Introduction to Amateur Astronomy TCAA Guide #1 Carl J. Wenning Introduction to Amateur Astronomy Copyright © 2019 Twin City Amateur Astronomers, Inc. All Rights Reserved 1 Introduction to Amateur Astronomy TCAA Guide #1 VERSION 1.6 SEPTEMBER 3, 2019 ABOUT THIS GUIDE: This Introduction to Amateur Astronomy guide – one of several such TCAA guides – was created after several years of thinking about the question of why more people don’t become amateur astronomers. This remains a mystery for most amateur astronomers and astronomy clubs, but especially for the TCAA where we have a friendly and stable organization, outstanding resources, two good observing sites, a solid web presence, a nationally-recognized award-winning newsletter, membership brochures, a good Facebook presence, regular publicity, and plenty of member education and public outreach. Despite these facts, membership in the TCAA has been roughly stable at around 40-50 members since the start of the club in 1960. Why should this be when we have a metropolitan area of over 100,000 people? There appears to be two contributing causes: (1) people no longer understand the concept of a hobby, and (2) given the recent technological advances in telescopes and imaging equipment many people are flummoxed by what they need to know to pursue amateur astronomy as a hobby. This guide has been created in response to the latter impediment. A second publication, TCAA Guide # 3 – Astronomy as a Hobby – addresses the former impediment. (http://tcaa.us/Download/Astronomy_as_a_Hobby.pdf) This guide, TCAA Guide #1, provides an introduction to the basic knowledge with which a would-be amateur astronomer should be familiar. While it is not a substitute for learning more extensively about the science of astronomy, it provides the basic information one needs to bridge the gap from neophyte to an observer vested with the knowledge of what it takes to properly view the heavens using basic equipment – eyes, binoculars, and simple telescopes. As such, this is not a reference work. It is not intended to be the answer to all questions that an amateur astronomer might have; it merely provides sufficient information to get one started in the field of amateur astronomy. Amateur astronomy is a lifetime pursuit for many of us. The author gratefully acknowledges the assistance of the following TCAA members who either provided guidance or conducted an editorial review: Tony Cellini, Dr. Allan Saaf, Ken Kashian, Jim Gibbs, and especially Geoff Hughes. ABOUT THE AUTHOR: Dr. Carl J. Wenning is a well-known Central Illinois astronomy educator. He started off viewing the heavens with the aid of his grandfather in the summer of 1957. Since that time, he continued viewing the night sky for nearly six decades. He holds a B.S. degree in Astronomy from The Ohio State University, an M.A.T. degree in Planetarium Education from Michigan State University, and an Ed.D. degree in Curriculum & Instruction with a specialization in physics teaching from Illinois State University. Dr. Wenning was planetarium director at Illinois State University from 1978 to 2001. From 1994-2008 he worked as a physics teacher educator. Retiring in 2008, he continues to teach physics and physics education courses. He also taught astronomy and physics lab science almost continuously at Illinois Wesleyan University from 1982 to 1999. He has over 40 years of university- level teaching experience. Carl became associated with the TCAA in September 1978 – shortly after he was hired to work at Illinois State University. Today he is an Astronomical League Master Observer (having completed 14 observing programs to date) and received the 2007 NCRAL Region Award for his contributions to amateur astronomy. He is a lifelong honorary member of the TCAA and is a member of its G. Weldon Schuette Society of Outstanding Amateur Astronomers. He is currently chairman of the North Central Region of the Astronomical League (2017-2021) which includes Illinois, Iowa, Wisconsin, Minnesota, North and South Dakota, and the Upper Peninsula of Michigan. 2 Introduction to Amateur Astronomy Copyright © 2019 Twin City Amateur Astronomers, Inc. All Rights Reserved TABLE OF CONTENTS PREFACE: WHAT IT TAKES TO BECOME AN AMATEUR ASTRONOMER…………………………………………...…………………………..……….…………….PG. 5 INTRODUCTORY TOPICS: 1. MOTIONS OF THE STARS…………………………………………..…………………………..…………………………..……………………….……….….PG. 7 2. SEASONAL SKY MAPS AND CONSTELLATIONS……………..…………………………..…………………………..……………………………………....PG. 9 3. THE PLANISPHERE – AN ANALOG COMPUTER………………………………………………………………………………………….……………………PG. 9 4. OBSERVING APPLICATIONS FOR COMPUTERS, CELL PHONES, AND TABLETS……………………………………..……………………………….….PG. 9 5. HOW TO FIND NORTH IN THE SKY…………………………..…………………………..…………………………..…………………………………......PG. 11 6. MAGNITUDES……………………………………………………………………………………………………………………………………………………. PG. 11 7. MOTIONS OF THE SUN…………………………..…………………………..…………………………..…………………………………………….….…..PG. 12 8. MOTIONS AND PHASES OF THE MOON…………………………..…………………………..…………………………..…………………………….….PG. 12 9. ANGULAR MEASURES IN THE SKY…………………………..…………………………..…………………………..…………………………………......PG. 13 10. THE CELESTIAL SPHERE…………………………..…………………………..…………………………..…………………………………………………...PG. 13 11. ALTITUDE AND AZIMUTH…………………………..…………………………..…………………………..………………………………………….….....PG. 14 12. RIGHT ASCENSION AND DECLINATION…………………………..…………………………..……………..………………..…………………….…..….PG. 14 13. TELESCOPES VERSUS BINOCULARS…………………………..…………………………..…………………………………………………………….......PG. 15 14. USING BINOCULARS……………………………………………………………………………………………………………………..…………….……….PG. 16 15. HOW TELESCOPES WORK……………………….…..…………………………..…………………………..…………………………………….……......PG. 16 16. THREE POWERS OF A TELESCOPE…………………………..…….……………………..…………………………..………………………………....…..PG. 17 17. LIMITING MAGNITUDE OF A TELESCOPE……………………………………………………………………………………………….…………….……..PG. 18 18. COMMON TELESCOPE TYPES…………………………..…………………………..…………………………..…………………………………….….…..PG. 21 19. COMMON TELESCOPE TRAITS…………………………..…………………………..…………………………..………………………………….………..PG. 23 20. TELESCOPE MOUNTS AND PIERS…………………………..…………………………..…………………………..…………………………….……..…..PG. 25 21. HOW TO BUY A TELESCOPE…………………………..…………………………..…………………………..……………………………………………..PG. 26 22. TELESCOPE EYEPIECE BASICS…………………………..…………………………..…………………………..……………………………………..……..PG. 27 23. EYEPIECE FIELD ORIENTATION…………………………..…………………………..…………………………..…………………………………..……..PG. 29 24. FINDER SCOPES…………………………..…………………………..…………………………..………………………………………………..…………..PG. 29 25. STAR HOPPING…………………………..…………………………..…………………………..……………………………………………………………..PG. 31 26. SKY DARKNESS, TRANSPARENCY, AND SEEING………………….…………..…………………………..……………………………….….…..……..PG. 32 27. DARK ADAPTATION…………………………..…………………………..…………………………..………………………………………………..……..PG. 34 28. THE ART OF ASTRONOMICAL OBSERVING…………………………..…………………………..…………………………..…………………………...PG. 34 29. OPTIMIZING OBSERVATIONS OF DEEP SPACE OBJECTS…………………………………………………………………………………………….……PG. 37 30. THE USE OF OBSERVING FILTERS…………………………………………………………………………………………………………………….……….PG. 41 31. RECORDING YOUR OBSERVATIONS…………………………..…………………………..…………………………..…………………….………….…..PG. 42 32. MOON PHASES AND THEIR EFFECT ON OBSERVING…………………………..…………………………..………………..…………………………..PG. 43 33. MOON PHASE VERSUS BRIGHTNESS………………………………………………………………………………………………………..……………….PG. 44 34. DEALING WITH WEATHER…………………………..…………………………..…………………………..………………………………………………..PG. 45 35. CELESTIAL OBJECTS TO OBSERVE…………………….……..……………………………..…………………………..…………………………….……..PG. 47 36. ASTRONOMICAL LEAGUE OBSERVING PROGRAMS…....…………………………..…………………………..…..…………………………..………PG. 48 Introduction to Amateur Astronomy Copyright © 2019 Twin City Amateur Astronomers, Inc. All Rights Reserved 3 ADVANCED TOPICS: 37. CLEANING YOUR OPTICS…………………………………………………………………………………………………………………………………….…PG. 49 38. CHECKING THE COLLIMATION OF YOUR TELESCOPE………………………………………………………………………………………………………PG. 50 39. CHECKING YOUR OBJECTIVE’S OPTICS………………………………………………………………………………………………………….………..…PG. 50 40. BALANCING YOUR TELESCOPE…………………………..……………………………………………..…………………………………………..………..PG. 52 41. POLAR ALIGNING AN EQUATORIAL MOUNT………………………..…………………………..………………………………………………………..PG. 53 SUGAR GROVE OBSERVATORY: 42. OPERATING THE 10’ ASH DOME……………………………………………………………………………..………………………..……………………PG. 55 43. OPERATING SGO’S CELESTRON CPC 11” TELESCOPE……………………………………………………………………..……………..….………. PG. 56 44. PERSONAL, OBSERVATORY, AND SGNC SAFETY….........................................................................................................PG. 57 45. RESERVING SGO FOR AN OBSERVING SESSION………………………………………………………………………………………………….……… PG. 58 4 Introduction to Amateur Astronomy Copyright © 2019 Twin City Amateur Astronomers, Inc. All Rights Reserved PREFACE: WHAT IT TAKES TO BECOME AN AMATEUR ASTRONOMER Since the founding of the TCAA in 1960, amateur astronomy has changed dramatically. At that time, the norm in amateur astronomy was a 2.4” refractor or a 4.25” reflector. When telescopes were turned to the heavens, objects viewed consisted of bright solar system bodies, double stars, and few of the brighter nebulas, clusters, and galaxies. Since that time, there has been a tremendous growth in the size of available equipment and the number of accessories has expanded dramatically. Amateur astronomy today is much akin to professional astronomy of just a decade or so ago. As a result, it’s much harder to bridge the gap from non-astronomer to amateur astronomer today. Thinking about this topic for a while, I have concluded that the following are things that people need to know and be able to do in order to wear the