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.

Celestron StarHopper 8

Loan ends in 24 days on July 18, 2019 (Thursday).

The Star Hopper Dobsonian telescopes are designed for beginners who seek the best possible view of the faint Deep Sky objects while on a constrained budget. These include advanced features that an experienced observer will appreciate.

 

Orion SkyQuest XT10i

Loan ends in 29 days on July 23, 2019 (Tuesday).

The Orion SkyQuest XT10i IntelliScope Dobsonian Reflector features a fairly large 10" apperture mirror combined with the ease of use of a Dodsonian mount. The telescope includes altitude and azimuthal encoders and a computer controller for easy two start configuration and push-to navigation. With the Orion SkyQuest XT10i IntelliScope Computer Controller, the user can select an object to view from the controller's 14,000+ object database. A big, 9x50 finder scope is included to help aim the telescope. Three included telescope eyepieces, a 25mm, 17mm, and 9mm Sirius Plossl, provide you with views between 48x and 120x respectively. This telescope also includes a full aperture solar filter for safe solar viewing.

Orion SkyQuest XT10g - Computerized GoTo Dobsonian

Currently there are 2 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). 

Currently Unavailable

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 Stormthecastle.com

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: