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Equipment Library

The Seattle Astronomical Society maintains a library of small and medium size telescopes that may be checked out 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.

See the complete equipment list in alphabetical order.


You can narrow your search of our equipment library by selecting any one of the below keywords.

Astrophotography Beginner Binoculars Camera Intermediate Maksutov Newtonian Refractor Schmidt Cassegrain Visual

All our equipment is currently on loan to other members.

Available Eventually

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

  • AWB 130mm Reflector

    Currently there are 2 requests to borrow this.

    Table Top f/5 Newtonian Telescope.

    NOTE: This scope does not include a tripod and is designed to be placed on a small table or similar support. It has an open tube and must be shielded from nearby streetlight or porch lights.

    This telescope is suitable for all ages and is a good choice for viewing the moon, planets, and bright deep sky objects. It has a Dobsonian style mounting that is compact and intuitive to use.  It is designed to be placed on a small table or similar support and does not come with a tripod.. A red-dot reflex sight and a set of eyepieces are included..

  • Celestron Echelon 16x70 Binoculars

    Currently there are 3 requests to borrow this.

    High Power Astronomy Binoculars

    Large-aperture astronomical binoculars are intended for wide angle viewing star clusters, nebula, and galaxies, but will also provide nice views of our Moon and Jupiter with it's four Galelian moons. These 70mm binoculars are heavy and an Orion parallelogram binocular mount and tripod is included. 16x magnification is sufficient to provide nice views of many deep sky objects, such as the Andromeda Galaxy (M31),, the Orion Nebula (M42),  and the Great Globular Cluster in Hercules (M13). It will not show Saturn's ring (about 30 power is required to reveal this detail).

  • Celestron NexStar 4 SE

    Currently there are 4 requests to borrow this.

    102mm (4 inch) aperture f/13 Maksutov-Cassegrain. 

    The NexStar 4 SE is a computerized - GoTo telescope that uses Celestron's user-friendly NexStar software to point the telescope to the scope to the desired object. 

  • Orion 80mm ED Refractor

    Loan ends in 93 days on May 24, 2024 (Friday).

    High Quality 80mm Refractor. Optical tube only at this time; the Mount is out for repairs. 
    Note for experienced users: The optical tube can be used with any mount with a Vixen-style saddle. Contact the Equipment Manager for more information. 

    The Orion 80ED is a small, general purpose refractor telescope that will give sharp images of the moon and planets as well as the brighter star clusters and galaxies. ED glass improves the image contrast compared to a traditional acromat. The Twilight I Alt-Az mount is easy intuitive to use.

  • Orion SkyQuest XT8 Dobsonian

    Currently there are 1 requests to borrow this.

    8" Newtonian Reflector on Dobsonain Mount.


All our equipment is in good condition!

Telescope Types

Types of telescopes

Copyright NIAAS, North Ireland Amatuer Astronomical Society

What are those numbers?

Types of telescopes

Copyright 2008-2012

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.


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: