Orion XT12 Optional IntelliScope Computerized Object Locator, Stars, Deep-Sky Objects

the sky, excluding the Sun and the Moon. It is so bright that sometimes it is visible to the naked eye during full daylight! Ironically, Venus appears as a thin crescent, not a full disk, when at its peak brightness. Because it is so close to the Sun, it never wanders too far from the morning or evening horizon. No surface markings can be seen on Venus, which is always shrouded in dense clouds.

MARS The Red Planet makes a close approach to Earth every two years. Observing Mars is most favorable at these times. You should see a salmon-colored disk with some dis- tinct dark patches, and you may be able to spot a whitish polar ice cap. To see surface detail on Mars, you will need a high power eyepiece and very steady air!

D. The Stars

Stars will appear as tiny points of light. Even powerful tele- scopes cannot magnify stars to appear as anything more than pinpoints. You can, however, enjoy the different colors of the stars and locate many pretty double and multiple stars. The famous “Double-Double” in the constellation Lyra and the gor- geous two-color double star Albireo in Cygnus are favorites. Defocusing a star slightly can help bring out its color.

E. Deep-Sky Objects

Under dark skies, you can observe a wealth of fascinating deep-sky objects; that is, objects that reside outside of our solar system. These include gaseous nebulas, open and globular star clusters, and a variety of different types of galax- ies. The large aperture of the SkyQuest XT12 IntelliScope is particularly well suited to gathering light, which is critical for observing these usually faint celestial entities. For deep-sky observing it is important that you find an observing site well away from light pollution. Take plenty of time to let your eyes adjust to the darkness. As you become more experienced and your observing skills get sharper, you will be able to ferret out more and more subtle details and structure from these fascinating objects.

Beginners are often surprised to discover that the deep- sky objects they see through the eyepiece of a telescope are mostly grayish, not colorful like those you see in long- exposure photographs. The reason is that our eyes are not sensitive to color in faint light. Still, there is something very special about seeing an astronomical object in real time with your own eyes — “live,” if not in living color.

Note About Astrophotography

The SkyQuest XT12 IntelliScope is designed for visual, not photographic use. The Dobsonian mount is not an equatorial- type mount, so it cannot be motor driven for long exposure astrophotography. The telescope has also been optically optimized for visual use, since photographic optimization degrades visual performance.

With that in mind, however, it is possible to do some simple astrophotography with a SkyQuest XT12 IntelliScope. With the use of afocal photography techniques (where the camera is simply put right up to the eyepiece to take a picture) and digital cameras, it is possible to take pictures of bright objects.

Certain photograph aids, such as the Orion SteadyPix, can help in taking photos by the afocal method.

6.Optional IntelliScope Computerized Object Locator

Perhaps the most exciting feature of the SkyQuest XT12 IntelliScope is its compatibility with the optional IntelliScope Computerized Object Locator (controller). When plugged into the IntelliScope port on the telescope’s base, the IntelliScope controller enables the user to point the telescope quickly and effortlessly to more than 14,000 celestial objects with the push of a button. After a simple two-star alignment procedure, you just select an object to view from the intuitive keypad, then read the guide arrows on the controller’s illuminated liquid crystal display and move the telescope in the corresponding direction. In seconds, the object will be waiting in the tele- scope’s field of view, ready to observe. It’s that simple!

Even without the optional IntelliScope controller, the SkyQuest XT12 IntelliScope provides a tremendous observing experi- ence. But addition of the controller provides a whole new level of convenience and capability, as you’re able to locate and view more objects in an evening that you ever could before.

The IntelliScope controller works by communicating elec- tronically with a pair of high-resolution, 9,216-step digital encoders, one of which will reside on one of the telescope’s side bearings (this encoder is included with the optional IntelliScope controller), the other of which you installed dur- ing assembly of the base. The encoders allow highly precise positioning of the telescope to coordinates programmed into the IntelliScope controller’s database for each object. Since the telescope is not dependent on motors for movement, you can point the telescope at your target much more quickly (and quietly!) than other computerized telescopes can — and with- out guzzling all those batteries in the process.

The IntelliScope database includes:

•7,840 objects from the Revised New General Catalog

•5,386 objects from the Index Catalog

•110 objects from the Messier Catalog

•837 selected stars (mostly double, multiple, and variable stars)

•8 planets

•99 user-programmable objects

With the user-friendly IntelliScope controller, there are many ways to locate an object. If you know its catalog num- ber (NGC or Messier number, for instance), you can enter it using the illuminated keypad buttons. Or you can press one of the object-category buttons (Cluster, Nebula, Galaxy, etc.) to access a list of objects by type. For a tour of the best objects visible in a given month, you just press the Tour but- ton. Another great feature of the IntelliScope is the ability to identify an “unknown” object in the field of view — just press

18