Astronomy 203, Fall 2003
Olszewski and Rigby
Homework 4

DUE DATE: Nov 18 at the beginning of class.
          No late homework accepted.

Please TYPE short but complete answers to each of the following on
a separate piece of paper.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
We probably told you in class that the discovery of optical pulses
from the pulsar in the Crab Nebula was made here in Tucson
at Steward Observatory's 36" telescope on Kitt Peak.

Go to the following website
http://www.aip.org/history/mod/

Click on "the detection of the first optical pulsar."
At the top of the page you'll see a contents window, pages 1-10.
Read each page (you can click "next" at the bottom of each page or
change the page number in the contents window).

There are also audio files recorded back in 1968, so you can hear the
words while reading the transcripts!

THEN
Answer the following questions:

1) How did Cocke and Disney point their small telescope to the right
place in the Crab Nebula?

2) What does the Doppler Effect have to do with Cocke and Disney's
first failure to detect the Crab Pulsar in the optical (explain!)?

3) After they discovered a pulse, they made an observation that
depressed them. What was it? Then they moved the telescope again and
were un-depressed. Why? (give an explanation)

4) How did they determine which of the two central stars was the pulsar?
(What did they make to help their observations)

5) Why was it important to discover the Crab Pulsar giving out large
amounts of optical light? What did it teach us that we didn't already
know (or were able to explain) from the fact that this was a radio
pulsar?