The SkyWatcher Stargate 20" collapsible Dobsonian represents the ultimate combination between light gathering, precision and portability for outstanding performance and resolution. The truss structure is compact allowing for easy transport of this large telescope whilst looking for the perfect dark, pristine sky.

Now available with either the traditional hand controller or Synscan Wi-Fi for smartphone and computer control.

NOTE: The Wi-Fi version does not include the hand controller.

The outstanding light gathering of the mirror and the superior resolution allows amazing journeys through the universe, offering spectacular observations of tangled gas filaments in nebulae, fine galaxy details and remarkable planet structures. Despite the size of the mirror, the telescope is easy to assemble following the step by step instructions and video.

To top it off, the SkyWatcher Stargate is equipped with a 2″ Crayford dual speed focuser for smooth and precise focusing and a focuser-locking screw.

The Freedom Find technology (dual-encoder) allows the telescope to be moved manually whenever the user wishes, but without losing any of the pre-set alignment.

Parabolic Primary Mirror

The most extraordinary feature of the Stargate is the technology used in the mirrors which are made up of borosilicate glass which has a very low expansion coefficient, reducing the stress caused by thermal gradients. The mirror is extremely light and thin but the glass ribs beneath minimise the glass deformation, thus allowing continuous high performance from all the telescope angulations. Also, the small thickness of the mirror allows a much quicker cooling time compared to the standard monolithic mirrors. The secondary mirror has a honeycomb structure that follows the concept of the primary mirror: lightweight, rigid and quick to cool down.

Both the mirrors are aluminised and in order to protect the reflective treatment over the years, the coatings are protected by a thin layer of quartz (silicon dioxide). This protection is needed as the mirrors are exposed to external elements due to their position in an open truss tube. Sky-Watcher is one of the few companies in the world that uses this particular technology.

Accessories in the box:

SynScan hand controller with cables
12V power cable with lighter socket plug
Finderscope 9X50 straight version
Eyepiece 2″ LET 28mm (68x) – apparent field of view 56°
Eyepiece 1.25″ Super Plossl 10mm (190x) – apparent field of view 52°
Eyepiece adapter from 2″ to 1.25″ with M42 thread
2″ tube extension
Collimation eyepiece
User manual

Specifications

Optical design	Newtonian
Aperture	508 mm
Focal length	2000 mm
Focal ratio	f/3.9
Secondary mirror	136 mm (minor axis)
Obstruction	26.8%
Resolving power	0.24 arc seconds
Stellar limiting magnitude	15.53
Max magnification	1016 x
Light gathering power	5267 times the human eye
Focuser	Crayford 2" dual speed
SKU	SWDOB500CGT
Warranty	2 years on electronic components, 5 years on mechanical parts

Included items

SkyWatcher StarGate 20" Go-To
SynScan hand controller with cable (RJ45 to RJ45) (only with Hand Controller model)
12V power supply cable with lighter plug
Finderscope 9 x 50
Eyepiece adapter from 2″ to 1.25″ with M42 thread
Eyepiece 2″ LET 28mm (71x) – apparent field of view 56°
Eyepiece 1.25″ Super Plossl 10mm (190x) – apparent field of view 52°
User manual and SynScan manual

Video

Video shot by Testar Australia

SynScan

The SynScan go-to system is a computerized system supplied with the professional SkyWatcher mounts and telescopes.

It features:

9 speeds 1x, 2x, 16x, 32x, 64x, 128x, 400x, 500x, 600x, 800x (3.3°/sec)
42,900 objects including planets, the moon, the sun, named stars, double stars, variable stars and the most famous catalogue that are Messier, Caldwell, NGC, IC & SAO
Sidereal, moon and sun tracking speeds,
Pointing Accuracy Enhancement feature (PAE)
Unknown Object Identification feature
Permanent Periodic Error Correction (PPEC) for mounts only
One, two and three stars or brightest star alignment (alt-azimuth telescope need at least 2 stars for the alignment)
Telescope parking feature
Polar allign procedure
Deep Sky Tour function that suggests a list of the most interesting deep sky objects currently visible.

SkyWatcher SynScan 5

Download the SynScan user manual

SKYWATCHER STARGATE DOBSONIANS