Last updated: 4 October 2007
Real Astronomy with Small Telescopes
by Michael K. Gainer
This Springer "Practical Astronomy Series" book is targeted at 80mm refractors and 90mm Maksutovs (which includes the ETX-80 and ETX-90). The techniques described for doing some real astronomy are also applicable to larger telescopes as well. Many of the techniques combine a digital (or film) camera with a fixed lens with the telescope (although any camera/imager could perform the same functions if you already have one). The emphasis of the book is "on what you can do with a small telescope rather than only on what you can see."
The book's Table of Contents includes:
Computer Hardware and Software
1. The Celestial Sphere
2. The Measurement of Time
3. The Equatorial Telescope Mount
4. Telescope Considerations
5. Astronomical Photography
6. The Sun
7. The Moon
8. The Planets
9. Comets and Asteroids
10. Visual Binary Stars
11. A Binary Star True Orbit Projector
12. Visual Observations of Variable Stars
13. Photography of Variable Stars
14. Star Clusters and Nebulae
15. A Color-Magnitude Diagram for The Pleiades
16. The Design of an Objective Prism Spectrograph
17. The Proper Motion of Barnard's Star
References and Additional Reading
Generally, five to ten pages per chapter are used to introduce and discuss techniques to be used. The computer software discussed is for Windows only. Macintosh users have alternative applications (unmentioned) that can perform the same functions. The "projects" discussed include measuring sizes, motions, colors, and more. The first five chapters establish the foundation for the remainder of the book. The remainder of the chapters discuss "projects" that you can do for specific purposes for specific types of objects. If the mechanics or physics of objects in the sky interest you, you will likely find one or more of the projects intriguing. And none are particularly difficult or require exotic equipment or math.
In Chapter 3, The Equatorial Telescope Mount, the author somewhat dismisses the GOTO systems available for small telescopes, pointing out that you could spend the same money on some worthwhile accessories. While it is true that small telescope GOTO systems are a relatively recent capability and are not needed, GOTO telescopes can be used to do "real astronomy". Afterall, professional astronomers use GOTO telescopes today for doing "real astronomy". So if you have a GOTO telescope, use it for the projects discussed in the book. If you don't already have a GOTO telescope and are willing to learn how to navigate around the night sky just like astronomers have done for centuries, then the advice of saving some money to spend on accessories should be seriously considered. [The author says he started the book a number of years ago and would be less negative about GOTO telescopes today.]
Chapter 5 mentions "Scopetronics" (really "ScopeTronix"). Readers are urged to currently use Scopetronix with caution. The company is apparently experiencing some difficulties as it tries to rebuild its reputation as a quality supplier of quality products. Hopefully this stage will pass soon and I can once again strongly recommend Scopetronix.
In Chapter 7, The Moon, there is a discussion of how to measure the Moon's diameter on page 53. It says to measure the diameters of craters "near the terminator". However, if the terminator is not near the center of the Moon's disk as seen from the Earth the craters will be "foreshortened" and so the measurements will be in error unless measured in a North-South direction. The book does not mention this error condition.
The book contains many useful templates for measuring angles and dimensions of various objects. It is expected that the user will scan these into their computer. Unfortunately, since the book can not be opened to be completely flat, the scans may contain errors due to the page not being flat on the scanner's glass plate. It would be nice if these templates were available online for download, although as the author points out, they can still be scanned without distortion.
The author supplied this additional information, which I agree with:
There two particular chapters which I wish to recommend to you. The method I have developed for measuring binary stars makes it possible to measure binaries with 2" to 5" separations to 0.1" accuracy. The conventional wisdom is that 90 mm Mak is only useful for observing the colors of the components and testing telescope resolution. Their are a number of binaries with separations in that range which have undetermined or poorly determined orbits. Some of these are listed in the book and make a very worthwhile project for ETX owners.
The method for measuring variable star which I have introduced is an updated version of the "fly spanker" used in the early photographic studies of variables. The values I obtain for long period variables are always within 0.1 magnitude of the mean values for visual magnitudes reported in the AAVSO Quick Look file for a particular date. It eliminates a lot of the guess work of direct visual observation. By converting the photos to black and white it eliminates the effect of the redness of long period variables on direct visual measurements. This type of observation would be a good activity for ETX 80 owners.
This book contains many excellent projects that you can do with almost any small or large telescope. Not all these projects will appeal to everyone but if you want to do some "real astronomy" with your ETX (or other telescope) you will find many exciting and worthwhile and sometimes challenging projects in the book. Some projects can be done on one night, some over a period of days, weeks, or months, and some over one or more years. You can even report your results to various organizations using information supplied in the book. So, if you are ready to take on new challenges and opportunities with your telescope, check out this book. Have fun and enjoy!
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