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| University Microfilms, a XEROX Company , Ann Arbor, Michigan I THE UPPER CENTAURUS ASSOCIATION Item Type text; Dissertation-Reproduction (electronic) Authors Glaspey, John Warren, 1944- 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 06/10/2021 14:40:24 Link to Item http://hdl.handle.net/10150/287700 71-21,990 GLASPEY, John Warren, 1944- THE UPPER CENTAURUS ASSOCIATION. The University of Arizona, Ph.D., 1971 Astronomy | University Microfilms, A XEROX Company , Ann Arbor, Michigan i THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED THE UPPER CENTAURUS ASSOCIATION by John Warren Glaspey 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 7 1 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE I hereby recommend that this dissertation prepared under my direction by John. Warren Glaspev entitled The Upper Centaurus Association be accepted as fulfilling the dissertation requirement of the degree of Doctor of Philosophy (0 Date 7 After inspection of the final copy of the dissertation, the follov/ing members of the Final Examination Committee concur in its approval and recommend its acceptance:* f~el /Qj / 7 7 t \All^VUA^J/( , (.A ftwh I 0 i 0 , ^ —- _ja 7/ [<D ifl/ 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 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 allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole 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. SIGNED: ACKNOWLEDGMENTS I wish to express my gratitude to the following individuals, who have helped me so much during the course of this investigation: Dr. Victor Blanco and his staff at the Cerro Tololo Inter-American Observatory, who provided me with assistance during my observing run and who helped make my visit such a pleasant one. Dr. Nicholas Mayall, Dr. Arthur Hoag, and the staff of the Kitt Peak National Observatory, who willingly made many of the Observatory facilities available. Dr. John Graham and Mrs. Jeannette Barnes, for their assistance and encouragement at all phases of this investigation. Mr. Ed Howell, who provided me with photographic assistance whenever it was needed. Dr. David Crawford, for his sound advice and continuous encouragement, and for so generously supplying me with a great deal of unpublished material. Dr. Bart Bole, for serving so ably as my advisor during this investigation, for prodding and urging me on whenever needed, and for generously giving his time and energy to open the doors that led to a successful conclu­ sion of this investigation. iii iv My wife, Lynn, for helping ine in countless ways, and for enduring the many follies of graduate work. TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS vii LIST OF TABLES x ABSTRACT xii CHAPTER 1. INTRODUCTION AND HISTORICAL REVIEW 1 Analysis of the Group Motion 3 Relationship With Gould's Belt 7 Subgroups in Associations 11 Summary of Objectives ..... l6 2. OBSERVATIONS AND DATA REDUCTIONS l8 Objective Prism Survey 18 Classifications from Slit Spectra .... 27 uvby Photometric Reductions 30 Hp Photometry Reductions 36 Radial Velocity Summary 45 3. B STAR ANALYSIS 57 Reddening Corrections 57 Comparison With Spectral Classification . 64 The m^-Index Discrepancy 64 Absolute Magnitude Calibration 82 The (3, (u-b)0 Diagrams 90 4. AGE DETERMINATION Effective Temperature Calibration .... 94 Bolometric Corrections 100 Zero Age Main Sequence 101 Conversion from AM^oi to 3 103 Comparison of Models to Observations . 104 Summary 109 v vi TABLE OF CONTENTS—Continued CHAPTER Page 5. AO STAR ANALYSIS 110 The Zero Age Main Sequence for AO Stars Ill Determination of Color Excesses Il6 6. A AND F STAR ANALYSIS 128 Evolutionary Effects . 129 Absolute Magnitudes and Distance Moduli 136 The Metallicity Index 139 7. DISCUSSION AND CONCLUSIONS 1^3 Motions Analysis 1^3 Proper Motions l44 Radial Velocity Analysis 15^ Distance Modulus Criteria for Upper Scorpius Stars l60 The Color-Magnitude Diagram for Upper Scorpius 162 Distance Modulus Criteria for Centaurus Stars 165 The Color-Magnitude Diagram for Upper Centaurus 167 Discussion of Age Estimates 169 Peculiar Stars 175 Summary 179 Suggestions for Future Work l8l REFERENCES 184 LIST OF ILLUSTRATIONS Figure Page 1. Areal Distribution of Faint Stars in Scorpius and Centaurus 21 2. Areal Distribution of Faint Stars Selected for Study 22 3. Comparison of Objective Prism Classifica­ tions with (b-y) 23 o 4. Comparison of HD Classifications with (b-y) ........... 24 J o 5. Comparison of Objective Prism Classifica­ tions with IiD Classifications 25 6. Comparison of Objective Prism Classifica­ tions with Photometric Classifications ... 26 7. Comparison of Objective Prism Classifica­ tions with Slit-Spectra Classifications . 28 8. Comparison of Slit-Spectra Classifications with (b-y) 29 o 9. Four-Color Filter Transmission Curves .... 31 10. Fi-equencies of Radial Velocity Ranges, (V - V . ) 48 max nun 11. Areal Distribution of E(b-y) of B-Type Stars 65 12. cQ, Sp(MIC) Diagram for B-Type Stars 71 13 • P, Sp(MK) Diagram for B-Type Stars 72 l4. m0, Sp(MIC) Diagram for B-Type Stars 73 15* c •, mQ Diagram for B-Type Stars 74 l6. Anij , E(b-y) Diagram for B-Type Stars in Upper Scorpius 77 vii viii LIST OF ILLUSTRATIONS--Continued Figure Page 17• Ami, v sin i Diagram for B-Type Stars in Upper Scorpius 8l 18. Mv(Bertiau) , (3 Diagram for B-Type Stars ... 83 19. M (Bertiau), M,,(p) Diagram for B-Type Stars . 8k 20. V0, P Diagram for B-Type Stars 86 21. V0, (u-b)Q Diagram for B-Type Stars 87 22. Frequencies of B Star Distance Moduli .... 89 23 • (3, Diagrams for Subgroups in the Association 91 24. Temperature-Color Calibrations 96 25 • Main Sequence Relations in the (3, (u-b) Diagram 102 26. Evolutionary Tracks and Isochrones for X = 0.70, Z = 0.02 105 27• Isochrones for Different Compositions in the (3, (u-b)Q Diagram 107 28. |3, (b-y) Diagram for Bright AO Stars Il4 29. c^, (b-y) Diagram for Bright AO Stars .... 115 30. [m^], (b-y) Relation fox- Young AO Stars . 117 31. cQ, (b-y)G Diagram for AO Stars in Scorpius and Centaur us 120 32. Areal Distribution of E(b-y) for AO Stars . 125 33. Frequencies of Distance Moduli for AO Stars 126 34. Areal Distribution of E(b-y) for AF Stars . 133 c 35• oi (b-y)0 Diagram for AF Stars in Scorpius and Centaurus 135 ix LIST OP ILLUSTRATIONS—Continued Figure Page 36. Frequencies of Distance Moduli for AF Stars 138 37. m0, (b-y)Q Diagram for AF Stars in Scorpius and Centaur us ikO 38. Frequencies of Proper Motions in Centaurus . 152 39. Radial Velocities Versus Galactic Longitude for B-Type Stars ......... 157 '±0. Radial Velocities Versus Galactic Longitude fox" A- and F-Type Stars 159 41. V , Mv Diagram for Upper Scorpius Stars . l6l 42. V , (b-y)0 Diagram for Upper Scorpius Stars 163 ^3. VD, M Diagram for Centaurus Stars 166 kk. V (b-y)Q Diagram for Upper Centaurus Stars l68 45. P, (u-b)0 Diagrams for Young Open Clusters and Associations ......... 172 LIST OF TABLES Table Page 1. Four-Color Extinction Coefficients . 33 2. R.M.S. Errors from uvby Reductions 35 3. Photometry of Stars in Scorpius and Centaur us 37 4. 11(3 Standard Stars 43 5. RMS Errors from Hp Reductions 44 6. Stars Having Only (3 Observations 46 7. Radial Velocity Observations of Standard Velocity Stars 50 8. Radial Velocity Observations of Stars in Scorpius and Centaurus 51 9. Additional Photometric Data for B-Type Stars in Lower Centaurus 58 10. Additional. Photometric Data for B-Type Stars in Upper Centaurus .......... 59 11. Additional Photometric Data for B-Type Stars in Scorpius 6l 12. Additional II|3 Photometric Data for B-Type Stars in Scorpius ....' 63 3-3 • Unreddened Photometric Colors in Lower Centaurus ..... 66 l4. Unreddened Photometric Colors of B-Type Stars in Upper Centaurus 67 15« Unreddened Photometric Colors of B-Type Stars in Upper Scorpius 69 16. Changes in m.. and c1 for Artificial Binaries 80 x XI LIST OF TABLES—Continued Table Page 17. Adopted Calibrations of log T and B.C . 97 18. AO Calibration 112 19. Unreddened Photometric Indices for Unevolved AO Stars ..... 122 20. Unreddened Photometric Indices for Evolved AO Stars 124 21. Unreddened Photometric Colors for A and P Stars 130 22. Proper Motions from the Smithsonian Catalog . l46 23* Published Radial Velocities ......... 155 24. Possible Members in Upper Scorpius l64 25. Possible Non-Members Considered to be Members by Garrison 165 26. Possible Members in Upper Centaurus 170 27- Cluster* Age Estimates 174 ABSTRACT The Scorpio-Centaurus association is one of the neai"est gi~oups of young B-type stars to show common streaming motions, and as such has played an important role in the determination of absolute magnitudes of B-type stars.
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