Why a CAT?

Abstract

If you have even the slightest interest in the fascinating world of telescopes and astronomy, you have probably seen one of those short, stubby and wonderfully high- tech looking Schmidt-Cassegrain telescopes (SCTs). If, as a new amateur astronomer, you’ve been reading the astronomy magazines — Astronomy Now, Sky and Telescope, or Astronomy — you have no doubt been mightily impressed by the many full-page, full-color advertisements the SCT manufacturers run in every issue. Reading the enthusiastic ad copy, you’d think the Schmidt-Cassegrain is the only telescope worthy of your consideration. This may or may not be true, but putting aside advertising hyperbole, the SCT may well be the best and most versatile telescope for the average amateur astronomer. As we’ll see, SCTs do have weaknesses as well as strengths, but the fact that these portable observatories have claimed a very large share of the telescope market over the last 25 years makes it obvious that there’s something good going on here. Advertising copy alone wouldn’t account for the astounding continuing popularity of these instruments.