The Star Atlas Companion by Philip M. Bagnall

Rating: 9/10

The Star Atlas Companion is a necessary addition to every amateur astronomer who is interested in how the stars and star clusters one might observe with a small to medium telescope would actually appear.

In a regular star atlas one might expect to find star charts that are helpful for locating specific stars or other objects of interest.

In the Star Atlas Companion you’ll first find out about the history of the constellation, whether or not it was already known in ancient times or was later added by some astronomer in 17th or 18th century or even later.

Then you find out about the named stars, what the name means, about the stars’ physical characteristics and if there’s something interesting connected to the star – maybe it’s a variable star – one of the Cepheid or Mira type variables perhaps? or maybe it was the first ever star to have been observed in daylight like in the case of Arcturus in the beginning of 17th century in France.

Some of the most important parts that aren’t found in many other books are the size comparisons - you find out how large or small the stars are in comparison to the Sun, how far away they are, and how the constellation would appear if they’d all be 15 parsecs away. You also see an approximation to how the constellation would appear in the night sky with different magnitude stars represented differently.

The book also gives some information about star clusters and how they would look through a telescope – it’s one thing to be able to point a telescope at the right location, but there might be difficulties trying to identify it – is it really this open cluster you’re looking for? The images in this book will certainly be helpful in such cases.

In general this book is helpful for planning your observations and finding out more about the stars and constellations and would be helpful in illustrating how big and far apart stars really are.

It contains a lot of information, possibly more than some of the smart computerized guidance systems that some telescopes have.

Labels: book review, Philip M. Bagnall, The Star Atlas Companion