User manual MEADE LX-90

[. . . ] Instruction Manual 8" LX90 Schmidt-Cassegrain Telescope with Autostar Hand Controller Meade Instruments Corporation 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. [. . . ] Perform these procedures using the Site options (Add, Select, Delete, Edit) of the Setup menu. To Add a Site to the user-defined site list: In this example, you will choose a city and add it to the database list. Press ENTER, Scroll through the options until "Site: Add" displays. You may add 5 sites using this method (the sixth site is the site you added during the Initialization process) To choose a site, navigate to "Setup: Select. " Press ENTER. When the desired site displays, press ENTER. 5. 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 need to know the latitude and longitude of your location to perform this procedure. 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. The name of the site you have just entered to your list displays; if it does not, scroll to the site. Using the Arrow keys, change the name of the site so that it now reads the name of your observing location. "Edit: Name" displays again. LX90 TIPS Look into the Future The Autostar Date option in the Setup menu is much more than just an entry of today's date; with it you can look far into the future or learn about past events. Autostar can calculate the date and times of future events and, except for eclipses, past events as well (based on the current calendar system). To use this feature, enter the desired date in the Setup menu and select an option in the Event menu. Autostar can calculate dates and times for Sunrises, Sunsets, Moonrises, Moonsets, Moonphases, Solar and Lunar Eclipses (for the next 100 years), meteor showers, equinoxes and solstices, and the minimums of Algol. One very practical use of the date menu is to check the Sunset option to determine when you can begin your astronomical observing. 2. 3. 4. 29 Time Zone Atlantic Eastern Central Mountain Pacific Hawaii Shift -4 Hours -5 Hours -6 Hours -7 Hours -8 Hours -10 Hours 5. 9. Press the Scroll Down key and "Edit: Latitude" displays. Using the Number Keys, enter the latitude of your observing site and then press ENTER. Using the Number Keys, enter the longitude of your observing site and then press ENTER. (If the site you chose from the list in step 1 has the same Time Zone as the site you are editing, just press ENTER again to go on to the next step. ) "Time Zone" refers to the Greenwich Time Zone shift. Users West of Greenwich, use "-" hours (one hour per time zone) and users East of Greenwich use "+" hours. For the United States, look up the shift in Table 1. Table 1: Time Zone Shift. 10. [. . . ] First, find the Big Dipper which is part of the constellation Ursa Major. Extending directly out from the far side of the Big Dipper's cup is the constellation Orion. One of the most exquisite areas of the winter sky, Orion is distinguished by Orion's belt, which is marked by three stars in a row. The Orion Nebula is located South of the belt and is one of the most observed deep-sky objects by amateur astronomers. [. . . ]