User manual MEADE LX-90-LNT

[. . . ] Instruction Manual 8" LX90 Schmidt-Cassegrain Telescope AutoStar® -- LNTTM -- SmartFinderTM The Meade Schmidt-Cassegrain Optical System (2) (1) Ray (2) Ray (1) (2) (1) Focal Plane Secondary Mirror Primary Baffle Tube Field Stops Primary Mirror Correcting Plate Secondary Baffle (1) (2) In the Schmidt-Cassegrain design of the Meade LX90, light enters from the right, passes through a thin lens with 2-sided aspheric correction ("correcting plate"), proceeds to a spherical primary mirror, and then to a convex secondary mirror. The convex secondary mirror multiplies the effective focal length of the primary mirror and results in a focus at the focal plane, with light passing through a central perforation in the primary mirror. The Meade 8" LX90 Schmidt-Cassegrain includes an oversize primary mirror of an 8. 25" diameter, yielding a fully illuminated field-of-view significantly wider than is possible with a standard-size primary mirror. Note that light ray (2) in the figure would be lost entirely, except for the oversize primary. [. . . ] Press ENTER when the country/state you wish to add displays. Press ENTER when the city you wish to select displays. The sites you choose will appear at the top of the Select list (all other available sites will be listed after the sites you have chosen). To choose a site, navigate to "Site: Select. " Press ENTER. Both Zip Codes and Cities are displayed. When the desired zip code or site displays, press ENTER. 6. To Edit a Site: In this procedure, you will enter a location that is not available in the AutoStar database by editing data of a nearby site. You will edit the location's name, latitude, longitude and the time zone shift. You will then select the site to enable it. You will need to know the latitude and longitude of your location to perform this procedure. This information is available on most maps. Using the Add option, choose a site on the list that is closest to your observing site and press ENTER so that the site is added to your observing sites list. Choosing a site already on the list (as opposed to using the "Custom" feature) makes it easier to edit, as the "Time Zone" value may not need to be changed. Scroll to "Site: Edit" and press ENTER. The name of the site you have just entered to your list displays; if it does not, scroll to the site. 2. 3. LX90 TIPS Join an Astronomy Club, Attend a Star Party One of the best ways to increase your knowledge of astronomy is to join an astronomy club. Check your local newspaper, school, library or telescope dealer/store to find out if there's a club in your area. At club meetings, you will meet other astronomy enthusiasts with whom you will be able to share your discoveries. Clubs are an excellent way to learn more about observing the sky, to find out where the best observing sites are and to compare notes about telescopes, eyepieces, filters, tripods and so forth. Often, club members are excellent astrophotographers. Not only will you be able to see examples of their art, but you may even be able to pick up some "tricks of the trade" to try out with your LX90 telescope. See page 39 for more information about photography with the LX90. Many groups also hold regularly scheduled Star Parties at which you can check out and observe with many different telescopes and other pieces of astronomical equipment. [. . . ] Open Clusters are loose groupings of young stars, all recently formed from the same diffuse nebula. The Pleiades is an open cluster 410 light years away (Fig. Through the LX90, numerous stars are visible. Constellations are large, imaginary patterns of stars believed by ancient civilizations to be the celestial equivalent of objects, animals, people, or gods. [. . . ]