The Celestron Royal Observatory StarSense Explorer DX 100AZ is a 100mm refractor that uses Celestron’s StarSense Explorer smartphone system to guide the observer to celestial objects. The Royal Observatory Greenwich edition combines app-assisted navigation with a fully manual altazimuth mount and requires no powered telescope electronics.
100mm Refractor Optics
The 100mm aperture, 660mm focal length and f/6.6 focal ratio provide useful visual performance on the Moon, planets, double stars, clusters and brighter deep-sky objects under suitable conditions. The optics are fully coated.
StarSense Explorer Smartphone Guidance
Place a compatible phone in the StarSense dock and follow the app’s on-screen arrows to locate a selected target. The system uses the phone camera, GPS and sensors; the telescope itself remains manually moved and does not slew or track automatically.
Two Eyepieces and Erect-Image Diagonal
The 25mm eyepiece gives 26× and the 10mm gives 66×. The supplied 90° erect-image diagonal provides a correctly oriented view, while the StarPointer red-dot finder helps with setup and manual aiming.
Manual Altazimuth Mount
The DX mount includes slow-motion controls and an adjustable aluminium tripod. No batteries or mains connection are required for the mount; the smartphone must be charged separately.
Phone and App Requirements
A smartphone is not included. StarSense Explorer app compatibility can change as phone hardware and operating systems evolve, so customers should check Celestron’s current compatibility information before purchase. An activation code supplied with the telescope is required.
What Is Included?
- 100mm f/6.6 refractor optical tube with Royal Observatory Greenwich branding
- StarSense Explorer DX manual altazimuth mount and aluminium tripod
- StarSense Explorer smartphone dock and activation code
- 25mm eyepiece providing 26×
- 10mm eyepiece providing 66×
- 90° 1.25-inch erect-image diagonal
- StarPointer red-dot finderscope
- Accessory tray
- Quick setup and app documents
Please note: Only the items listed above are stated as included. A smartphone is not included with app-guided telescopes. Optional adapters, tripods, eyepieces and other accessories are sold separately unless explicitly listed.
Specifications
| Optical design | Refractor |
|---|---|
| Aperture | 100mm (3.94 inches) |
| Focal length | 660mm (25.98 inches) |
| Focal ratio | f/6.6 |
| Optical coatings | Fully coated |
| Included eyepieces | 25mm (26×) and 10mm (66×) |
| Finderscope | StarPointer red-dot |
| Star diagonal | 90° erect-image, 1.25 inch |
| Barlow lens | None stated as included |
| Highest useful magnification | 241× |
| Lowest useful magnification | 15× |
| Limiting stellar magnitude | 12.5 |
| Rayleigh resolution | 1.37 arcseconds |
| Dawes resolution | 1.14 arcseconds |
| Light-gathering power | 212× compared with the unaided eye |
| Optical-tube material | Aluminium |
| Optical-tube dimensions | 812.8mm long × 118mm diameter |
| Optical-tube weight | 2.26kg (5lb) |
| Dovetail | CG-5 style |
| Mount | Manual StarSense Explorer DX altazimuth mount |
| Tripod | Adjustable aluminium tripod with accessory tray |
| Tripod / mount weight | 4.17kg (9.2lb) |
| Maximum assembled height | Approximately 1244.6mm (49 inches) |
| Complete telescope weight | 6.44kg (14.2lb) |
| Telescope power requirements | None; smartphone power required separately |
Solar Safety
Warning: Never look directly at the Sun through this optical instrument without a correctly fitted, certified full-aperture solar filter.
Permanent and irreversible eye damage can occur. Never use an eyepiece-type solar filter and never project sunlight through the instrument. Cover or remove finder devices during properly filtered solar use.
Never leave the instrument unattended, especially when children are present.
Instruction Manuals
Official documents are supplied in StarSense app manual: English, French, German, Italian and Spanish; product setup and telescope basics documents: English.