Book contents
- Frontmatter
- Contents
- List of Illustrations
- Preface
- Acknowledgements
- 1 History and development of the 20-cm Schmidt–Cassegrain
- 2 First observation – the Moon
- 3 Planets, double stars and other bright things
- 4 Deep sky
- 5 A Couple of Interesting Problems
- 6 Some accessories for the telescope
- 7 Observing with friends
- 8 Projects
- 9 Photography
- 10 Photometers, computers, image intensifiers and television
- 11 Afterword
- Appendix 1 Sources of further information
- Appendix 2 How to align the polar axis with the Earth's axis of rotation
- Appendix 3 Collimation of an S–C telescope
- Appendix 4 Cleaning the corrector plate
- Appendix 5 Mount vibrations
- Appendix 6 Field operations packing checklist
- Appendix 7 Astronomical nomenclature
- Appendix 8 Catalogue of bright stars & interesting things
- Appendix 9 Catalogue of nearby stars
- Appendix 10 Messier Catalogue
- Index
2 - First observation – the Moon
Published online by Cambridge University Press: 05 August 2012
- Frontmatter
- Contents
- List of Illustrations
- Preface
- Acknowledgements
- 1 History and development of the 20-cm Schmidt–Cassegrain
- 2 First observation – the Moon
- 3 Planets, double stars and other bright things
- 4 Deep sky
- 5 A Couple of Interesting Problems
- 6 Some accessories for the telescope
- 7 Observing with friends
- 8 Projects
- 9 Photography
- 10 Photometers, computers, image intensifiers and television
- 11 Afterword
- Appendix 1 Sources of further information
- Appendix 2 How to align the polar axis with the Earth's axis of rotation
- Appendix 3 Collimation of an S–C telescope
- Appendix 4 Cleaning the corrector plate
- Appendix 5 Mount vibrations
- Appendix 6 Field operations packing checklist
- Appendix 7 Astronomical nomenclature
- Appendix 8 Catalogue of bright stars & interesting things
- Appendix 9 Catalogue of nearby stars
- Appendix 10 Messier Catalogue
- Index
Summary
Before you set up your telescope you might ask where the Moon is. After a few months of observing you'll have a sense of where the Moon is just as you know, at any time, roughly where the Sun is in your sky. For now, you may have to look it up in one of the popular astronomy magazines. Most newspapers also list the times of Sunrise, Sunset, Moonrise and Moonset in the section with local weather predictions.
Select a site for your telescope which doesn't have trees or streetlamps in the way. After reading your telescope manual, set up the telescope. Now you must align the polar axis to the Pole Star. There are many methods for accomplishing this and your telescope manual probably describes at least one. Another method is described in Appendix 2. Don't let anybody tell you that there is only one ‘proper’ procedure for polar alignment. The varying procedures differ in accuracy of alignment and time to accomplish.
If you are going to casually visually observe the Moon and bright planets then you don't need to have the polar axis aligned any closer than about three to five degrees. If you are going to look for faint galaxies and nebulae, especially ones which you've never seen before then you need an accuracy of about one degree. This is crucial if you intend to use the setting circles on your mount.
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- Information
- The 20-cm Schmidt-Cassegrain TelescopeA Practical Observing Guide, pp. 8 - 32Publisher: Cambridge University PressPrint publication year: 1994