Sky-Watcher 10" 250P Classic Dobsonian Telescope
1140The low cost, large diameter, and fast focal ratio of the 10" Sky-Watcher Classic 250P Dobsonian telescope make it an ideal dedicated telescope for wide-field, deep-space observation of faint galaxies, nebulae, and star clusters. The low-power inherent in this scope dramatically captures wide swaths of sky in a single view. the 10" Sky-Watcher 250P Classic Dobsonian makes galaxies and nebula appear to pop out of the heavens as bright, expansive masses of stars, gas, and dust. If you have never before observed through a high-quality Dobsonian scope like the Sky-Watcher 10" Classic 250P Dobsonian, you are in for a truly enjoyable, sweet experience which is exactly what you would expect from amateur astronomy!
This 10" Classic 250P Dobsonian telescope from Sky-Watcher USA is a nice size telescope with a big aperture for the whole family to use, either in your own back yard or taken to a favorite dark-sky site for better observing of night sky objects. It is so easy to operate, being a Dobsonian design of mount. Just grasp the scope and move it by hand in the general direction of the objects you want to observe. The Sky-Watcher Classic Dobsonian Telescope 254 mm/1200 mm (10"aperture and 1200 mm focal length) has a paraboloidal primary mirror to eliminate spherical aberration and a four-arm secondary mirror bracket with fine supports (0.5 mm thick), to reduce diffraction spikes and light loss. In addition, this model include a 2" focuser with a 1.25" adapter thus allowing the use of either eyepiece size. This model also include the new tension control handle which allows adjustment of the tension setting for the vertical movement.
Observing with a Dobsonian scope has been compared to shooting ducks in a gallery; it is so easy to find your target. A 9x50 mm straight-through optical viewfinder provides both magnification and light-gathering to help narrow your search. The standard-equipment backlash-free 2" Crayford Focuser provides reliable, ultra smooth focusing. Multi-coated, Super (modified Kellner) eyepieces (25 mm and 10 mm) provide a spacious field of view. To ensure mechanical ease-of-use, Sky-Watcher uses a high-performance Teflon bearing system in both axes combined with tension adjustment in altitude to facilitate setting the appropriate amount of friction, assuring smooth vertical and horizontal manual movements. Also reduces movement from accidental small bumps. This also eliminates the need for a balanced optical tube as would be required with an equatorial mount.
Sky-Watcher's Teflon bearing system is preferable to the use of ball-bearings. Ball-bearings make unintended movement of the optical tube more difficult to control. Fortunately, at low power, deep-space objects will seem to leisurely drift through the field of view of the Sky-Watcher 10" 250P Classic Dob telescope, so constant mechanical adjustment of the telescope's orientation isn't needed to keep objects in your field.
The Sky-Watcher 10" Classic 250P Dobsonian utilizes quality components throughout. The polishing process for primary and diagonal mirror yields smooth mirror surfaces ensuring good contrast, and properly corrected optics show minimum aberrations. Each primary mirror and elliptical diagonal mirror is coated with aluminum and then over-coated with hard quartz (SiO4). Additional layers of titanium dioxide (TiO2) and (SiO4) are then applied to protect the coatings. Dust covers help keep your Dob clean when not in use. The mechanical and structural components of the OTA tube and optics exhibit rigid construction and stability you will appreciate every time you observe the sky.
The summer sky is aglow with astronomical pearls: In the constellation Sagittarius several of the sky's most prominent emission nebulae can be seen well. The Lagoon Nebula (M8) is a rich aggregation of dust and gases illuminated by its central stars. This is actually an area of star formation. The Lagoon Nebula appears fiery red in astrophotographs due to the hot hydrogen gas. Located nearby is the smaller, but very beautiful Trifid Nebula (M20). The magnificent Swan Nebula (M17) is also located in Sagittarius.
The most awesome globular star cluster, M13, is located in the constellation Hercules, a bee-hive of thousands of stars swarming about a central core. Since globular clusters are no longer being formed in the universe, you are observing fossil light, a glimpse back in time. This is the brightest object of its kind and always fun to view. The globular cluster M92 is likewise very interesting and can also be found in Hercules. The winter sky holds several stunning pearls often referred to in popular culture, not only in astronomy. Our closest external galaxy, the beautiful Andromeda, perhaps the defining galaxy of the classic spiral form can essentially be seen almost in its entirety within one eyepiece field. Winter's diffuse Great Orion Nebula (M42) is the brightest emission nebula in the heavens. It is really spectacular as viewed in a 10" Classic 250P S-W Dobsonian telescope.
The preceding is just a short sampling of objects that can be seen. Many more fascinating celestial objects in our sky await you.
|Mirror Coatings:||94% Aluminum|
|Primary Aperture (mm):||254|
|Focal Length (mm):||1200|
|Secondary Diameter:||48 mm|
|Secondary Obstruction (by diameter):||25%|
|Secondary Obstruction by Area:||6%|
|Dawes Limit:||0.46 arcsecond|
|Rayleigh Limit:||0.55 arcsecond|
|Light Gathering (compared to next size down):||57%|
|OTA Outer Diameter:||11.375"|
|OTA Weight (with accessories):||28 lb|
|Dob Base Weight:||25 lb|
|Dob Base Measurements:||29" x 20.5"|
|Zenith Eyepiece Height:||48"|
|Included Finder:||9 x 50 Straight through|
|Included Eyepieces:||25 mm / 10 mm mod. Kellner|
|Magnification w/ Included Eyepieces:||48x/120x|