Observatory Series

UL40SO 40" f/3.3 Observatory-Class Telescope

A complete observatory-class telescope system that combines massive 40" aperture with integrated Smart Finder observing assistance. Featuring plate-solving Smart Finder technology, 27-point flotation mirror cell, and observatory-grade all-metal construction. Built for serious observatory programs, advanced observing, and large-aperture imaging workflows.

Real-time sky guidance helps plan efficient observing sessions.

f/3.3: $69,000 USD

Ready to commission your observatory?

50% deposit required ($34,500 USD)

Consult with an Observatory Specialist
Sandwich Mirror Smart Finder All Metal GoTo System

At 40 inches of aperture with a fast f/3.3 optical system, the UL40SO delivers extreme light-gathering power in a practical observatory installation. This is not just about seeing more. It makes professional observatory-class apertures achievable for educational institutions, research programs, and serious amateurs who previously had to settle for far less. The UL40SO is built for permanent and semi-permanent observatories, with portable deployment possible when needed. It is well suited for research and education programs, public outreach, advanced visual observing, large-aperture EAA, and astrophotography.

Aperture

1016mm (40")

Focal Ratio

f/3.3

Resolution

0.11 arcsec

Light Gathering

21,000x

System Weight

~365 kg

Observatories

Purpose-built for permanent and semi-permanent observatory installations, with portable deployment possible when needed.

Research & Education

Ideal for educational institutions and research programs seeking uncompromised aperture with intelligent pointing and observing assistance for students and researchers.

Public Outreach & Star Shows

Smart Finder "Star Show" programs and intelligent routing support public outreach events, reducing setup time and maximizing observing time.

Advanced Observers & Astrophotographers

With 21,000x the light-gathering power of the human eye, the UL40SO supports advanced visual observing, large-aperture EAA, and astrophotography.

SkyHub Pro Smart Finder, Intelligent Observing Assistance

The integrated SkyHub Pro Smart Finder adds intelligent pointing and observing assistance to the UL40SO. Featuring a dedicated high-speed imaging module, the Smart Finder enables one-button automated alignment with integrated plate solving, reducing the need for manual star centering.

Real-Time Star Show Experience

Dynamically generated "Star Shows" create observing sessions based on your location, date, and current sky conditions. Examples include Messier Marathon, Galaxy Evolution, and Tonight's Best. Each session is intelligently optimized to maximize observing time and minimize unnecessary slewing. Every observing session is uniquely generated, so no two nights are ever the same.

Live Stacking & Processing

Advanced real-time image processing with sigma-clipping, HDR stretching, and progressive stacking reveals faint deep-sky objects within seconds. Planetary imaging includes multi-layer wavelet sharpening for high-resolution detail extraction.

System Integration

The system supports dual-camera operation, FITS export, a 10,000+ object database, and real-time visibility calculations. The Smart Finder system helps coordinate the observing workflow and handles technical complexity so you can focus on exploring the universe.

Exclusive Sandwich Mirror Technology

The lightweight sandwich mirror design reaches thermal equilibrium dramatically faster than a solid mirror of the same aperture, minimizing the thermal gradients that cause image distortion. The structure itself is passive, so it never introduces vibration into the optical path.

Why this matters

One of the primary limitations in large-aperture telescopes is "mirror seeing," the turbulence caused by temperature differences between the mirror and the surrounding air. A thick solid mirror may never fully reach equilibrium in changing conditions, preventing it from achieving its full optical performance. For smaller apertures, the sandwich design typically requires no active cooling. At 40 inches, the scale of the system makes ambient shifts more significant, particularly where temperatures change rapidly between day and night. Active pre-conditioning brings the mirror close to ambient before observation, and the lightweight structure then maintains stable performance passively during the session. In practice, diffraction patterns stabilize within tens of minutes rather than requiring hours of cooling.

27-Point Flotation Mirror Cell

Fully engineered flotation mirror cell with sling lateral support and 90-degree pivoting edge supports. Ensures uniform mirror support, eliminates stress-induced deformation, and prevents "potato chip" astigmatism. The mirror cell is completely independent from the collimation system.

Enhanced Optical Coatings

96% enhanced reflective coatings on both primary and secondary mirrors with precision dielectric overcoats. Maximum light throughput, improved contrast and brightness, with excellent durability and environmental protection.

All-Metal Observatory-Grade Construction

CNC-machined components with FEA-optimized structural design. 6063-T6 aluminum truss system, steel mirror cell, aluminum alloy OTA and mount, and stainless steel rocker. Extremely rigid, mechanically stable, and built for long-term observatory use.

Advanced GoTo Control System

State-of-the-art OnStep or SiTech controller with WiFi, Bluetooth, INDI/ASCOM support. Compatible with SkySafari, Stellarium, and more. Includes dedicated smart hand controller with ~30,000 objects, sidereal/lunar/solar tracking, and park/unpark functions.

UL40SO in observatory installation UL40SO structural detail UL40SO truss assembly UL40SO dual-speed Crayford focuser UL40SO 27-point flotation mirror cell UL40SO Smart Finder with plate-solving technology
Ark, Founder and Director of the LiJiang Observatory, standing next to the UL40SO The Lijiang Observatory Team with the UL40SO UL24SO 24 inch Observatory System with Renishaw encoders Ark taking a peek from the UL40SO
Optical Design Newtonian Reflector
Optical Diameter 1016mm (40")
Focal Length ~3352mm
Focal Ratio f/3.3
Eyepiece Height at Zenith ~2570mm (~101")
Optical Quality Diffraction Limited (Strehl ≥ 0.95 typical, 1/10 lambda PV secondary)
GoTo Controller OnStep / SiTech with WiFi & Bluetooth
Focuser 2" dual-speed linear bearing Crayford
Secondary Obstruction 310mm / 30% by diameter / 9% by area
Mirror Coatings 96% Enhanced on both primary and secondary
Tube Material 6063-T6 Aluminum Alloy truss, aluminum alloy OTA/mount, structural steel mirror cell, stainless steel rocker
Tube Length ~3000mm
Weight (OTA) ~275 kg
Weight (Mount & Rocker) ~90 kg
Weight (Assembled) ~365 kg
Power Supply Control: 12 VDC 2A, 5.5-2.1/2.5mm; Motor: 24 VDC 5A, 5.5-2.5mm
Rayleigh Limit 0.11 arcsec
Dawes Limit 0.114 arcsec
Limiting Magnitude 16.8
Max Magnification 2000x
Light Gathering Power ~21,000× (compared to the human eye)
Accessories 9x50 Finder, Shroud (optional)
Other Features 8-point whiffletree lateral support, push-pull brass knob collimation

Add these when ordering, or contact us at info@hubble-optics.com

View all 8 accessories

Carbon Fiber Truss Tubes (Lower Stage)

$2,000

Carbon Fiber lower-stage truss tubes for the UL40SO. Stronger and lighter than aluminum where the load is heaviest.

Available with UL40SO order

Red Dot Finder Scope

$45

Light weight Red Dot Finder with brackets and dovetail. Simple, effective, and easy to adjust. Free shipping with system.

Available with UL40SO order

9x50 Illuminated Finder Scope

$120

Top quality 50mm achromatic finder with dovetail bracket. Scale markings and adjustable red illumination. +$25 shipping.

Available with UL40SO order

Shroud

$300

Top quality Nylon/Lycra blend, sized for the UL40SO. Blocks stray light for better contrast. Free shipping with system.

Available with UL40SO order

5-Star Artificial Star

$22

Essential collimation tool. Free shipping when ordered with system.

Available with UL40SO order

Scope Storage Cover

$300

Sized for the UL40SO. Polyurethane-coated nylon, light reflecting, water and dust resistant. Full protection in storage and in the field. Free shipping with system.

Available with UL40SO order

Mirror Cover

$150

Sized for the UL40SO primary mirror. Strong plastic mirror cover. Free shipping with system.

Available with UL40SO order

Light Baffle

$200

Sized for the UL40SO. Reduces stray light for improved contrast. Free shipping with system.

Available with UL40SO order

Discuss Accessories with a Specialist
There's a 50% deposit for the base system, and the full payment for the optional accessories at order time. The rest including shipping will be paid before delivery (about 90 days after the deposit) via a PayPal invoice or wire transfer. Please note that the 90-day delivery is the estimated production lead time and does not include shipping transit time. The UL40SO will be shipped in custom wooden crates designed to protect the optical components and structure during transit.

Worldwide Shipping Available

We provide white-glove shipping service globally. Contact our observatory specialists for a custom shipping quote based on your location and installation requirements.

Request Shipping Quote