Celestron CGE Pro 11 Inch Schmidt-Cassegrain Telescope – 11087 Celestron

The Celestron CGE Pro 1100 Schmidt-Cassegrain Telescope is part of Celestron’s “Top-of-the-Line” German Equatorial mounted astronomical telescopes. With the optical tube assembly of the CGE Pro 1100 weighing only 27.5 lb., this telescope is still portable enough to be taken to dark skies, and it has 89% more light gathering power than an 8″ telescope and more than 40% more than the 9.25″.  This telescope is especially at home as a solid platform for long exposure photography with optional CCD cameras or photographic equipment; it is a serious scientific research tool that comes with Celestron’s premium StarBright XLT coatings.

For astrophotography, the German Equatorial mount offers easier balancing, unlimited space at the rear of the telescope tube to mount a camera, and whole sky access. Now you can enjoy all of the NexStar software and database features with the extra stability and portability of a German Equatorial mount.

In addition to being fully computerized with a database of over 40,000 celestial objects, the CGE Pro German Equatorial mount has been completely redesigned to offer numerous design advantages:

Increased Payload Capacity – With a maximum payload of 90lbs the CGE Pro mount is able to hold the 9.25″ telescope more securely even when fully loaded with all your imaging gear.
 
All-Star Polar Alignment – Choose any bright alignment star for a software assisted alignment of the mounts polar axis that will have you ready for imaging even if you can’t see the North Star.
 
No-Tool polar alignment – Larger hand knobs for both Altitude and Azimuth adjustments.
 
Meridian Tracking – Extended tracking pass the Meridian of up to 20 degrees of uninterrupted imaging through the best part of the sky.
 
Faster slew speed – Improved gearing and motors provide faster slew speeds than ever before with a maximum slew rate of over 5°/per second.

Portability – Set up and transportation of the CGE Pro telescopes is made easy by separating the mount into smaller, easy-to-carry components. Unlike fork arm mounted telescopes, the CGE’s optical tubes can be quickly removed from their mounts making even the CGE Pro1400 easily assembled in minutes.
 
Stability – Recognized for superior stability, German Equatorial mounts place the center of gravity directly over the tripod legs and can be easily polar aligned without the use of an optional equatorial wedge. This proven design reduces the “tuning fork” vibration that can be associated with undersized fork mounts. An improved Super HD Tripod supports the CGE Pro mount. This fully extendable tripod is made from the finest 2.75″ stainless steel and can be raised to a height of 55″. The tripod uses a dual leg support for maximum rigidity with an upper leg brace to provide an outward preload and a lower leg brace providing inward tension.
 
Balance – CGE Pro equatorial mounts can easily be balanced in both axes. Simply sliding the counterweight for Right Ascension and moving the optical tube along its dovetail mounting for Declination accomplish balancing the weight of camera equipment and other visual accessories. This means that no additional weight needs to be added to balance the telescope when additional accessories are added. Clearance – CGE Pro mounts support their tubes at a single contact point allowing the tube to move freely around its polar axis without making contact with the telescope’s mount. Software features allow the user to set the mounts slew limits to guaranty safe motion. This is particularly useful when adding photographic and CCD instruments that extend from the rear of the telescopes.
 
Clearance – CGE Pro mounts support their tubes at a single contact point allowing the tube to move freely around its polar axis without making contact with the telescope’s mount. Software features allow the user to set the mounts slew limits to guaranty safe motion.  This is particularly useful when adding photographic and CCD instruments that extend from the rear of the telescopes.

FEATURES

• 9.25″ Schmidt-Cassegrain telescope
• Celestron premium StarBright XLT coatings
• CGE PRO computerized Equatorial mount
• Schmidt-Cassegrain mechanism that moves the primary mirror to adjust focus is supported by two pre-loaded ball bearings, minimizing the “mirror flop” typical of bushing focus mechanisms
• Heavy duty stainless steel tripod adjustable from 38 – 55″
• 6×30 finderscope to help accurately find objects
• Star diagonal provides more comfortable viewing position when observing objects that are high in the sky
• Proven NexStar computer control technology
• 40,000 object database with 400 user-definable objects and expanded information on over 200 objects
• New All-Star Polar Alignment routine for both Northern and Southern Hemispheres.
• Software Features include Database Filter Limits, Hibernate, five alignment methods and user-defined slew limits.
• Flash upgradeable hand control software and motor control units for downloading product updates over the Internet
• Double line, 16-character Liquid Crystal Display Hand Control with backlit LED buttons for easy operation of goto features
• Custom database lists all the most famous deep-sky objects by name and catalog number; the most beautiful double, triple and quadruple stars; variable star; solar systems; objects and asterisms
• 12VDC Servo Motors with integrated optical encoders
• Permanent programmable periodic error correction (PEC) – corrects for periodic tracking errors inherent to all worm drives
• Drive Motors – High-quality motors with seven slot skewed armature to minimize magnetic cogging for quiet operation and long life. Precision made cut-steel gears in gearbox for Improve tracking precision.
• Bearing and Shaft – Main shafts are made from 1.57″ diameter steel tubing with .40″ wall thickness with two preloaded 2.68″ O.D. tapered roller bearings on each axes
• Precision worm drive system – .75″ pitch dia. precision made steel worm preloaded with two .87″ OD ball bearings to minimize run-out (a source of periodic error). 255 tooth 6″ pitch dia. precision made worm wheel with enveloping brass teeth
• Spring loaded DEC worm to minimize backlash and makes guiding easy.
• 4 point RA and DEC clutch system for no-slip pointing precision
• Autoguide port, PC port and auxiliary ports located on the electronic pier for long exposure astrophotography
• Latitude range: 10º to 65º northern or southern hemispheres
• RS-232 communication port on hand control to control the telescope via a personal computer
• Includes NexRemote telescope control software, for advanced control of your telescope via computer

About Celestron Schmidt-Cassegrain Telescopes

Celestron’s excellent Schmidt-Cassegrain telescopes are compact and portable and represent the best all-purpose design for a wide variety of uses from terrestrial and deep sky viewing to astrophotography.

Catadioptrics use a combination of mirrors and lenses to “fold” (reflect) the light path and form an image. In a Schmidt-Cassegrain, the light enters through a thin aspheric Schmidt correcting lens. It then strikes the spherical primary mirror. It is reflected back up the tube and intercepted by a small secondary mirror which reflects the light out an opening in the rear of the instrument where the image is formed at the eyepiece.

Catadioptrics are the most popular and most modern type of telescope optical design and are marketed throughout the world in 3.5″ and larger apertures. Catadioptric telescopes combine the practical advantages of lenses and mirrors while eliminating their disadvantages. They offer the clarity and contrast of refractors with the low aberration of reflectors. Catadioptrics have an average focal ratio of f/10, which is wide enough for all types of photography. They are also easier to maintain because all optical elements are solidly mounted and rigidly collimated. Catadioptric telescopes provide the best possible combination of light gathering power, long focal length, portability, and affordability.

 

Schmidt-Cassegrain Advantages

• Very versatile, best all-purpose telescope design
• Combines the optical advantages of both lenses and mirrors while eliminating their disadvantages
• Excellent optics and razor sharp images over a wide field
• Excellent for deep sky observing and astrophotography as well as terrestrial viewing
• Very good for lunar, planetary and binary star observing
• Focal ratio generally around f/10, it also has the best near focus capability of any type of telescope
• Closed tube design reduces image-degrading air currents
• Extremely compact and portable
• Easy to use, durable and virtually maintenance free
• Large apertures at reasonable cost and less expensive than equivalent aperture refractors
• More accessories available than with other types of telescopes

Schmidt-Cassegrain Disadvantages

• More expensive than Newtonians of equal aperture
• Slight light loss due to secondary mirror obstruction compared to refractors The Maksutov-Cassegrain is similar to the Schmidt-Cassegrain with essentially the same advantages and disadvantages. It uses a thick meniscus correcting lens with a strong curvature and a secondary mirror that is usually an aluminized spot on the corrector. The Maksutov secondary

 

All-Star Polar Alignment Technology
German Equatorial Mounts (GEM) have long since been recognized as the mount of choice for astrophotography. Needing to track in only one axis for long exposures; adjustable counterweights and tube position for perfect balance, the GEM has few shortcomings when it comes to imaging. In order to do long-exposure astro-imaging, an equatorially aligned telescope is needed to allow your telescope to properly track the motion of the sky. However accurate tracking still depends on an accurate polar alignment. Even with a visible star very near the North Celestial Pole (NCP), the true celestial pole can be a very elusive place to find without assistance.

Now select Celestron mounts can utilize a new innovative Polar alignment procedure called All-Star™. All-Star allows users to choose any bright star, while the software calculates and assists with polar alignment.

Here’s how it works.

Once your telescope is aligned with two bright stars, All-Star allows you to choose any bright star listed in the NexStar hand control to assist in accurately aligning your telescope’s mount with the North Celestial Pole. Using the telescope’s Sync function, the mount is able to point and center a bright star with a high degree of accuracy. Once centered, the mount will point the telescope to the exact position that the star should be if the mount were precisely polar aligned. By simply adjusting the mounts altitude and azimuth controls to re-center the star in the center of the eyepiece, you are actually moving the mounts polar axis to the exact position of the North Celestial Pole.

 

FAQ’s

 Can I use Polaris to polar align my telescope?

Since Polaris is very close to the NCP and not very bright, it is actually not a recommended star for the “All-Star” method. The advantages of being able to use stars other than Polaris are two-fold:

Polaris is not always visible. So not only can you use a variety of other stars but they are also brighter and more prominent.
The star you choose will be farther away from the NCP thus allowing for greater accuracy when centering the star in your eyepiece.

Which stars are best to use for polar aligning?
For best results choose a bright alignment star that is near the Meridian, preferably close to the celestial equator. Try to avoid stars that are close to the west/east horizon or directly overhead because they can be more difficult to center using the mount’s altitude and azimuth controls. Also stars too near the celestial pole are less accurate than those further away.

Will I lose my alignment after I polar align?
No, the mount will retain its alignment but some amount of accuracy may be compromised depending on how much the mount has been moved during polar alignment. Although the telescopes tracking may be very good, pointing accuracy may need to be improved, especially if you are trying to locate small objects on a CCD chip.

What are the steps to polar align my telescope using “All-Star” polar alignment?

• Align the telescope with the sky using the “Two-Star Alignment” method.
• Select a suitable bright star from the Hand Control’s database and slew the telescope to the star.
• Press the Align button and select Polar Align => Align Mount from the list.
• The telescope will then re-slew to the alignment star and ask you to center it in the eyepiece in order to “Sync” on the star.
• The telescope will slew to the position that the star should be if it were accurately polar aligned.
• Use the mounts altitude and azimuth adjustments to place the star in the center of the eyepiece and press the Align button.
• Update the telescope’s star alignment if necessary.