Illuminated Reticle Eyepieces

Celestron Micro Guide Reticle

There are now readily available a number of proprietary eyepieces which are supplied by their manufacturers with illuminated reticle systems. They have completely transformed amateur double-star astrome-try.2 The Celestron Micro Guide eyepiece provides a typical example, but other makes are essentially similar this section refers specifically to the Celestron version . Reticle eyepieces of this type require the use of a motor-driven equatorial mount, with remote slow-motion controls to both...

History of Double Star Observation

In 1610 the invention of the telescope by Galileo gradually led to the discovery of telescopic double stars but these were noted merely by the way. In 1617 Castelli found that Mizar was itself double4 and he later added a few more pairs. In 1664 Robert Hooke was observing the comet discovered by Hevelius when he came across Y Arietis, a pair of pure-white stars of 4th magnitude separated by some 8''. Over the next hundred years or so a few more double stars were noted but not catalogued in any...