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MINIMO: a Search for Mini Proper Motion Stars in the Southern Sky

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MINIMO: a Search for Mini Proper Motion Stars in the Southern Sky Georgia State University ScholarWorks @ Georgia State University Physics and Astronomy Theses Department of Physics and Astronomy 5-3-2007 MINIMO: A Search for Mini Proper Motion Stars in the Southern Sky Charlie Thomas Finch Follow this and additional works at: https://scholarworks.gsu.edu/phy_astr_theses Part of the Astrophysics and Astronomy Commons, and the Physics Commons Recommended Citation Finch, Charlie Thomas, "MINIMO: A Search for Mini Proper Motion Stars in the Southern Sky." Thesis, Georgia State University, 2007. https://scholarworks.gsu.edu/phy_astr_theses/2 This Thesis is brought to you for free and open access by the Department of Physics and Astronomy at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Physics and Astronomy Theses by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. MINIMO: A SEARCH FOR MINI PROPER MOTION STARS IN THE SOUTHERN SKY by Charlie T. Finch Under the Direction of Todd J. Henry Abstract I report 1684 new proper motion systems in the southern sky (declinations ¡90± to ¡47±) with 000:50 yr¡1 > ¹ ¸ 000:18 yr¡1. This e®ort is a continuation of the SuperCOSMOS-RECONS (SCR) proper motion search to lower proper motions than reported in Hambly et al. (2004); Henry et al. (2004); Subasavage et al. (2005a,b). Distance estimates are presented for the new systems, assuming that all stars are on the main sequence. I ¯nd that 34 systems are within 25 pc, including three systems | SCR 0838-5855, SCR 1826-6542, and SCR 0630-7643AB | anticipated to be within 10 pc. These mini-motion (MINIMO) discoveries constitute a more than ten-fold increase in new systems found in the same region of sky searched for systems with ¹ ¸ 000:50 yr¡1, suggesting a happy hunting ground for new nearby slower proper motion systems in the region just north (declinations ¡47± to 0±), much of which has not been rigorously searched during previous e®orts. Index Words: Stars: Proper Motion, Solar Neighborhood, Distances, Statistics, Sur- veys, Astrometry MINIMO: A SEARCH FOR MINI PROPER MOTION STARS IN THE SOUTHERN SKY by Charlie T. Finch A Thesis Presented in Partial Ful¯llment of Requirements for the Degree of Master of Science in the College of Arts and Sciences Georgia State University 2007 Copyright by Charlie T. Finch 2007 MINIMO: A SEARCH FOR MINI PROPER MOTION STARS IN THE SOUTHERN SKY by Charlie T. Finch Major Professor: Todd J. Henry Committee: Douglas R. Gies Harold A. McAlister Electronic Version Approved: O±ce of Graduate Studies College of Arts & Sciences Georgia State University May 2007 iv { 0 { Dedication This thesis is dedicated in loving memory of my grandfather Charlie Clyde Smith, to whom I not only inherited my name but also my good looks. I miss you... v { 0 { Acknowledgments Probably the hardest part of a thesis is trying to acknowledge everyone who has contributed to and made this part of my life more enjoyable during the process. It is a pleasure to show my gratitude to the many people who have made this thesis possible. My family has always been a great support throughout my life and without them I could have never made it to where I am today. I would like to thank my parents for their encouragement and support, both emotional and monetary, and their uncanny ability to put up with me. I also would like to thank my grandfather for whom this thesis is dedicated for always believing in me and everything that I do. My thanks also go out to the rest of my family who have been the backbone of my support. Many thanks go out to all my friends who have supported me in all my decisions and have always been there for me. In particular, I would like to thank Nicole Geiger, without her friendship and support I would have never ¯nished my degree. To my girlfriend Amelia Gri±th, I would like to say thank you for putting up with my long nights of working and for your encouragement. I need to thank Georgia State University for giving me the opportunity to explore the research opportunities available at this institution. I give my gratitude to Dr. Douglas Gies and Dr. Harold McAlister for agreeing to serve on my thesis committee and thoroughly reading through my thesis for suggestions. To my supervisor Dr. Todd Henry, I give many thanks for giving me the opportunity to prove that this thesis was not beyond my reach and without whom this thesis would have not been possible. vi Without the support, encouragement and friendship from the many faculty and sta® at the Georgia State Physics and Astronomy department, time spent on this thesis would not have been as manageable. I am honored to have had the opportunity to work with them and thank them for everything they have contributed. Finally I would like to thank Nigel C. Hambly, John P. Subasavage and Jao Wei-Chun for their many contributions that have made this search possible. vii { 0 { Contents Acknowledgments . v Tables . ix Figures . x Abbreviations and Acronyms . xii 1 Introduction . 1 1.1 Early Discoveries . 2 1.1.1 Barnard's Star . 2 1.1.2 Kapteyn's Star . 3 1.1.3 Groombridge 1830 . 4 1.2 Proper Motion Surveys . 5 1.2.1 Why Are They Important? . 5 1.2.2 Historical Beginnings . 6 1.2.3 Luyten & Giclas . 7 1.2.4 Surveys Relevant to This Search . 8 1.3 Goals and Motivation . 10 2 Search Criteria . 12 3 Comparison to Previous Proper-Motion Surveys . 20 4 Data . 22 5 Photometric and Spectroscopic Observations of the Nearby Sample 28 5.1 Photometry . 28 5.2 Spectroscopy . 32 6 Analysis . 35 6.1 Color-Magnitude Diagram . 35 6.2 Reduced Proper Motion Diagram . 37 viii 6.3 New Common Proper Motion Systems . 40 6.4 Comments on Individual MINIMO Systems . 46 7 Discussion . 47 References . 52 Appendix . 56 ix { 0 { Tables 2.1 Discovery Statistics for Entire SCR Sample . 19 3.1 Number of NLTT-Type Objects Discovered South of Declination ¡47± 21 4.1 Characteristics of New SCR Systems Estimated to be Nearer than 25 Parsecs and New White Dwarf Candidates with 000:50 yr¡1 > ¹ ¸ 000:18 yr¡1 from ¡90± < ± ·¡47± ....................... 25 5.1 Photometry, Spectral Types and CCD Distance Estimates for MIN- IMO Systems Estimated to be Nearer than 25 pc with 000:50 yr¡1 > ¹ ¸ 000:18 yr¡1 from ¡90± < ± ·¡47± . 31 6.1 Common Proper Motion Systems . 42 7.1 Distance Estimate Statistics for SCR Systems . 50 x { 0 { Figures 2.1 Plate coverage of the sky included in the MINIMO search. White boxes indicate plates that were excluded, primarily due to crowding in the Galactic Plane, LMC, and SMC, or because of an insu±cient spread in plate epochs. Plates 179, 227, and 228 are included because they were searched for objects with 000:50 yr¡1 > ¹ ¸ 000:40 yr¡1 but not for objects with 000:40 yr¡1 > ¹ ¸ 000:18 yr¡1. 17 2.2 Hit Rate percentage of true proper motion objects (real proper motion objects / total candidates extracted) for the entire SCR sample having ¹ ¸ 000:18 yr¡1 south of ¡47±. Horizontal bars show the proper motion bins adopted, while vertical lines delineate the three individual SCR samples | MOTION, SLOWMO and MINIMO. 18 4.1 Comparison of NLTT, Hipparcos, and SCR proper motions and po- sition angles. The solid lines indicate perfect agreement. Note that proper motion data for NLTT is quantized south of ¡45±. 27 5.1 Spectral plots of new SCR discoveries estimated to be within 25 pc. Note that spectra of SCR 0630-7643AB, SCR 1240-8116, and SCR 1245-5506 were taken with a 200 slit width and may have minor flux calibration problems. 34 6.1 Color-apparent magnitude diagram for SCR systems (open circles) and known systems (small points) with 000:50 yr¡1 > ¹ ¸ 000:18 yr¡1 from ± ± ¡90 < ± ·¡47 . Data points below our search cuto® of R59F = 16.5 are CPM companions noticed during the blinking process. 36 6.2 Reduced proper motion diagram for SCR systems (open circles) and known systems (small points) with 000:50 yr¡1 > ¹ ¸ 000:18 yr¡1 from ¡90± < ± ·¡47±. The arbitrary dotted line separates the white dwarfs from the subdwarfs. Triangles denote previously known white dwarfs. 39 xi 6.3 Comparison of proper motions for components in multiple systems. Proper motions from the automated SCR search are denoted by ¯lled circles and proper motions manually obtained through SuperCOSMOS are denoted by open circles. The solid line indicates perfect agreement between the two and the dashed lines represent conservative limits of 000:20 yr¡1 based on our uncertanties. 44 6.4 Comparison of position angles for components in multiple systems. Position angles from the automated SCR search are denoted by ¯lled circles and position angles manually obtained through SuperCOSMOS are denoted by open circles. The solid line indicates perfect agreement between the two and the dashed lines represent conservative limits of 5.0 degrees based on our uncertainties. 45 7.1 Sky distribution of SCR systems with ¹ ¸ 000:18 yr¡1. Open circles denote SCR discoveries from this search and small ¯lled circles indicate SCR discoveries from past papers. The curve represents the Galactic plane. 49 7.2 Histogram showing the number of new proper motion discoveries in 000:01 yr¡1 bins for the entire MINIMO sample (light shade) and the number of those objects having distance estimates within 50 pc (dark shade). 51 xii { 0 { Abbreviations and Acronyms APS Automated Plate Scanner CCD Charge-Coupled Device CDC Control Data Corporation CPM Common Proper Motion CTIO Cerro Tololo Inter-American Observatory ESO European Southern Observatory FWHM Full-Width Half-Maximum GSC Guide Star Catalog HPM High Proper Motion HST Hubble Space
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