The Large-Sized Telescope collaboration inaugurated a completed four-telescope array at Spain’s Roque de los Muchachos Observatory on La Palma on 15 October 2026. The milestone finishes CTAO-North’s four 23-meter instruments, but technical testing, commissioning and formal acceptance must still be completed before routine scientific operations begin.
What was inaugurated at La Palma
The new array consists of LST-1, LST-2, LST-3 and LST-4, the four Large-Sized Telescopes assigned to the northern site of the Cherenkov Telescope Array Observatory (CTAO). Together they form CTAO-North’s low-energy core. Construction completion is therefore a major engineering milestone, not a declaration that the array is already in regular service.
As an Amazon Associate I earn from qualifying purchases.
Each telescope uses a 23-meter reflector with approximately 400 square meters of reflecting area. Every camera contains 1,855 photomultiplier tubes. A telescope is about 45 meters tall and weighs approximately 100 tonnes, yet its drive system can reposition it across the sky in about 20 seconds. That rapid movement is important when the array receives an alert about a short-lived gamma-ray event.
Recommended Free Tools
How the La Palma telescopes see gamma rays
They measure atmospheric light, not gamma rays directly
Very-high-energy gamma rays are absorbed in Earth’s atmosphere. When one enters the atmosphere, it initiates a cascade of secondary particles. As those particles move through the air, they produce a fleeting flash of Cherenkov light. The LST mirror focuses that light onto the fast camera, and the pattern recorded by the photomultiplier tubes allows researchers to infer the original gamma ray’s direction and energy.
#1 Best Overall
- 【Excellent Optics】Astronomical telescope features 80mm aperture 600mm(f/6.7) focal length-The big aperture can capture more light; high transmission multi-fully coated optical lens can improve light transmittance, reduce the reflection of light. It will bring you more bright and clear images.
- 【Portable & Stable】Our refractor telescope has a backbag, an adjustable aluminum tripod and an upgraded phone adapter. All accessories can be packed into the bag, which is convenient for you to carry and storage for traveling. The tripod is stable and the height can adjust from 17.7" to 52", which is suitable for adults and kids. With the phone adapter, you can take amazing photos through your phone.
- 【Easy to Operate】 This telescope is easy to assemble even for astronomy beginners and kids. You can set up easily with the detail installation manual and video. No tools are required. It’s a great astronomy gift telescope for adults, astronomy enthusiasts, beginners and kids 8-12.
- 【Optimum Magnification】Our telescope for kids and adults is equipped with two replaceable excellent-quality eyepiecesa (20mm and 9mm) for 30X and 66X magnification. A moon filter transmits only 13 percent of the incoming light and improving contrast. Also with 5x24 finderscope, you can locate objects easily. A great option for astronomy lovers to explore the moon, Saturn and Jupiter.
- 【Satisfaction Service】We provide 3 years satisfaction service. If you have any questions about the product and service, please feel free to contact us to get 24-hour technical support from our expert team. Whether observing moon or viewing planets, our telescope can meet your all needs. It’s a great telescope for adults & 8-12 kids & astronomy beginners.
Why the camera and reflector are both large
The large mirror increases the amount of faint Cherenkov light collected from each shower. The densely instrumented camera then records the shower’s brief image quickly enough for reconstruction. The result is an indirect measurement: scientists work backward from the atmospheric cascade to estimate the properties of the incoming gamma ray.
Why four telescopes are more useful than one
When LST-1 through LST-4 observe the same atmospheric shower from different positions, the collaboration can compare the images produced at each viewpoint. This stereoscopic approach improves the reconstruction of the shower’s geometry, which in turn improves estimates of the gamma ray’s arrival direction and energy. Multiple views also help distinguish genuine gamma-ray showers from background events produced by cosmic rays.
Rank #2
- Superior Optics: 400mm(f/5.7) focal length and 70mm aperture, fully coated optics glass lens with high transmission coatings creates stunning images and protect your eyes. Perfect full positive telescope for astronomers to explore stars and moon.
- Magnification: Come with two replaceable eyepieces and one 3x Barlow lens.3x Barlow lens trebles the magnifying power of each eyepiece. 5x24 finder scope with mounting bracket and cross-hair lines inside make locating objects easily.
- Wireless Remote: This refractor telescope includes one smart phone adapter and one Wireless camera remote to explore the nature of the world easily through the screen and take amazing celestial images.
- Adjustable Tripod: This telescope allows for many different viewing positions with a adjustable aluminum alloy tripod and a carry bag, the telescope and tripod can fit inside the bag for easy traveling and storage.
- Satisfaction: Buy with confidence from a leading manufacturer.
The four-instrument arrangement is consequently more than four times the observing area of a single telescope in practical scientific value. It provides the separated viewpoints needed for stronger event reconstruction while retaining the LST design’s emphasis on low-energy gamma rays and rapid response.
How the LST array compares with the wider CTAO plan
The La Palma instruments occupy one part of a much larger observatory concept. The LSTs target approximately 20 GeV to around 3 TeV. The complete CTAO design is intended to cover about 20 GeV to 300 TeV with more than 60 telescopes distributed between northern Spain and southern Chile.
Rank #3
- SMARTPHONE-POWERED SKY TOUR: No experience needed! Just dock your phone, launch the StarSense Explorer app, and follow the on-screen arrows to locate stars, planets, nebulae, and more.
- PATENTED STARSENSE TECHNOLOGY: Unlike other astronomy apps, StarSense Explorer uses sky recognition technology to turn your phone into a celestial navigation system, analyzing star patterns overhead to pinpoint your telescope’s position.
- TONIGHT’S BEST TARGETS, INSTANTLY: The app generates a curated list of the top objects to see based on your time and location. See planets, bright nebulae, galaxies, and star clusters from the city—and even more from dark skies.
- SIMPLE SETUP, SMOOTH TRACKING: Features a manual altazimuth mount with altitude slow motion adjustment with a sliding rod. Follow the on-screen arrows to your target; when the bullseye turns green, you can view it clearly through the eyepiece.
- 114MM REFLECTOR WITH IMPRESSIVE VIEWS: The 4.5" Newtonian reflector with high-reflectivity coatings delivers sharp, vivid views of the Moon, planets like Jupiter and Saturn, and deep-sky favorites like the Orion Nebula and Andromeda Galaxy.
| Aspect | Four-LST sub-array at La Palma | Wider CTAO concept |
|---|---|---|
| Primary energy role | Approximately 20 GeV to around 3 TeV | About 20 GeV to 300 TeV across the full facility |
| Scale and location | Four 23-meter telescopes at Roque de los Muchachos Observatory, La Palma | More than 60 telescopes planned across northern Spain and southern Chile |
| Sensitivity and angular resolution | Quantitative values were not stated in the 15 October 2026 announcement; stereoscopic viewing is intended to improve reconstruction | Quantitative values were not stated in the 15 October 2026 announcement |
| Transient response | Each telescope can reposition in about 20 seconds | A single full-array response time was not stated |
| Stereoscopic reconstruction | Four telescopes can view one shower from different positions | Additional telescope classes extend coverage and event reconstruction across a broader energy range |
| Operational status | Construction complete; testing, commissioning and formal acceptance remain | Long-term observatory concept still being built out |
Is the CTAO-North array operating yet?
Not as a routine, formally accepted facility. The inauguration marks completion of construction. Engineers and scientists still need to finish technical testing, commission the instruments, verify performance and complete formal acceptance. Those steps determine when regular observing can begin and which capabilities are available to the wider scientific programme.
This distinction matters because an instrument can produce useful data during commissioning while still undergoing calibration and operational checks. The La Palma array should therefore be described as completed and entering the commissioning phase, rather than as fully operational.
Rank #4
- Superior Optics: Dianfan astronomy telescope features a focal length of 800 mm and a fully coated 90 mm objective lens. The large aperture gathers more light for brighter, clearer views, high-transmission coatings enhance contrast and color for sharp, vivid images for an enjoyable stargazing experience
- Powerful Magnification: With two eyepieces and a 3× Barlow lens, this telescope offers 32×–240× magnification. It allows you to observe craters and lunar seas on the surface of the Moon. With the 45° zenith mirror, images are upright and correctly oriented for terrestrial viewing, making distant targets details easier to observe. The telescope is ideal for beginners and astronomy enthusiasts
- Quick Setup & Beginner-Friendly: User-friendly design with clear instructions makes assembly simple—ready in about 15 minutes. Smooth focusing helps you quickly locate targets. Perfect for families to enjoy stargazing and explore the night sky together
- Portable & Versatile: Lightweight design with a sturdy stainless steel tripod ensures stable, steady viewing. Easy to carry in the included bag, making it perfect for travel and outdoor adventures. Suitable for stargazing, birdwatching, wildlife observation, and exploring cityscapes
- Professional Astronomical Telescope: The Dianfan 90x800 telescope combines quality , functionality and reliability. It delivers high-resolution views that bring the universe closer. Designed for adults high powered, it inspires interest in astronomy and science while encouraging exploration of the starry sky
What LST-1 has already demonstrated
LST-1 began astronomical observations during commissioning in 2019. Its performance work has used the Crab Nebula and a pulsar, giving the collaboration established targets for checking how accurately the telescope reconstructs gamma-ray events.
During a bright flare in December 2023, LST-1 also detected very-high-energy emission from the quasar OP 313. The reported redshift was 0.997, corresponding to radiation that travelled roughly eight billion years before reaching Earth. That observation demonstrates the scientific reach already achieved by an individual LST during commissioning, while the four-telescope array is intended to improve the quality and reliability of such measurements.
Best Value
- BRIGHT, SHARP VIEWS ANYWHERE: Unlike many beginner telescopes, this quality refractor features fully coated glass lenses and a 70mm aperture for crisp, clear views of the Moon, planets, and daytime scenery—all in a lightweight, travel-ready design.
- PERFECT FIRST TELESCOPE FOR BEGINNERS: Designed for adults and kids to enjoy together, this beginner-friendly telescope sets up in minutes and delivers rewarding views with no prior experience required.
- EASY NO-TOOL SETUP: No complicated assembly or tools needed. The full-height tripod and telescope tube set up in seconds and pack neatly into the included backpack—so you’re always ready to observe on the go.
- DUAL EYEPIECES FOR VERSATILE VIEWS: Includes 20mm and 10mm eyepieces for wide and close-up views of celestial and terrestrial targets. Spot craters on the Moon at night or wildlife during the day.
- BONUS BACKPACK AND SOFTWARE: Includes a padded backpack with room for accessories, a finderscope, star diagonal, eyepieces, and a free download of Starry Night software to help you identify celestial objects and plan your next stargazing session.
What scientists hope to discover
The LSTs are designed to respond to transient and variable sources as well as to build longer-term measurements of persistent objects. Planned research targets include:
- Gamma-ray bursts and other short-lived transients
- Supermassive black holes and their jets
- Neutron stars
- Cosmic-particle accelerators
- Possible dark-matter signals
These are scientific search objectives, not guaranteed detections. A dark-matter signal, for example, would require evidence that survives background rejection and alternative astrophysical explanations. Likewise, finding a source in the LST energy band does not by itself identify the mechanism producing its particles.
Why this milestone matters for extreme-universe research
The four-telescope array gives CTAO-North a dedicated low-energy capability with rapid pointing and stereoscopic views. It links the engineering scale of 23-meter mirrors to a measurement technique that can probe violent, distant environments indirectly through atmospheric light. The completed instruments now move the project from construction toward the more demanding stages of calibration, commissioning and scientific acceptance.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Once those stages are complete, the La Palma sub-array will contribute one part of CTAO’s planned northern-and-southern network. Its results will be strongest when the four LSTs’ low-energy observations are combined with the broader facility’s coverage extending toward 300 TeV.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
