Equipment Library

The Seattle Astronomical Society maintains a library of small and medium size telescopes that may be checked out for a period of 1 month by members in good standing. If you are new to astronomy, this is an excellent way to learn how to use a telescope and to begin viewing the wonders of the night sky, without having to invest immediately in a telescope of your own. To check out a telescope, please check out our equipment available for loan.

If you have any questions about borrowing equipment, or do not see a specific piece of equipment please reach out to our Equipment Manager.

Available Immediately

All our equipment is currently on loan to other members.

Available Soon

Available Eventually

The following list of equipment is currently loaned out to a member, and may include other members waiting to also borrow.

Orion StarBlast 4.5

Loan ends in 36 days on September 28, 2019 (Saturday).

The Orion StarBlast 4.5 EQ reflector telescope is suitable for beginner and intermediate astronomers. It comes with a sturdy EQ-1 equatorial tracking mount and adjustable-height tripod. Included are two eyepieces from the Orion Expanse series - a 15mm and 6mm - which have a large 66 degree apparent field of view. The included 15mm Expanse telescope eyepiece provides 30x power magnification, while the 6mm Expanse eyepiece bumps up the power all the way to 75x magnification.  An included Orion EZ Finder II reflex sight makes it easy to effectively aim the StarBlast 4.5 Equatorial Reflector Telescope anywhere in the night sky. The EZ Finder II projects a small red-dot onto a viewing window so all you have to do is move the telescope until the red-dot is aimed at the area of sky you wish to view through the telescope.

Orion SkyQuest XT10g - Computerized GoTo Dobsonian

Currently there are 1 requests to borrow this.

The SkyQuest XT10g features GoTo pointing. It features a 254mm (10") aperture, 1200mm focal-length parabolic mirror (f/4.7).

Assembly is straightforward, but please note: This is a heavy and bulky telescope. The base is large and weighs nearly 40 lbs. The optical tube weighs 30 lbs and is about 12 inches in diameter by 48 inches long. It may require 2 people to lift it and a bigger vehicle to transport it. Handles on the Dobsonian base's front and side panels help to lift and carry the heavy base. Assembly is done by lifting the 30 lb. XT10g telescope optical tube into the Dobsonian base and locking it in place with a hand knob. A two-star alignment must be done to orient the telescope to the sky for GoTo operation. 

Our Orion SkyQuest XT10g GoTo Dobsonian Loaner Package includes an EZ Finder II reflex sight, three high quality eyepieces, and several useful accessories. The 10" primary mirror is center-marked to make precise alignment of the optics (collimation) easier to achieve (a quick collimation cap. is provided in the loaner package). 

Orion StarMax 127 EQ

Currently there are 2 requests to borrow this.

The StarMax 127 telescope is a Maksutov-Cassegrain design that folds a long focal length into a relatively short and easy to handle optical tube. The long focal length (1540mm) makes it easy to reach high magnification for observation of the moon and planets. The 127 mm aperature is large enough for nice views of brighter deep sky objects.  Includes an adjustable tripod and equatorial mount with manual slow-motion controls.

Currently Unavailable

All our equipment is in good condition!

Telescope Types

Types of telescopes

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What are those numbers?

Types of telescopes

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The f-ratio is the focal length divided by the diameter of the telescope. Magnification is the focal length of the telescope divided by the focal length of the eyepiece.

Example

To find the f-ratio of a telescope 10 " in diameter with a 45" focal length:

Divide 45 " F.L. by10" D. to get an f-ratio of 4.5.

Compute Magnification

First, convert focal length to mm: 45" = 1146 mm, then:

1146 mm focal length divided by 35 mm eyepiece equals 33 magnification.

More Information

If you are interested in learning more about telescopes, we recommend: