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.
- 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
- 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
- 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
- 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: 10 pounds
- 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
- Projects a single red dot in line of sight
- Unmagnified to make finding objects faster and easier
- Used primarily for alignment process