Too much, or two little?

I've written about Stephen James O'Meara's other fine stargazing books, but have managed to overlook his 2007 publication on the Herschel 400. Interestingly, he is listed on the title as "Steve"; I don't know if this is an attempt to make him seem less formal, and therefore the book seem more accessible, or what.

Stephen has published three other sizable books covering largely the best-of-the-best: deep-sky objects that can be detected with small aperture, and therefore are showpieces in large aperture: he is kind of the "evil twin" of Alvin Huey, who dwells on the impossible, nor nearly impossible objects. Perhaps I have two role reversed...

In fact, the two have similarities: expert viewers who through both discipline and good eyesight can see much more than I. Both write extensively about how to see more. O'Meara is more of the poet, one who speaks to a broader audience.

The Herschel 400 is a list derived from objects logged by the Herschels, selected to be visible in smaller scopes, six-inches, and in moderately light polluted areas. There is, as a result, overlap with other lists: think of it as being like the Messier and Caldwell lists, but which goes a little deeper. It is a very fine list, indeed, a good one to pull out for those tired of the more common lists. I believe I've seen all 400, but it would be too much work to correlate against my own notes.

O'Meara takes a little different approach from his earlier books. He doesn't provide a hand drawing of each object, rather a nice quality DSS image, descriptions, his visual impressions using his 4" Genesis refractor, and his own star charts. He has organized the objects by a suggested viewing month and collected them into a plan to view across multiple nights. This organization the book both a valuable planning tool and reference. It would have been nice to have it cross-indexed with the most popular star charts, such as Sky & Telescopes Pocket Sky Atlas, at the very least. Furthermore, a big, heavy book like this really doesn't lend itself to field use. Wouldn't it be nice to have a loose-leaf version of this, so you could pull out the sections you were going to use?

I wonder if O'Meara has set unrealistic expectations over what a 4" refractor can see. He argues that since he is viewing in non-polluted areas, 4" is enough. It is for him, but he is the exception. I have owned two 4" refractors over the years and come to the conclusion that 4" is either too much, or too little. A 4" scope really isn't enough aperture to serve deep-sky objects well: 5" or 6" would be significantly better. Unfortunately, a 4" scope barely qualifies as "portable," although it is significantly more portable than the larger refractors. This is an important discussion, because it seems that middle-aged men are drawn to the idea of a 4" refractor and I fear that many end up essentially in closets because they are too much trouble for what you are going to see.

I've come to the conclusion that if you want "portable," 90 mm, or about 3½", is really portable. It gives you about 80% of the light gathering, the tube is about 80% of length, and the tube is going to weight about 60% of a 4" (your mileage will obviously vary...) In fact, I have abandoned my 102 mm Takahashi for a 90 mm StellarVue. Although I don't have the ability to do a side-by-side comparison, the smaller scope is much easier to quickly whip out for a brief session and I don't really notice a difference in what or how much I can see. Either way, such small apertures may allow you to detect a deep-sky object, but you aren't going to see much. If you really want to see something, get a bigger scope!

This is not to say that O'Meara doesn't teach us very important lessons: how to see as much as possible with a little discipline and – most importantly – how to pick out the best jewels from an overloaded treasure trove.