TELESCOPE EXERCISES

Fill in the missing quantities in the tables for the telescopes using the information supplied. Find Light Gathering Power with respect to the human eye and angular resolutions in seconds of arc.

TABLE 1: JEFF’S TELESCOPE

DIAMETER	10 inches
FOCAL LENGTH	900mm
LIGHT GATHERING
THEOR ANG RESOL

EYEPIECES	10mm	15mm	20mm	30mm
Magnification

TABLE 2: BOB’S TELESCOPE

DIAMETER	3 inches
FOCAL LENGTH	1200mm
LIGHT GATHERING
THEOR ANG RESOL

EYEPIECES	5mm	15mm	20mm	30mm
Magnification

THE NEXT FEW QUESTIONS PERTAIN TO JEFF AND BOB’S TELESCOPES

1. Two stars are separated by 1.0”. Will Jeff see two stars? Will Bob see two stars?

2. Do any of Jeff’s eyepieces produce magnifications outside the limits? Do any of Bobs? If so, which ones?

3. Consider the real situation of Jeff living on the earth with his telescope. If Jeff were to purchase a 20 inch diameter telescope to replace his 10 inch diameter telescope, would he be able to view fainter objects? Would he be able to see more details? Explain.

GENERAL REVIEW QUESTIONS AND EXERCISES

4. How much more or less light gathering power does a 12 inch telescope have than a 4 inch telescope?

5. How much smaller or larger angular resolution does a 12 inch telescope have than a 4 inch telescope?

6. Which shows more detail a telescope with a resolution of 10” or a telescope with a resolution of 6”?

7. If you buy a telescope with a focal length of 1200mm and a 6 inch diameter objective. What focal length of eyepiece would be needed to provide the maximum practical magnification for this telescope?