ASTR 110L                                                                                                                                                          Fall 2009

Introduction to ASTR 110L Telescopes

 

Read:

• Ridpath, pp. 383–392

• Telescope-related sections of your ASTR 110 textbook

 

1.  Be able to identify the following parts of our lab telescopes and their functions: 

 

Base

 

Tube

 

Primary mirror

 

Secondary mirror

 

“Spider” (secondary mirror support)

 

Eyepiece

 

Focuser (knob)

 

Finder scope

 

Filters: Moon, Nebula, Red, Blue

 

 

 

2.  Know the following terms and their meanings:

 

Reflector vs. Refractor telescope

 

Altazimuthal (Alt-Az) mount vs. Equatorial mount

 

resolution

 

seeing

 

aperture

 

limiting magnitude

 

averted vision

 

 

3.  What distinguishes a “Dobsonian” design from other telescope designs?  Do Dobs have alt-az or equatorial mounts?  Are our Dobs Newtonian reflectors? 

 

 

4.  On our “8-inch Dobsonian” telescopes, which part measures 8 inches?  What advantages does an 8-inch telescope have over, say, a 4-inch telescope? 

 

 

5.  What does the number of millimeters printed on the side of our different eyepieces refer to?  How is the view through a long-focal-length eyepiece (installed on the telescope) different from that through a short-focal-length eyepiece?  (This is why we have an assortment of different focal lengths.)