I'm a math undergrad, but I'm really interested in learning positional astronomy; However, the only well-referenced textbook I've come up with is Spherical Astronomy by W. M. Smart.

I would like to understand how suitable it is today. I have the 6th edition which seems to be the latest, but which was issued back in 1977. I know that a relatively old math text book, for example Apostol's Calculus (published in the 60's, if I'm not wrong), won't present too much trouble, but I'm a newcomer to astronomy, so I don't know if a book printed in 1977 is "up to date".

Given the case that there are better or more up-to-date books, are there other recommended texts for me to read as well or is this one a good choice?

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    $\begingroup$ Do you mean Spherical Astronomy by W.M. Smart (from this comment) or are you talking about a different book? Or perhaps Positional Astronomy by D. McNally? $\endgroup$
    – uhoh
    Commented Nov 8, 2018 at 5:58
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    $\begingroup$ Exactly, but that seems to be the fourth edition, I have the sixth one. That's the only detail. $\endgroup$ Commented Nov 8, 2018 at 6:02
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    $\begingroup$ Spherical trig has not changed since 1977. $\endgroup$
    – ProfRob
    Commented Nov 8, 2018 at 9:57
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    $\begingroup$ There is another book called Spherical Astronomy, by Robin M Green. Green updated Smart's book (the 6th edition, 1977) and then wrote his own text. I haven't read it, but it appears more modern in style, although as noted above the subject hasn't changed 1977, albeit the ready availability of computational power has made life easier. $\endgroup$
    – Dr Chuck
    Commented Nov 8, 2018 at 11:15
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    $\begingroup$ If you want to make positional calculations, you would implement the algorithms that you learn from the book, but not use any positional information from them. You would get your positional information out of a star catalog (if you are doing stars), or get the latest ephemerides from JPL. $\endgroup$
    – Dave
    Commented Nov 8, 2018 at 18:30

1 Answer 1


The short answer is "no". The IAU has formalized standards for positional astronomy far beyond what's in this book. The only definitive book I'm aware of on the new processes is "The Explanatory Supplement to the Astronomical Almanac". Spherical Trigonometry really isn't used in the new processes, so this book is only useful from a historical perspective, or if you just want to compute the position of something and aren't too particular that it matches modern software to the microarcsecond level.


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