The Sky is Your Laboratory Advanced Astronomy Projects for Amateurs Robert K. Buchheim The Sky is Your Laboratory Advanced Astronomy Projects for Amateurs Published in association with PPraxisraxis PPublishiublishingng Chichester, UK Robert K. Buchheim Coto de Caza California USA SPRINGER±PRAXIS BOOKS IN POPULAR ASTRONOMY SUBJECT ADVISORY EDITOR: John Mason B.Sc., M.Sc., Ph.D. ISBN 978-0-387-71822-4 Springer Berlin Heidelberg New York Springer is part of Springer-Science + Business Media (springer.com) Library of Congress ControlNumber: 2007923856 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. # Praxis Publishing Ltd, Chichester, UK, 2007 Printed in Germany The use of generaldescriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a speci®c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for generaluse. Cover design: Jim Wilkie Cover image: Wally Pacholka Project management: Originator Publishing Services Ltd, Gt Yarmouth, Norfolk, UK Printed on acid-free paper Astronomy is one of the few sciences where the experienced amateur can conduct original research, and contribute to professional studies. If you are wondering whether you can do something useful, valuable, and permanent with your observa- tional skills, the answer is, ``Yes, you can!'' You can do this: you are capable of contributing to astronomical science. This book will show you how to conduct observational research projects during your nights under the stars. I hope that it will motivate you to try. Bob Buchheim Coto de Caza, California, 2007 Contents Acknowledgements...................................... xiii List of ®gures ........................................ xv List of abbreviations and acronyms ........................... xix List of products and trademarks ............................. xxiii Introduction .......................................... xxv 1 Meteor studies ..................................... 1 1.1 Introduction ................................... 1 1.2 Project A: visual counts of major meteor showers .......... 6 1.2.1 Equipment required ........................ 8 1.2.2 Conducting the observations and recording the data . 8 1.2.3 Reducing, analyzing, and submitting your results ..... 11 1.3 Project B: characterization of minor meteor showers ........ 11 1.3.1 Equipment needed ......................... 12 1.3.2 Conducting the observations and recording the data . 13 1.3.3 Reducing, analyzing, and submitting your results ..... 14 1.4 Project C: characterizing sporadic meteors, and discovering un- recognized showers .............................. 17 1.4.1 Equipment needed ......................... 18 1.4.2 Conducting the observations and recording the data . 19 1.4.3 Reducing, analyzing, and submitting your results ..... 19 1.5 Meteor parallax and altitude determination .............. 21 1.6 Automating your meteor observations ................. 22 1.7 Radio meteor monitoring .......................... 22 1.8 Coordinating organizations: AMS and IMO ............. 26 1.9 References .................................... 26 viii Contents 2 Occultations ....................................... 27 2.1 Project D: lunar occultation timing ................... 27 2.1.1 Equipment needed ......................... 30 2.1.2 Observing lunar occultations and recording the data . 31 2.1.3 Reducing and analyzing your results ............. 35 2.1.4 Reporting your results ...................... 38 2.2 Project E: grazing lunar occultations .................. 40 2.2.1 Equipment needed ......................... 40 2.2.2 Planning for a grazing occultation expedition ....... 42 2.2.3 Conducting the observations .................. 51 2.2.4 Reducing, analyzing, and reporting the results ....... 52 2.3 Project F: asteroid occultation timing .................. 54 2.3.1 Equipment needed ......................... 58 2.3.2 Preparing for the observation .................. 59 2.3.3 Conducting the observation ................... 63 2.3.4 Reducing, analyzing, and reporting asteroid occultation timings ................................ 70 2.4 International Occultation Timing Association ............. 71 2.5 Additional reading and resources ..................... 72 2.6 References .................................... 74 3 Visual variable star observing ............................ 75 3.1 Project G: visual observation of variable stars ............ 75 3.1.1 Equipment needed ......................... 78 3.1.2 The importance of standardized observing methods . 83 3.1.3 Making the observations ..................... 83 3.1.4 Human factors considerations . .............. 88 3.1.5 Recording your observations .................. 90 3.1.6 Reporting your observations .................. 91 3.2 Coordinating Organizations: AAVSO, BAA-VSS, and AFOEV . 93 3.3 References .................................... 93 4 CCD photometry .................................... 95 4.1 Introduction ................................... 95 4.2 General principles of aperture photometry . .............. 100 4.2.1 Selection of comp stars ...................... 103 4.2.2 Software packages for photometry .............. 103 4.2.3 Absolute vs. differential photometry .............. 104 4.3 Project H: CCD photometry of variable stars ............ 105 4.3.1 Equipment needed ......................... 106 4.3.2 Conducting the observations .................. 107 4.3.3 Reducing and analyzing your observations ......... 109 4.3.4 Submitting your observations .................. 112 4.3.5 Comparing your observations with other's data ...... 114 4.3.6 Rapidly-changing (short-period) variable stars ....... 115 Contents ix 4.4 Project I: determining asteroid lightcurves ............... 116 4.4.1 Equipment needed ......................... 118 4.4.2 Making the observations ..................... 119 4.4.3 Reducing and analyzing your observations ......... 122 4.4.4 Reporting your results ...................... 136 4.4.5 The challenge of long-period asteroids ............ 137 4.4.6 Choosing your target ....................... 138 4.4.7 Collaborations: the CALL website .............. 139 4.5 Signal, noise, and photometric accuracy ................ 141 4.5.1 ``Signal'' de®ned .......................... 142 4.5.2 Gain of CCD sensors ....................... 143 4.5.3 Linearity of CCD sensors .................... 143 4.5.4 Noise sources and types ..................... 145 4.5.5 Signal-to-noise ratio ........................ 153 4.6 Project J: extra-solar planet transits ................... 154 4.6.1 Equipment required ........................ 155 4.6.2 Conducting the observations .................. 156 4.6.3 Reducing and analyzing your data .............. 160 4.6.4 Test cases ............................... 161 4.6.5 Reporting your results ....................... 162 4.7 Photometry on the standard B-V-R system .............. 162 4.7.1 The standard B-V-R photometric system .......... 163 4.7.2 Atmospheric extinction ...................... 164 4.7.3 Transformation coef®cients ................... 168 4.7.4 Putting photometry onto the standard system........ 171 4.8 Project K: asteroid phase curves ..................... 172 4.8.1 Equipment needed ......................... 176 4.8.2 Making the observations ..................... 177 4.8.3 Reducing and analyzing your data .............. 178 4.8.4 Reporting your results ...................... 180 4.9 SASandCBA................................. 180 4.10 Resources .................................... 181 4.11 References .................................... 181 5 CCD astrometry .................................... 183 5.1 Basic principles of astrometry ....................... 185 5.1.1 Equipment needed ......................... 186 5.1.2 Making the observations ..................... 189 5.1.3 Reducing and analyzing your results ............. 189 5.2 Project L: asteroid astrometry ....................... 190 5.2.1 Finding the asteroid ........................ 191 5.2.2 Asteroid imaging routine ..................... 191 5.2.3 Special considerations for near-Earth asteroids ...... 192 5.2.4 Determining the astrometry ................... 193 5.2.5 Reporting your data ........................ 194 x Contents 5.2.6 Applying for a Minor Planet Center ``observatory code'' 194 5.3 Project M: separation and position angle of binary stars ..... 195 5.3.1 How close can you go? ...................... 197 5.3.2 Testing yourself ........................... 199 5.3.3 Selecting your target pairs .................... 200 5.3.4 Reporting your results ...................... 200 5.3.5 Other techniques .......................... 201 5.4 Resources .................................... 203 5.5 References .................................... 203 6 Discovery projects ................................... 205 6.1 Project N: lunar meteor impacts...................... 206 6.1.1 Equipment needed ......................... 208 6.1.2 Planning your observations ................... 210 6.1.3 Conducting the observations .................. 213 6.1.4 Analyzing, reducing,