Celestron NexStar 9 1/4 GPS Telescope has unique design, advanced features, GOTO accuracy, and superb optics. The 9 1/4" optical tube is coupled with one of the most popular mounts in Celestron's history - the NexStar GPS series. The 9 1/4" Telescope was already a favorite among astrophotographers and discerning visual observers, but now with the carbon fiber tube and the NexStarGPS mount, it is a formidable addition to the Celestron NexStar-GPS family. The NexStar-9-1/4 was specifically designed for visual infinity focus when using 2" eyepieces and has an optimized baffle system to benefit astrophotography by minimizing vignetting at the edge of the field of view. NexStar 9 1/4 GPS longer primary focal length and lower magnification secondary mirror contribute to a flatter field of view at the focal plane and helps to further reduce optical aberrations.
Celestron NexStar 9 1/4 GPS Telescopes with SarBright XLT coating :
(models 11056-XLT and 11056-XLT-A)
With StarBright XLT Optical System Design you'll see the light!
One of the most important factors in the evaluation of a Schmidt-Cassegrain telescope 's optical system performance is its transmission - the percentage of incoming light that reaches the focal plane. The design of the XLT System accomplishes two crucial objectives: Develop a coating system that is optimized for visual use and for CCD/Photographic imaging.
There are three major components that make up Celestron StarBrightXLT high transmission optical system design:
1) Unique enhanced multi-layer mirror coatings:
Celestron mirror coatings are made from precise layers of Al (Aluminum), SiO2 (quartz) and TiO2 (Titanium Dioxide). Reflectivity is fairly flat across the spectrum, optimizing it for both CCD imaging and visual use.
2) Multi-layer anti-reflective coatings:
Coatings are made from precise layers of MgF2 (Magnesium Fluoride), and HfO2 (Hafnium Dioxide). Hafnium gives a wider band pass than Titanium, used in comparable coatings.
3) High Transmission Water White glass :
Celestron Schmidt-Cassegrain optical systems with optional StarBright XLT coatings use Water White glass instead of Soda Lime glass for the corrector lens. Water White glass transmits about 90.5% of light without anti-reflective coatings. That is 3.5% better transmission than uncoated Soda Lime glass. When Water White glass is used in conjunction with StarBright - XLT 's anti-reflective coatings, the average light transmission reaches 97.4% - an 8% improvement!
These three components of Celestron StarBright XLT coatings result in one of the finest coatings available. The peak light transmission for the systems is 89% at 520 nm. The overall system transmission is 83.5% averaged over the spectrum from 400 to 750 nm.
Click here to see details about StarBright XLT.
Specifications for Celestron NexStar 9 1/4" GPS Telescopes:
|Optical Design: || || 9.25" (235mm) Schmidt-Cassegrain|
|Focal Length: || || 2350mm|
|Focal Ratio: || || f/10|
|Coating: || || StarBright Multi-Coatings|
|Tube: || || Carbon Fiber Optical Tube|
|Display: || || Double line, 16 character Liquid Crystal Display;|
|Hand control: || || 19 fiber optic backlit Computer Hand Control|
|Port: || || RS-232 communication port on hand control|
|Database40,000+ object database: || || |
|GPS Receiver: || || 16 channel GPS Receiver|
|Fork Tine and Optical Tube Weight: || || 58 lb.|
Features of Celestron NexStar 9 1/4 GPS Telescope:
- Baffle design - Optimized for astrophotography
- Carbon Fiber Tube
- Hand Figured Optics
- Great Focus mechanism
- Unique roller bearing design
- High quality Pittman drive motors
- Autoguider port
- StarBright coatings
- Internal Slip Ring
- Auxiliary Ports
- Optical Tube Assembly Outer Rails
- Integrated Handles
- Leveling accuracy
- 16-Channel GPS
Hand Control and Software Features:
- 40000+ object database
- Compass Calibration
- Polar Alignment Routine
- Equatorial Auto Align
- Database Filter Limits
- Auto North and Level
- Wedge Align Algorithm
- Quick Align
- User-Defined Slew Limits
- Celestron NexStar 9 1/4 GPS Telescope
- 1-1/4" 40mm Eyepieces (59x)
- 1-1/4" Star Diagonal
- 9x50 Finderscope and Mounting Bracket
- 1-1/4" Visual Back
- AC Adapter (car battery adapter is included in some models)
- Heavy Duty Tripod
- NexRemote Telescope Control Software