DOCSLIB.ORG

67-6936 LEE, Thomas Alan, 1939- INTERSTELLAR EXTINCTION IN

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
67-6936 LEE, Thomas Alan, 1939- INTERSTELLAR EXTINCTION IN INTERSTELLAR EXTINCTION IN THE ORION ASSOCIATION Item Type text; Dissertation-Reproduction (electronic) Authors Lee, Thomas Alan, 1939- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 04/10/2021 12:54:51 Link to Item http://hdl.handle.net/10150/284825 This dissertation has been microfilmed exactly as received 67-6936 LEE, Thomas Alan, 1939- INTERSTELLAR EXTINCTION IN THE ORION ASSOCIATION. University of Arizona, Ph.D., 1967 Astronomy University Microfilms, Inc., Ann Arbor, Michigan INTERSTELLAR EXTINCTION IN THE ORION ASSOCIATION by Thomas Alan Lee A Dissertation Submitted to the Faculty of the DEPARTMENT OF ASTRONOMY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 19 6 7 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE I hereby recommend that this dissertation prepared under my direction by Thomas A. Lee entitled Interstellar Extinction in the Orion Association be accepted as fulfilling the dissertation requirement of the degree of Doctor of Philosophy ? Cj /ty fid? Dissertation Director Date After inspection of-the dissertation, the following members of the Final Examination Committee concur in its approval and recommend its acceptance:* r. 4)oJlh* &ZrL£-£ S-& a)cKT~ hfa >~) o Aj ns h ( *This approval and acceptance is contingent on the candidate's adequate performance and defense of this dissertation at the final oral examination. The inclusion of this sheet bound into the library copy of the dissertation is evidence of satisfactory performance at the final examination. STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of the requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allow­ able without special permission, provided that accurate acknowledgment of the source is made. Requests for permis­ sion for extended quotation from or reproduction of this manuscript in v/hole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. cif Jfl / SIGNED: ACKNOWLEDGMENTS It is a pleasure to thank the many people who aided me in the various phases of this work. Assistance from the following individuals is hereby gratefully acknowledged: Mrs. Kathryn Sheffer for managing the data process­ ing and being helpful in many, many ways; Mr. Richard Mitchell for helpful discussions con­ cerning photometric systems and data analysis; Mr. Braulio Iriarte and Dr. Manuel Mendez for courtesies extended to me during a pleasant and rewarding visit to Mexico; Dr. Guillermo Haro for allowing me to take several of his infrared plates to Tucson for copying and detailed study; Dr. Bart Bok for his interest, encouragement., and helpful suggestions; Drs. Manuel Mendez and Robert Williams for interest ing and valuable discussions; Mr. Ed Howell for his help with photographic problems; Mrs. Helena Davis and Miss Judy Ackerman for assist ing in the preparation of the final draft; iii iv Mrs. Dorothy Conniff for typing the final draft; and all the personnel of the Lunar and Planetary Laboratory v/ho helped make this project so enjoyable. I am greatly indebted to Dr. Harold L. Johnson, v/ho directed this research and made the photometric equipment of the Lunar and Planetary Laboratory available for this investigation. He has given freely of his time and energy in providing continued guidance and encouragement. The consideration and interest he has shown are deeply appreci­ ated . This project was supported by the National Science Foundation under grants GP 3^-1^ and GP 5129. TABLE OF CONTENTS Page LIST OP FIGURES "J"- vii LIST OF TABLES ix ABSTRACT x I. Introduction 1 A. Observational Work 1 B. Theoretical Results 10 C. The Orion Region 19 1. General 19 2. Extinction in the Orion Nebula .... 19 II. Observational Data 25 A. Selection of Stars 25 B. Equipment and Techniques . 25 C. The Data 30 III. Intrinsic Colors of Early-Type Stars 43 A. Unreddened Early-Type Stars 43 B. The U-B and B-V Color Indices ....... 43 C. The Infrared Color Indices 46 D. The V-L Index 51 IV. Extinction Curve Calculations 54 A. Method 54 1. Color Excesses 54 v vi 2. Normalization and Scaling 54 B. The Ratio 55 V. Regional Mean Extinction Laws 59 A. Probable Errors and Weights 59 B. Properties of the Regional Laws 69 VI. Related Phenomena Modifying the Extinction Interpretation 80 A. The 'Belt' Region 80 B. The 'Sword' Region 83 1. Anomalous Energy Distributions .... 83 2. Nebular Radiation 86 3. Paint Red Stars in the Orion Nebula . 95 VII. Regional Monochromatic Extinction Laws 102 A. Method 102 B. General Properties of Wideband Extinction Laws 105 C. Regional Monochromatic Curves Ill D. Properties of the Monochromatic Laws .... 121 VIII. Discussion . 126 A. Regions of 'Normal' Extinction 126 B. Regions of 'Anomalous' Extinction 127 C. Extinction and Nebulosity 131 D. Monochromatic Extinction Laws 136 IX. Conclusions 143 APPENDIX A 1^5 APPENDIX 1^7 REFERENCES 164 LIST OP FIGURES Page 1. Schematic Extinction Curve *!• 2. Normalized Extinction Curves for the Cepheus and Scorpius Regions (Johnson, 1966a) 8 3. Theoretical Extinction Curves (van de Hulst, 1949) 13 4. Normalized Filter-Cell Response Functions .... 28 5 • V-R versus B-V for 0 and B 0 Stars 48 6. V-I versus B-V for 0 and B 0 Stars 49 7. V-K versus B-V for 0 and B 0 Stars 50 8. K-L versus I-K for B 1 and Earlier-Type Stars . 53 9. Normalized Extinction Laws for the Orion East 'Belt' and NGC 2024 No. 1 71 10. Normalized Extinction Laws for M 78 A, B and the Northwestern Region 72 11. Normalized Extinction Laws for the Outer 'Sword.' HD 37061, and the Trapezium Region 73 12. Schematic Map of Extinction Regions in the I Orion Association 74 13. Orion 'Belt' Color-Magnitude Diagram—Corrected for Extinction 82 14. East-West Division of the 'Belt' Region 82 15. Infrared Photograph of the Orion 'Sword' 89 16. Infrared Photograph of the Orion Nebula 90 17. 01 Orionis 91 18. Mean Normalized Emission Spectrum Required for 'Normal1 Extinction in the Orion Trapezium .... 94 vii viii Page 19. Map of the Orion Trapezium Region (Parenago., 1954) 99 20. versus Efor 0-type Stars in Cygnus . .108 21. versus Eg_^. for 0-type Stars in Cygnus .... 109 22. Normalized Extinction Curves for Two Stars whose Color Temperatures are 3.>500 and 30,000 Degrees 110 .23. Normalized Monochromatic Extinction Lav; for the East 'Belt' Region 113 24. Normalized Monochromatic Extinction Lav/ for NGC 2024 No. 1 114 25. Normalized Monochromatic Extinction Law for the Northwestern Region 115 26. Normalized Monochromatic Extinction Law for M 78 A, B 116 27• Normalized Monochromatic Extinction Lav; for the Outer 'Sword' Region . 117 28. Normalized Monochromatic Extinction Law for HD 37061 Ho 29. Normalized Monochromatic Extinction Law for the Trapezium Region (exact fit) 119 30. Normalized Monochromatic Extinction Law for the Trapezium Region (smoothed) 120 31. versus Distance from 01 Orionis 129 32a. Extinction from Combined Distributions of Particle Sizes 139 32b. Extinction from Combined Distributions of Particle Sizes ..... 140 LIST OF TABLES Page 1. Effective Wavelengths and Reciprocal Effective Wavelengths for the Photometric Filters 26 2. UBVRI Observations 32 3. UBVRIJKL Observations 4l 4. Unreddened Early-Type Stars 44 5- Intrinsic Color Indices of Early-Type Main Sequence Stars 45 6. Intrinsic Color Indices of Early-Type Super- giants 45 7. The E^_y/Eg_^. Ratio in Orion 57 8. Color Excess Ratios 60 9. Observational Errors 65 10. Errors of Intrinsic Colors of 0 and B Stars .... 65 11. Probable Errors of Color Excesses for N Observations 68 12. Regional Extinction Data 70 13. Extinction Laws for 01 Orionis if Unseen Companions are Present 85 14. Normalized Monochromatic Extinction Data 112 15. Observed and Monochromatic Color Excess Ratios . 122 ix ABSTRACT Photoelectric photometry, covering a spectral region from X = .36 i-i to 3*4- u* is obtained for a large sample of early-type stars in the I Orion association with the photo­ metric telescopes of the Lunar and Planetary Laboratory of the University of Arizona. The observations are interpreted in terms of the interstellar extinction phenomenon. The color excesses of the stars are calculated from the observed (reddened) and intrinsic (unreddened) color indices. Nor­ malized curves revealing the wavelength dependence of the extinction are then computed. Because of the low reddeninr in many parts of the association, the errors of the extinc­ tion curves are often large. For this reason, regional mean extinction laws are determined from the data of individual stars in localized areas. A method that eliminates the use of filter effective wavelengths is then employed to obtain the corresponding monochromatic extinction laws. The extinction in a large fraction of the association is essentially 'normal.' However, two regions, one in the east 'Belt' near C Orionis and the other in the center of the Orion Nebula (NGC 1976), exhibit distinctly 'non-normal' extinction characteristics. The anomalies found in these regions are a steeper extinction gradient in the infrared x xi and a high ratio of total to selective absorption. The Orion Nebula region is studied in considerable detail.
Load more

Recommended publications
  • Arxiv:1809.07342V1 [Astro-Ph.SR] 19 Sep 2018
    Draft version September 21, 2018 Preprint typeset using LATEX style emulateapj v. 11/10/09 FAR-ULTRAVIOLET ACTIVITY LEVELS OF F, G, K, AND M DWARF EXOPLANET HOST STARS* Kevin France1, Nicole Arulanantham1, Luca Fossati2, Antonino F. Lanza3, R. O. Parke Loyd4, Seth Redfield5, P. Christian Schneider6 Draft version September 21, 2018 ABSTRACT We present a survey of far-ultraviolet (FUV; 1150 { 1450 A)˚ emission line spectra from 71 planet- hosting and 33 non-planet-hosting F, G, K, and M dwarfs with the goals of characterizing their range of FUV activity levels, calibrating the FUV activity level to the 90 { 360 A˚ extreme-ultraviolet (EUV) stellar flux, and investigating the potential for FUV emission lines to probe star-planet interactions (SPIs). We build this emission line sample from a combination of new and archival observations with the Hubble Space Telescope-COS and -STIS instruments, targeting the chromospheric and transition region emission lines of Si III,N V,C II, and Si IV. We find that the exoplanet host stars, on average, display factors of 5 { 10 lower UV activity levels compared with the non-planet hosting sample; this is explained by a combination of observational and astrophysical biases in the selection of stars for radial-velocity planet searches. We demonstrate that UV activity-rotation relation in the full F { M star sample is characterized by a power-law decline (with index α ≈ −1.1), starting at rotation periods & 3.5 days. Using N V or Si IV spectra and a knowledge of the star's bolometric flux, we present a new analytic relationship to estimate the intrinsic stellar EUV irradiance in the 90 { 360 A˚ band with an accuracy of roughly a factor of ≈ 2.
    [Show full text]
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Appendix A: Scientific Notation
    Appendix A: Scientific Notation Since in astronomy we often have to deal with large numbers, writing a lot of zeros is not only cumbersome, but also inefficient and difficult to count. Scientists use the system of scientific notation, where the number of zeros is short handed to a superscript. For example, 10 has one zero and is written as 101 in scientific notation. Similarly, 100 is 102, 100 is 103. So we have: 103 equals a thousand, 106 equals a million, 109 is called a billion (U.S. usage), and 1012 a trillion. Now the U.S. federal government budget is in the trillions of dollars, ordinary people really cannot grasp the magnitude of the number. In the metric system, the prefix kilo- stands for 1,000, e.g., a kilogram. For a million, the prefix mega- is used, e.g. megaton (1,000,000 or 106 ton). A billion hertz (a unit of frequency) is gigahertz, although I have not heard of the use of a giga-meter. More rarely still is the use of tera (1012). For small numbers, the practice is similar. 0.1 is 10À1, 0.01 is 10À2, and 0.001 is 10À3. The prefix of milli- refers to 10À3, e.g. as in millimeter, whereas a micro- second is 10À6 ¼ 0.000001 s. It is now trendy to talk about nano-technology, which refers to solid-state device with sizes on the scale of 10À9 m, or about 10 times the size of an atom. With this kind of shorthand convenience, one can really go overboard.
    [Show full text]
  • Astrometry and Optics During the Past 2000 Years
    1 Astrometry and optics during the past 2000 years Erik Høg Niels Bohr Institute, Copenhagen, Denmark 2011.05.03: Collection of reports from November 2008 ABSTRACT: The satellite missions Hipparcos and Gaia by the European Space Agency will together bring a decrease of astrometric errors by a factor 10000, four orders of magnitude, more than was achieved during the preceding 500 years. This modern development of astrometry was at first obtained by photoelectric astrometry. An experiment with this technique in 1925 led to the Hipparcos satellite mission in the years 1989-93 as described in the following reports Nos. 1 and 10. The report No. 11 is about the subsequent period of space astrometry with CCDs in a scanning satellite. This period began in 1992 with my proposal of a mission called Roemer, which led to the Gaia mission due for launch in 2013. My contributions to the history of astrometry and optics are based on 50 years of work in the field of astrometry but the reports cover spans of time within the past 2000 years, e.g., 400 years of astrometry, 650 years of optics, and the “miraculous” approval of the Hipparcos satellite mission during a few months of 1980. 2011.05.03: Collection of reports from November 2008. The following contains overview with summary and link to the reports Nos. 1-9 from 2008 and Nos. 10-13 from 2011. The reports are collected in two big file, see details on p.8. CONTENTS of Nos. 1-9 from 2008 No. Title Overview with links to all reports 2 1 Bengt Strömgren and modern astrometry: 5 Development of photoelectric astrometry including the Hipparcos mission 1A Bengt Strömgren and modern astrometry ..
    [Show full text]
  • A New Form of Estimating Stellar Parameters Using an Optimization Approach
    A&A 532, A20 (2011) Astronomy DOI: 10.1051/0004-6361/200811182 & c ESO 2011 Astrophysics Modeling nearby FGK Population I stars: A new form of estimating stellar parameters using an optimization approach J. M. Fernandes1,A.I.F.Vaz2, and L. N. Vicente3 1 CFC, Department of Mathematics and Astronomical Observatory, University of Coimbra, Portugal e-mail: [email protected] 2 Department of Production and Systems, University of Minho, Portugal e-mail: [email protected] 3 CMUC, Department of Mathematics, University of Coimbra, Portugal e-mail: [email protected] Received 17 October 2008 / Accepted 27 May 2011 ABSTRACT Context. Modeling a single star with theoretical stellar evolutionary tracks is a nontrivial problem because of a large number of unknowns compared to the number of observations. A current way of estimating stellar age and mass consists of using interpolations in grids of stellar models and/or isochrones, assuming ad hoc values for the mixing length parameter and the metal-to-helium enrichment, which is normally scaled to the solar values. Aims. We present a new method to model the FGK main-sequence of Population I stars. This method is capable of simultaneously estimating a set of stellar parameters, namely the mass, the age, the helium and metal abundances, the mixing length parameter, and the overshooting. Methods. The proposed method is based on the application of a global optimization algorithm (PSwarm) to solve an optimization problem that in turn consists of finding the values of the stellar parameters that lead to the best possible fit of the given observations.
    [Show full text]
  • Cosmos: a Spacetime Odyssey (2014) Episode Scripts Based On
    Cosmos: A SpaceTime Odyssey (2014) Episode Scripts Based on Cosmos: A Personal Voyage by Carl Sagan, Ann Druyan & Steven Soter Directed by Brannon Braga, Bill Pope & Ann Druyan Presented by Neil deGrasse Tyson Composer(s) Alan Silvestri Country of origin United States Original language(s) English No. of episodes 13 (List of episodes) 1 - Standing Up in the Milky Way 2 - Some of the Things That Molecules Do 3 - When Knowledge Conquered Fear 4 - A Sky Full of Ghosts 5 - Hiding In The Light 6 - Deeper, Deeper, Deeper Still 7 - The Clean Room 8 - Sisters of the Sun 9 - The Lost Worlds of Planet Earth 10 - The Electric Boy 11 - The Immortals 12 - The World Set Free 13 - Unafraid Of The Dark 1 - Standing Up in the Milky Way The cosmos is all there is, or ever was, or ever will be. Come with me. A generation ago, the astronomer Carl Sagan stood here and launched hundreds of millions of us on a great adventure: the exploration of the universe revealed by science. It's time to get going again. We're about to begin a journey that will take us from the infinitesimal to the infinite, from the dawn of time to the distant future. We'll explore galaxies and suns and worlds, surf the gravity waves of space-time, encounter beings that live in fire and ice, explore the planets of stars that never die, discover atoms as massive as suns and universes smaller than atoms. Cosmos is also a story about us. It's the saga of how wandering bands of hunters and gatherers found their way to the stars, one adventure with many heroes.
    [Show full text]
  • MAS Mentoring Project Overview 2020
    Macarthur Astronomical Society Student Projects in Astronomy A Guide of Teachers and Mentors 2020 (c) Macarthur Astronomical Society, 2020 DRAFT The following Project Overviews are based on those suggested by Dr Rahmi Jackson of Broughton Anglican College. The Focus Questions and Issues section should be used by teachers and mentors to guide students in formulating their own questions about the topic. References to the NSW 7-10 Science Syllabus have been included. Note that only those sections relevant are included. For example, subsections a and d may be used, but subsections b and c are omitted as they do not relate to this topic. A generic risk assessment is provided, but schools should ensure that it aligns with school- based policies. MAS Student Projects in Astronomy page 1 Project overviews Semester 1, 2020: Project Stage Technical difficulty 4 5 6 1 The Moons of Jupiter X X X Moderate to high (extension) NOT available Semester 1 2 Astrophotography X X X Moderate to high 3 Light pollution X X Moderate 4 Variable stars X X Moderate to high 5 Spectroscopy X X High 6 A changing lunarscape X X Low to moderate Recommended project 7 Magnitude of stars X X Moderate to high Recommended for technically able students 8 A survey of southern skies X X Low to moderate 9 Double Stars X X Moderate to high 10 The Phases of the Moon X X Low to moderate Recommended project 11 Observing the Sun X X Moderate MAS Student Projects in Astronomy page 2 Project overviews Semester 2, 2020: Project Stage Technical difficulty 4 5 6 1 The Moons of Jupiter
    [Show full text]
  • The Chemical Composition of Solar-Type Stars and Its Impact on the Presence of Planets
    The chemical composition of solar-type stars and its impact on the presence of planets Patrick Baumann Munchen¨ 2013 The chemical composition of solar-type stars and its impact on the presence of planets Patrick Baumann Dissertation der Fakultat¨ fur¨ Physik der Ludwig-Maximilians-Universitat¨ Munchen¨ durchgefuhrt¨ am Max-Planck-Institut fur¨ Astrophysik vorgelegt von Patrick Baumann aus Munchen¨ Munchen,¨ den 31. Januar 2013 Erstgutacher: Prof. Dr. Achim Weiss Zweitgutachter: Prof. Dr. Joachim Puls Tag der mündlichen Prüfung: 8. April 2013 Zusammenfassung Wir untersuchen eine mogliche¨ Verbindung zwischen den relativen Elementhaufig-¨ keiten in Sternatmospharen¨ und der Anwesenheit von Planeten um den jeweili- gen Stern. Um zuverlassige¨ Ergebnisse zu erhalten, untersuchen wir ausschließlich sonnenahnliche¨ Sterne und fuhren¨ unsere spektroskopischen Analysen zur Bestim- mung der grundlegenden Parameter und der chemischen Zusammensetzung streng differenziell und relativ zu den solaren Werten durch. Insgesamt untersuchen wir 200 Sterne unter Zuhilfenahme von Spektren mit herausragender Qualitat,¨ die an den modernsten Teleskopen gewonnen wurden, die uns zur Verfugung¨ stehen. Mithilfe der Daten fur¨ 117 sonnenahnliche¨ Sterne untersuchen wir eine mogliche¨ Verbindung zwischen der Oberflachenh¨ aufigkeit¨ von Lithium in einem Stern, seinem Alter und der Wahrscheinlichkeit, dass sich ein oder mehrere Sterne in einer Um- laufbahn um das Objekt befinden. Fur¨ jeden Stern erhalten wir sehr exakte grundle- gende Parameter unter Benutzung einer sorgfaltig¨ zusammengestellten Liste von Fe i- und Fe ii-absorptionslinien, modernen Modellatmospharen¨ und Routinen zum Erstellen von Modellspektren. Die Massen und das Alter der Objekte werden mithilfe von Isochronen bestimmt, was zu sehr soliden relativen Werten fuhrt.¨ Bei jungen Sternen, fur¨ die die Isochronenmethode recht unzuverlssig¨ ist, vergleichen wir verschiedene alternative Methoden.
    [Show full text]
  • Nucleosynthesis in the Stellar Systems Omega Centauri And
    CSIRO PUBLISHING Publications of the Astronomical Society of Australia, 2011, 28, 28–37 www.publish.csiro.au/journals/pasa Nucleosynthesis in the Stellar Systems v Centauri and M22 G. S. Da CostaA,C and A. F.MarinoB A Research School of Astronomy & Astrophysics, Australian National University, Mt Stromlo Observatory, via Cotter Rd, Weston, ACT 2611, Australia B Dipartimento di Astronomia, Universita` di Padova, vicolo dell’Osservatorio 2, I-35122 Padova, Italy C Corresponding author. Email: [email protected] Received 2010 August 3, accepted 2010 September 7 Abstract: The stellar system v Centauri (v Cen) is well known for the large range in elemental abundances among its member stars. Recent work has indicated that the globular cluster M22 (NGC 6656) also possesses an internal abundance range, albeit substantially smaller than that in v Cen. Here we compare, as a function of [Fe/H], element-to-iron ratios in the two systems for a number of different elements using data from abundance analyses of red giant branch stars. It appears that the nucleosynthetic enrichment processes were very similar in these two systems despite the substantial difference in total mass. Keywords: globular clusters: general — globular clusters: individual (M22, v Cen) — stars: abundances 1 Introduction tidally disrupted by the Milky Way (e.g., Freeman 1993). The stellar system v Centauri (v Cen) has been known for Bekki & Freeman (2003), for example, have shown that a long time to be different from most other Galactic this is dynamically plausible. The different evolutionary globular clusters because its member stars exhibit a wide environment may then have allowed additional chemical range in the abundance of heavier elements such as iron processes that do not occur in ‘regular’ globular clusters (e.
    [Show full text]
  • ASTR110G Astronomy Laboratory Exercises C the GEAS Project 2020
    ASTR110G Astronomy Laboratory Exercises c The GEAS Project 2020 ASTR110G Laboratory Exercises Lab 1: Fundamentals of Measurement and Error Analysis ...... ....................... 1 Lab 2: Observing the Sky ............................... ............................. 35 Lab 3: Cratering and the Lunar Surface ................... ........................... 73 Lab 4: Cratering and the Martian Surface ................. ........................... 97 Lab 5: Parallax Measurements and Determining Distances ... ....................... 129 Lab 6: The Hertzsprung-Russell Diagram and Stellar Evolution ..................... 157 Lab 7: Hubble’s Law and the Cosmic Distance Scale ........... ..................... 185 Lab 8: Properties of Galaxies .......................... ............................. 213 Appendix I: Definitions for Keywords ..................... .......................... 249 Appendix II: Supplies ................................. .............................. 263 Lab 1 Fundamentals of Measurement and Error Analysis 1.1 Introduction This laboratory exercise will serve as an introduction to all of the laboratory exercises for this course. We will explore proper techniques for obtaining and analyzing data, and practice plotting and analyzing data. We will discuss a scientific methodology for conducting exper- iments in which we formulate a question, predict the behavior of the system based on likely solutions, acquire relevant data, and then compare our predictions with the observations. You will have a chance to plan a short experiment,
    [Show full text]
  • Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B
    Cambridge University Press 978-0-521-89954-3 - Stars and Their Spectra: An Introduction to the Spectral Sequence Second Edition James B. Kaler Index More information Star index Stars are arranged by the Latin genitive of their constellation of residence, with other star names interspersed alphabetically. Within a constellation, Bayer Greek letters are given first, followed by Roman letters, Flamsteed numbers, variable stars arranged in traditional order (see Section 1.11), and then other names that take on genitive form. Stellar spectra are indicated by an asterisk. The best-known proper names have priority over their Greek-letter names. Spectra of the Sun and of nebulae are included as well. Abell 21 nucleus, see a Aurigae, see Capella Abell 78 nucleus, 327* ε Aurigae, 178, 186 Achernar, 9, 243, 264, 274 z Aurigae, 177, 186 Acrux, see Alpha Crucis Z Aurigae, 186, 269* Adhara, see Epsilon Canis Majoris AB Aurigae, 255 Albireo, 26 Alcor, 26, 177, 241, 243, 272* Barnard’s Star, 129–130, 131 Aldebaran, 9, 27, 80*, 163, 165 Betelgeuse, 2, 9, 16, 18, 20, 73, 74*, 79, Algol, 20, 26, 176–177, 271*, 333, 366 80*, 88, 104–105, 106*, 110*, 113, Altair, 9, 236, 241, 250 115, 118, 122, 187, 216, 264 a Andromedae, 273, 273* image of, 114 b Andromedae, 164 BDþ284211, 285* g Andromedae, 26 Bl 253* u Andromedae A, 218* a Boo¨tis, see Arcturus u Andromedae B, 109* g Boo¨tis, 243 Z Andromedae, 337 Z Boo¨tis, 185 Antares, 10, 73, 104–105, 113, 115, 118, l Boo¨tis, 254, 280, 314 122, 174* s Boo¨tis, 218* 53 Aquarii A, 195 53 Aquarii B, 195 T Camelopardalis,
    [Show full text]
  • 1910Ap J 31 8B on a GREAT NEBULOUS REGION
    8B 31 J 1910Ap ON A GREAT NEBULOUS REGION AND ON THE QUES- TION OF ABSORBING MATTER IN SPACE AND THE TRANSPARENCY OF THE NEBULAE By E. E. BARNARD While photographing the region of the great nebula of p Ophiuchi (which I had found with the Willard lens) at the Lick Observatory in 1893, the plates with the small lantern lens (ii inches diameter, also attached to the Willard mounting) showed a remarkable nebula involving the 4.5 magnitude star v Scorpii (Plate I). It had not been noticed on the Willard lens photograph, where it was very faint and near the edge of the plate. The discovery of this object therefore is due to the small lantern lens. Roughly this nebula is bounded by the figure formed by the follow- ing places (for 1855.0) : a S f j i5h 59m —180 2o/ 16 4 —18 o and 16 10 —21 00 16 16 —18 50 In its fainter portions it involves to the southeast the stars B. D. i9?4357, —19?4359, and — i9?436i. The last two are in a dense nebulous mass in which on the north following side close to the stars are a thin dark lane and a narrow strip of brighter nebulosity. These two stars are joined to —19?4357, which is itself nebulous, by a thin thread of nebulosity which is well shown in Plate II A. North and following these objects are dark regions where there are apparently very few stars. The extensions of this great nebula reach to, and in a feeble manner connect with, the great nebula of p Ophiuchi.
    [Show full text]