes through perihelion at a heliocentric distance of 0.316 AU. This was one of the brighter comets of the mid-20th Century and is a future “Comet of the Week.” APRIL 8, 2024: The path of a total solar eclipse will cross north-central Mexico and the south-central and northeastern U.S. This may be my last, best chance to see an eclipse comet; I discuss these in a future “Special Topics” presentation. APRIL 5 6 7 8 9 10 11 APRIL 9, 1994: Radar bounce experiments conducted by the joint NASA/U.S. Defense Department Clementine spacecraft suggest the presence of water ice in permanently shadowed craters near the moon’s South Pole. This would be confirmed by NASA’sLunar Prospector mission in 1998. These experiments are discussed as part of a future “Special Topics” presentation. *There are no calendar entries for April 6 and 7.
    [Show full text]
  • Department: “ASTEROIDS and COMETS” X. Report 2006/2007
    Deutsches Zentrum für Luft- und Raumfahrt e.V. German Aerospace Center Institut für Planetenforschung Institute of Planetary Research Department: “ASTEROIDS and COMETS” X. Re port 2006/2007 Comets Asteroids Technology Space Missions MODELS http://solarsystem.dlr.de From left to right Dr. Ekkehard Kührt ekkehard.kuehrt@dlr.de Section leader Dr. Alan W. Harris alan.harris@dlr.de Deputy section leader Dr. Gerhard Hahn gerhard.hahn@dlr.de Scientific staff member Nikolaos Gortsas nikolaos.gortsas@dlr.de PhD student Dr. Stefano Mottola stefano.mottola@dlr.de Scientific staff member Dr. Detlef de Niem detlef.deniem@dlr.de Scientific staff member Dr. Jörg Knollenberg joerg.knollenberg@dlr.de Scientific staff member Not appearing in the photo: Prof. Uwe Motschmann uwe.motschmann@dlr.de Guest scientist Dr. Carmen Tornow carmen.tornow@dlr.de Scientific staff member Dr. Michael Solbrig michael.solbrig@dlr.de Engineer 2 1 Introduction (Kührt).................................................................................................. 4 2 Asteroid Science ....................................................................................................... 4 2.1 Investigations of the physical properties of asteroids with the Spitzer Space Telescope (Harris, Müller)....................................................................................... 4 2.2 Asteroid thermal modelling (Mueller, Harris) .......................................................... 5 2.3 Spectroscopic observations of 12 NEAs with UKIRT (Harris) ...................................
    [Show full text]
  • Society Amateur Astronomy News and Views in Southwestern Virginia
    Roanoke Valley Astronomical Society Amateur Astronomy News and Views In Southwestern Virginia Volume 31—Number 2 February 2014 RVAS January Meeting Notes Coming to you live . by Rick Rader, RVAS Secretary From Seattle, Washington, it's--wait, wait, don't tell me! Sorry to steal a line from the Sunday morning NPR pro- gram, but our January Club gathering was yet another example of why you may wish to brave the elements to meet with your fellow all-things-astronomical enthusi- asts. In a first for a monthly meeting, RVAS President Frank Baratta and Mark Hodges (all things mystical and elec- trical Science Museum master) orchestrated an intri- guing hour with Tom Field, live via webcast from his lo- cation in Seattle. A contributing editor at Sky & Tele- scope magazine and author of RSpec software, Tom re- Frank Baratta Tom Field galed the twenty eight hardy souls present with an ad- RVAS President connects with for the evening’s live webcast talk. venture delving into the surprisingly easy world of hard Photo by John Goss science: spectroscopic investigation of light emitting objects of all types in our universe. had been born. The bombardment of energy reaching Earth can be ana- Fast forward. Spectroscopy has taught us that every lyzed to reveal the constituent elements of a celestial element of the Periodic Table when heated emits or ab- object. The process is not brand new, having been first sorbs light of specific wavelengths, which appear as defined by Newton with his prism experiments. Joseph lines in their otherwise continuous, multi-colored spec- von Fraunhofer, a wonderfully skilled glass maker, ob- tra.
    [Show full text]
  • Arxiv:2104.04575V1 [Astro-Ph.IM] 9 Apr 2021 Mal Infrared Spectrometer
    Draft version April 13, 2021 Typeset using LATEX default style in AASTeX63 Lucy Mission to the Trojan Asteroids: Instrumentation and Encounter Concept of Operations Catherine B. Olkin,1 Harold F. Levison,1 Michael Vincent,1 Keith S. Noll,2 John Andrews,1 Sheila Gray,3 Phil Good,3 Simone Marchi,1 Phil Christensen,4 Dennis Reuter,2 Harold Weaver,5 Martin Patzold¨ ,6 James F. Bell III,4 Victoria E. Hamilton,1 Neil Dello Russo,5 Amy Simon,2 Matt Beasley,1 Will Grundy,7 Carly Howett,1 John Spencer,1 Michael Ravine,8 and Michael Caplinger8 1Southwest Research Institute 1050 Walnut Street, Suite 300 Boulder, CO 80302, USA 2NASA Goddard Spaceflight Center 8800 Greenbelt Rd. Greenbelt, MD 20771 3Lockheed Martin Corp. 12257 South Wadsworth Blvd. Littleton, CO 80125 4Arizona State University Tempe, AZ 85281 5Johns Hopkins University Applied Physics Laboratory 7651 Montpelier Rd. Laurel, MD 20723 6RIU-PF at Cologne University Cologne, Germany 7Lowell Observatory 1400 Mars Hill Rd. Flagstaff, AZ 86001 8Malin Space Science Systems 5880 Pacific Center Blvd. San Diego, CA 92121 (Received December 18, 2021; Accepted February 24, 2021) Submitted to PSJ ABSTRACT The Lucy Mission accomplishes its science during a series of five flyby encounters with seven Trojan asteroid targets. This mission architecture drives a concept of operations design that maximizes science return, provides redundancy in observations where possible, features autonomous fault protection and utilizes onboard target tracking near closest approach. These design considerations reduce risk during the relatively short time-critical periods when science data is collected. The payload suite consists of a color camera and infrared imaging spectrometer, a high-resolution panchromatic imager, and a ther- arXiv:2104.04575v1 [astro-ph.IM] 9 Apr 2021 mal infrared spectrometer.
    [Show full text]
  • Ultraviolet Spectroscopy of Jupiter Trojans Patroclus and Leucus Using the Hubble Space Telescope
    EPSC Abstracts Vol. 13, EPSC-DPS2019-698-1, 2019 EPSC-DPS Joint Meeting 2019 c Author(s) 2019. CC Attribution 4.0 license. Ultraviolet Spectroscopy of Jupiter Trojans Patroclus and Leucus Using the Hubble Space Telescope Oriel A. Humes (1), Cristina A. Thomas (1), Joshua P. Emery (1,2) and Keith S. Noll (3) (1) Northern Arizona University, Arizona, USA, (2) University of Tennessee at Knoxville, Tennessee, USA (3) NASA Goddard Space Flight Center, Maryland, USA Abstract towards longer wavelengths, resulting in reddish spec- tral slopes. In visible-near infrared spectral slope, the Interest in the Jupiter Trojans, a population of small Trojan population is bimodal, with two spectral groups bodies that orbit in Jupiter’s L4 and L5 Lagrange called the “red” and “less-red” populations [7]. At points, has increased in recent years, particularly with longer wavelengths, in the thermal infrared, an emis- the selection of the NASA Discovery class mission sion feature at 10 microns has been observed [1]. This Lucy, which will visit five Jupiter Trojans in the late feature is interpreted to be due to fine grained silicates 2020s to early 2030s. Despite this, the spectra of the in a fairy castle structure or suspended in a transpar- Trojan population remains enigmatic due to a relative ent matrix. The ultraviolet region of the spectrum is paucity of features in the visible and infrared regions. also useful for investigating space weathering on small We present the ultraviolet spectra (>200 nm) from the bodies. Recent ultraviolet spectra of six Jupiter Tro- Hubble Space Telescope of the two Trojan asteroids jans have found that the trend in spectral slopes in the (617) Patroclus and (11351) Leucus.
    [Show full text]