Celestron's NexStar 4SE 125mm f/13 Maksutov-Cassegrain GoTo Telescope is a powerful, versatile, and user-friendly catadioptric-style scope that can be used for observing everything from the moon and planets to bright deep-sky objects like stars, galaxies, and nebulae. Using Celestron's proprietary StarBright XLT multicoating system, light transmission is increased throughout the entire optical path with anti-reflection multicoated lenses, highly reflective multicoated mirrors, and crown optical glass elements. Similar to their Schmidt cousins, the Maksutov design exchanges the conventional front corrector plate with a convex meniscus lens, which results in a smaller secondary mirror—limiting obstruction and increasing contrast, while eliminating the need for periodic collimation. While the focal ratio is a relatively slow f/13, the scope's optical performance, added to the mount's precision tracking system and integrated equatorial wedge, allows it to be a competent astrophotography/imaging platform for the moon and planets.
Driving the dual servo motors on the mount is the brain of the NexStar 4SE: the iconic NexStar+ computer hand controller. Packed with 40,000+ celestial objects, it can hold up to 100 additional user-defined destinations and is updatable via the Celestron website. It has multiple alignment procedures to get you observing fast—including the super-easy SkyAlign system. Capable of being used in the Northern or Southern Hemispheres, the NexStar has sidereal, lunar, and solar tracking speeds to accurately follow near- and deep-sky objects, plus nine slew speeds and the ability to automatically trigger a camera's shutter release for Fastar or piggyback wide-field photography or conventional prime-focus astrophotography.
Performance
4" (102mm) aperture
f/13 focal ratio
1325mm focal length
Maksutov-Cassegrain optical system
Front convex meniscus lens corrects spherical and chromatic aberrations and comas (off-axis aberration) across the entire field of view
Smaller secondary mirror versus Schmidt-Cassegrain reduces obstructions and increases contrast
BK7 optical glass primary mirror
StarBright XLT optical coatings: Multilayer aluminum/SiO2 (quartz)/TiO2 (titanium dioxide) mirror coatings with flat reflectivity across the light spectrum for both astrophotography/astroimaging and visual observation
Multilayer MgF2 (magnesium fluoride) and HfO2 (hafnium dioxide) anti-reflective lens coatings
High-transmission water white glass corrector lens with 97.4% light transmission
Resolution: Rayleigh: 1.36 arcsec / Dawes: 1.14 arcsec
Secondary mirror obstruction: 1.25", 34.4% by diameter, 11% by area
Internal 90° flip mirror: With the mirror flipped up, the 90° angle puts head in a comfortable viewing position when scope is pointed at or near the zenith; lay the mirror down to direct light to the visual back for astrophotography/imaging
NexStar+ Computer Controller
2-line, 16-character LCD display
19 fiber optic backlit red LED buttons
Database of over 40,000 celestial objects plus 100 user defined
Automatically slew to planets, stars, constellations, and a variety of catalogs
Camera control: For piggyback wide-field or conventional astrophotography through the optical tube assembly, the controller can automatically trigger the shutter release to capture the image
Anti-backlash compensation programs out play between gears for more precise tracking
Tour Mode: Shows a selection of the most popular objects for the time and date you are observing
Constellation Tour: Allows you to take a tour of all the best objects within a particular constellation
Alignment procedures: SkyAlign, Auto 2-Star, 1-Star, 2-Star, and Solar System
SkyAlign alignment: Takes minutes, with minimal effort or experience—point the telescope at three bright objects in the sky, and the telescope does the rest
Nine slew speeds: 4°/sec, 2°/sec, 1°/sec, 0.5°/sec, 2x, 4x, 8x, 16x, and 32x
Sidereal, Solar, and Lunar tracking rates for observing the fast-moving moon, to slower-moving deep-space subjects
Tracking modes: Alt-Az (default, for general GoTo use), EQ North (use for long-exposure astrophotography in Northern Hemisphere with EQ wedge engaged), EQ South (use for long-exposure astrophotography in Southern Hemisphere with EQ wedge engaged), Off (no tracking when using as a terrestrial spotting scope)
RS-232 communication port allows for computer control
Flash updatable via the Celestron website
Database Details:
Solar system objects including the sun, moon, and planets
Named objects
Stars: Asterims, variable stars, double stars, named stars
Caldwell catalog
Messier catalog
NGC catalog
SAO catalog
Constellations
Mount & Tripod
Mount:
Single-fork alt-az
Dual-axis servo motors allow for precise tracking with virtually no vibration
Motor resolution: 0.26 arcsec
Optical encoders track mount movement to improve tracking and GoTo accuracy while allowing the mount to maintain alignment when moved manually
Communication ports: Autoguider port, Aux port, hand controller
Runs on eight user-supplied AA batteries or optional 12 VDC power supply
Tripod:
Stainless steel legs
Adjustable height accommodates a variety of observation positions or users
Built-in equatorial wedge enables more precise tracking accuracy during long-exposure astrophotography
Tray holds accessories such as eyepieces and filters and adds stability and vibration reduction
Weight: 4.5 kg
Included Accessories
Eyepiece:
1.25" diameter barrel
25mm focal length produces 53x magnification
Anti-reflection multicoated glass improves color rendition and contrast
Threaded barrel accepts most 1.25" astronomical filters
Fold-down rubber eyecup for use with or without eyeglasses
StarPointer Finder
Projects a single red dot in line of sight
Unmagnified to make finding objects faster and easier
Used primarily for alignment process
102mm Maksutov-Cassegrain Telescope
1325mm Focal Length, f/13 Focal Ratio
StarBright XLT Optical Coating System
NexStar+ Computer Hand Controller
40,000+ Object Database with Sky Tours
SkyAlign Alignment Technology
Multiple Slew and Tracking Rates
Single-Fork Motorized GoTo Alt-Az Mount
25mm Eyepiece, StarPointer Finder
Stainless Steel Tripod with EQ Wedge