DOCSLIB.ORG

VNIR Spectral Properties of Five G-Class Asteroids: Implications for Mineralogy and Geologic Evolution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
VNIR Spectral Properties of Five G-Class Asteroids: Implications for Mineralogy and Geologic Evolution University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects January 2021 VNIR Spectral Properties Of Five G-Class Asteroids: Implications For Mineralogy And Geologic Evolution Justin Todd Germann Follow this and additional works at: https://commons.und.edu/theses Recommended Citation Germann, Justin Todd, "VNIR Spectral Properties Of Five G-Class Asteroids: Implications For Mineralogy And Geologic Evolution" (2021). Theses and Dissertations. 3927. https://commons.und.edu/theses/3927 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. VNIR SPECTRAL PROPERTIES OF FIVE G-CLASS ASTEROIDS: IMPLICATIONS FOR MINERALOGY AND GEOLOGIC EVOLUTION by Justin Todd Germann Bachelor of Science, University of North Dakota, 2017 A Thesis Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Master of Science Grand Forks, North Dakota May 2021 ii DocuSign Envelope ID: FACAE050-8099-49F3-B21B-B535F8B6B93E Justin Germann Name: Degree: Master of Science This document, submitted in partial fulfillment of the requirements for the degree from the University of North Dakota, has been read by the Faculty Advisory Committee under whom the work has been done and is hereby approved. ____________________________________ Dr. Sherry Fieber-Beyer ____________________________________ Dr. Michael Gaffey ____________________________________ Dr. Wayne Barkhouse ____________________________________ ____________________________________ ____________________________________ This document is being submitted by the appointed advisory committee as having met all the requirements of the School of Graduate Studies at the University of North Dakota and is hereby approved. ____________________________________ Chris Nelson Dean of the School of Graduate Studies 5/3/2021____________________________________ Date iii Title VNIR Spectral Properties of Five G-Class Asteroids: Implications for Mineralogy and Geologic Evolution Department Space Studies Degree Master of Science PERMISSION In presenting this thesis in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the library of this University shall make it freely available for inspection. I further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my thesis work or, in her absence, by the Chairperson of the department or the Dean of the School of Graduate Studies. It is understood that any copying or publication or other use of this thesis or part thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any scholarly use that may be made with any material in my thesis. Justin Todd Germann May 3rd, 2021 iv ACKNOWLEDGMENTS I would like to express my gratitude to my advisory committee - Dr. Sherry Fieber-Beyer, Dr. Mike Gaffey, and Dr. Wayne Barkhouse - for their support and guidance while working on the following research. Dr. Fieber-Beyer particularly deserves credit for suggesting research into the G-class asteroids, and Drs. Fieber-Beyer and Gaffey both deserve acclaim for their willingness to teach, mentor, and provide research opportunities for me throughout my graduate education. I would also like to thank all of my classmates and friends in Space Studies - particularly Elias Holte, Steven Russel, Will Green, Peter Henson, and Caleb Strom - for their friendship and support throughout our time together in Space Studies. Finally, I’d like to thank my longtime partner Kalea Hoff and my parents for putting up with my bewildering excitement and at times complaints over small, rocky bodies within our solar system. v TABLE OF CONTENTS Permission ...................................................................................................................................... iv Acknowledgments........................................................................................................................... v List of Figures ................................................................................................................................ ix List of Tables ................................................................................................................................ xii List of Equations .......................................................................................................................... xiii Abstract ........................................................................................................................................ xiv Chapter I: Introduction .................................................................................................................... 1 1.2: The Scientific SignifiCance of Asteroids and Meteorites .................................................... 2 1.3: Purpose ................................................................................................................................. 3 1.4: Problem Statement ............................................................................................................... 4 1.5: Thesis Structure .................................................................................................................... 5 Chapter II: Literature Review ......................................................................................................... 6 2.1: A Brief History of Asteroid Investigations .......................................................................... 6 2.2: Asteroid Belt Structure ......................................................................................................... 8 2.3: Observing Asteroids ........................................................................................................... 10 2.3.1: Photometry .................................................................................................................. 11 2.3.2: Spectroscopy ............................................................................................................... 12 2.4: Crystal Field Theory .......................................................................................................... 14 2.5: Space Weathering ............................................................................................................... 16 2.6: Asteroid Taxonomies ......................................................................................................... 18 vi 2.6.1: CMZ and Bowell taxonomies...................................................................................... 19 2.6.2: Tholen Asteroid Taxonomy......................................................................................... 20 2.6.3: Barucci Taxonomy ...................................................................................................... 22 2.6.4: Post ECAS Taxonomy................................................................................................. 22 2.7: G-Class Characteristics ...................................................................................................... 24 2.8: (1) Ceres - Evidence For Hydration ................................................................................... 29 2.9: Investigations into Possible Surface Minerals of C-complex Asteroids ............................ 30 2.10: Phyllosilicates and Hydrated Minerals ............................................................................. 32 2.11: Ammoniated Minerals ...................................................................................................... 38 2.12 Meteorite Classification Review ....................................................................................... 43 2.12.1 Chondrites................................................................................................................... 44 2.12.2 Achondrites................................................................................................................. 49 2.12.3 Meteorite Spectral Features ........................................................................................ 51 Chapter III: Methods ..................................................................................................................... 56 3.1: Targets ................................................................................................................................ 56 3.2: Observations and Data Collection ...................................................................................... 57 3.3: Asteroid Spectrum Reduction ............................................................................................ 58 3.3.1: Starpack Creation ........................................................................................................ 58 3.3.2: Atmospheric Corrections ............................................................................................. 60 3.3.3: Production of Nightly Average Spectrum ................................................................... 62 3.3.4: Spectral Normalization ...............................................................................................
Load more

Recommended publications
  • Hadrian and the Greek East
    HADRIAN AND THE GREEK EAST: IMPERIAL POLICY AND COMMUNICATION DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Demetrios Kritsotakis, B.A, M.A. * * * * * The Ohio State University 2008 Dissertation Committee: Approved by Professor Fritz Graf, Adviser Professor Tom Hawkins ____________________________ Professor Anthony Kaldellis Adviser Greek and Latin Graduate Program Copyright by Demetrios Kritsotakis 2008 ABSTRACT The Roman Emperor Hadrian pursued a policy of unification of the vast Empire. After his accession, he abandoned the expansionist policy of his predecessor Trajan and focused on securing the frontiers of the empire and on maintaining its stability. Of the utmost importance was the further integration and participation in his program of the peoples of the Greek East, especially of the Greek mainland and Asia Minor. Hadrian now invited them to become active members of the empire. By his lengthy travels and benefactions to the people of the region and by the creation of the Panhellenion, Hadrian attempted to create a second center of the Empire. Rome, in the West, was the first center; now a second one, in the East, would draw together the Greek people on both sides of the Aegean Sea. Thus he could accelerate the unification of the empire by focusing on its two most important elements, Romans and Greeks. Hadrian channeled his intentions in a number of ways, including the use of specific iconographical types on the coinage of his reign and religious language and themes in his interactions with the Greeks. In both cases it becomes evident that the Greeks not only understood his messages, but they also reacted in a positive way.
    [Show full text]
  • 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]
  • 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.
    [Show full text]
  • Heads Or Tails
    Heads or Tails Representation and Acceptance in Hadrian’s Imperial Coinage Name: Thomas van Erp Student number: S4501268 Course: Master’s Thesis Course code: (LET-GESM4300-2018-SCRSEM2-V) Supervisor: Mw. dr. E.E.J. Manders (Erika) 2 Table of Contents List of Figures ............................................................................................................................ 5 Figure 1: Proportions of Coin Types Hadrian ........................................................................ 5 Figure 2: Dynastic Representation in Comparison ................................................................ 5 Figure 3: Euergesia in Comparison ....................................................................................... 5 Figure 4: Virtues ..................................................................................................................... 5 Figure 5: Liberalitas in Comparison ...................................................................................... 5 Figure 6: Iustitias in Comparison ........................................................................................... 5 Figure 7: Military Representation in Comparison .................................................................. 5 Figure 8: Divine Association in Comparison ......................................................................... 5 Figure 9: Proportions of Coin Types Domitian ...................................................................... 5 Figure 10: Proportions of Coin Types Trajan .......................................................................
    [Show full text]
  • The Impact Crater at the Origin of the Julia Family Detected with VLT/SPHERE??,?? P
    A&A 618, A154 (2018) Astronomy https://doi.org/10.1051/0004-6361/201833477 & © ESO 2018 Astrophysics The impact crater at the origin of the Julia family detected with VLT/SPHERE??,?? P. Vernazza1, M. Brož2, A. Drouard1, J. Hanuš2, M. Viikinkoski3, M. Marsset4, L. Jorda1, R. Fetick1, B. Carry5, F. Marchis6, M. Birlan7, T. Fusco1, T. Santana-Ros8, E. Podlewska-Gaca8,9, E. Jehin10, M. Ferrais10, P. Bartczak8, G. Dudzinski´ 8, J. Berthier7, J. Castillo-Rogez11, F. Cipriani12, F. Colas7, C. Dumas13, J. Durechˇ 2, M. Kaasalainen3, A. Kryszczynska8, P. Lamy1, H. Le Coroller1, A. Marciniak8, T. Michalowski8, P. Michel5, M. Pajuelo7,14, P. Tanga5, F. Vachier7, A. Vigan1, B. Warner15, O. Witasse12, B. Yang16, E. Asphaug17, D. C. Richardson18, P. Ševecekˇ 2, M. Gillon10, and Z. Benkhaldoun19 1 Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France e-mail: [email protected] 2 Institute of Astronomy, Charles University, Prague, V Holešovickᡠch 2, 18000, Prague 8, Czech Republic 3 Department of Mathematics, Tampere University of Technology, PO Box 553, 33101 Tampere, Finland 4 Astrophysics Research Centre, Queen’s University Belfast, BT7 1NN, UK 5 Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, 06304 Nice Cedex 4, France 6 SETI Institute, Carl Sagan Center, 189 Bernado Avenue, Mountain View CA 94043, USA 7 IMCCE, Observatoire de Paris, 77 avenue Denfert-Rochereau, 75014 Paris Cedex, France 8 Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University,
    [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]
  • Dr. Emmanuel Ramírez Nieves
    Universidad de Puerto Rico Recinto de Río Piedras Departamento de Literatura Comparada Literatura Clásica Latina, LITE 3052. Segundo semestre, año académico 2018-2019. Profesor: Dr. Emmanuel Ramírez Nieves Oficina: Janer 129 Horas de oficina: lunes 2:30-3:30 p.m., jueves 2:30-3:50 p.m., o por acuerdo e-mail: [email protected] Salón: LPM 122 3 créditos, 3 horas Sitio web del curso: https://sites.google.com/s/1fS2hDv2GpvcfzZMmonitG4zlNk8eDWl1/p/1p_hGp5 0pCqmNd6Wl6d8u6pifZmL3awmR/edit Descripción general del curso: En esta parte del curso de dos semestres, estudiaremos la literatura clásica romana (desde el siglo III a. C. hasta los siglos IV y V d. C.) en sus contextos culturales e históricos. Leeremos ejemplos de varios géneros literarios clásicos: dramas de Séneca (tragedia) y Plauto (comedia), poemas de la lírica clásica latina de Catulo y Horacio, ensayos filosóficos de Cicerón, la épica La Eneida de Virgilio y las Metamorfosis de Ovidio, entre otros. Consideraremos éstos en relación con los textos filosóficos, cosmogónicos, científicos e históricos de la cultura clásica romana. Preguntaremos ¿qué significaba la literatura en la época clásica y cómo interpretan otros tiempos posteriores esta literatura? ¿Cuál era su importancia en la legitimación y formación de la cultura occidental durante los siglos? ¿Qué significa la literatura clásica dentro de los estudios de la literatura comparada en la UPR? Además de los estilos y el contenido de la literatura consideraremos también asuntos teóricos de género, la sex ualidad, el placer, las emociones, la formación de comunidades y la ética. Objetivos: Al finalizar el curso el y la estudiante: 1.
    [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]
  • 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]
  • Asteroids, Comets, Meteors 1991, Pp. 641-643 Lunar and Planetary Institute, Houston, 1992 W/Eg- 641
    Asteroids, Comets, Meteors 1991, pp. 641-643 Lunar and Planetary Institute, Houston, 1992 w/eg- 641 THE MASS OF (1) CERES FROM PERTURBATIONS ON (348) MAY Gareth V. Williams Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, U.S.A. ABSTRACT The most promising ground-based technique for determining the mass of s minor planet is the observation of the perturbations it induces in the motion of another minor planet. This method requires cv.reful observation of both minor planets over extended periods of time. The mass of (1) Ceres has been determined from the perturbations on (348) May, which made three close approaches to Ceres at intervals of 46 years between 1891 and 1984. The motion of May is clearly influenced by Ceres, and by Using different test masses for Ceres, a search has been made to determine the mass of Ceres that minimizes the residuals in the observations of May. Introduction The masses of the largest minor planets are rather poorly known. Traditionally, the masses of the major planets were obtained by observing their mutual perturbations or by observing their satellite systems. These methods are not easily applicable to minor planets: no minor planets are known to have satellites; the minor-planet perturbations on any of the major planets are negligible (from a ground-based viewpoint, except by tracking spacecraft); and the mutual minor-planet perturbations generally are small. However, the mutual-perturbation method, when applied to suitable objects, is the best ground-based method currently available for determimng minor-planet masses. The best circumstances for using this method occur when one of the minor planets is large compared to the other, when the two objects make close, periodic approaches to each other, and when both have long observational histories.
    [Show full text]
  • 23 Minor Planet Bulletin 41
    23 observation interval. The overall form of the lightcurve did not of the other observatories. To make the large number of data points change perceptibly with phase angle or viewing aspect. in the segments of the lightcurve included by Organ Mesa observations more legible, those data have been binned in sets of Further evidence against the double period near 72.6 hours is five points with a maximum of ten minutes between points. provided by Schober et al. (1993). They draw a composite bimodal lightcurve phased to 36.0 hours based on data from 6 consecutive References nights with about 60% phase coverage. Overlapping sessions on this lightcurve centered near 1989 Nov 30.3 and Dec 3.3 each Behrend, R. (2005). Observatoire de Geneve web site. show a small rise followed by a fall greater than 0.4 magnitudes in http://obswww.unige.ch/~behrend/page_cou.html about 6 hours. This sets a lower limit in their data for the amplitude. An amplitude as large as 0.4 magnitudes is possible Higgins, D.J., Menke, J., Pozzoli, V., Sheridan, E., and Dymock, only for a bimodal lightcurve. R. (2004). “Lightcurve and Period Determination for 582 Olympia.” Minor Planet Bull. 31, 12. Independently, Franco drew an H-G plot based only on sparse data from the U.S. Naval Observatory (USNO), i.e., not including any JPL (2013). http://ssd.jpl.nasa.gov/sbdb.cgi of the new photometry. These data contain no correction for rotational variation and in include the inherent scatter in the USNO Menke, J. (2011). Menke Scientific, Ltd.
    [Show full text]
  • The Warped Ways of Cosmic Light
    BIOLOGIE & MEDIZIN_Infektionsbiologie “Around that area there are indeed numerous small nebulous patches so close together that, upon seeing the region, one is positively startled by the strange appearance of this ‘nebula cluster’.” This was the sentiment expressed by Heidelberg-based astronomer Max Wolf in 1901 about the galaxy cluster in the constellation Coma Berenices. The cluster Abell 2218 presents a similar appearance to the viewer today on this image from the Hubble Space Telescope. The “strange appearance” – the many blue and orange arcs – owes, in this case, to the effect of a gravitational lens. PHYSICS & ASTRONOMY_Gravitational Lenses The Warped Ways of Cosmic Light Albert Einstein predicted them, modern giant telescopes detected them – and Klaus Dolag simulates them on a computer: gravitational lenses. The academic staff member at the Max Planck Institute for Astrophysics in Garching and at the University Observatory Munich uses this physical phenomenon to such ends as weighing galaxy clusters and probing that ominous substance known as dark matter. TEXT HELMUT HORNUNG he sky over Principe was a total eclipse of the Sun. The test was More recent analyses of Eddington’s cloudy and the mood in the simple: if a massive object bends space, findings show that the values measured camp on the coconut plan- then the Sun must also cause the pass- at that time did, indeed, correspond to tation had hit rock bottom. ing light from stars to deviate from its the prediction, but that they are appar- Having set out from Eng- straight course. In other words, the ently the result of an instrument error T land, the men had been traveling for points of light in the immediate vicin- of, as it so happens, the very same mag- weeks to reach the volcanic island in ity of the black Sun should be shifted nitude.
    [Show full text]