RANDY L.
PHELPS
This is the Ground-Based
Observatories Module
For this assignment, please look through the
"lecture" notes for "Ground-Based Observatories". These notes contain the
material, in condensed form, that I will expect you to become familiar with. By
that, for this assignment, I simply mean to become familiar with the observatories I
outline in the notes (notice, there are few words!). To become familiar with them,
you will need to explore the links I have provided. You will find that some of these
links are somewhat technical, while some are good at catering to a general audience.
I am aware of that, but do your best.
Upon completing
this assignment, you should be comfortable with the following material:
- The two basic types of telescopes: refracting and
reflecting. The advantages/disadvantages of each.
- The two important concepts that drive telescope
design are "light gathering power" and "resolution".
- The California connection to astronomy. What
are the major astronomical observatories in California?
- Interferometers/arrays: What are these telescopes,
why are they useful, and what are their properties?
Upon completing
this assignment, you should be able to answer these, and similar questions
General
Concepts
- Who invented the refracting telescope?
- Who first used the refracting telescope for
astronomical observations?
- Who devised the first practical reflecting
telescopes?
- Why locate an observatory in the southern
hemisphere?
Applications
- Which telescope has the higher light gathering
power, the Keck 10-meter, or the 5-meter Palomar telescope?
- Which telescope has the higher light gathering
power, the Keck 10-meter, or a 10-meter radio telescope?
- Which telescope has the higher resolution, the
Keck 10-meter, or the 5-meter Palomar telescope?
- Which telescope has the higher resolution, the
Keck 10-meter, or a 10-meter radio telescope?
- Refracting telescopes use lenses as the primary
optical element. The lens must be supported on the side. Why does this limit
the size of the largest refracting telescope to about 1-meter in diameter?
- Why are most modern, large telescopes of the
reflecting variety?
- Two radio telescopes in an array, that have dishes
with diameters of 5 meters, are separated by a distance of 100 meters. The collecting area
of a single telescope is equal to 19.6 square-meters. The Goldstone, CA radio
telescope has a diameter of 30 meters, or a collecting area of 706.8 square meters.
A. Is the resolution of the array equal to that of a 10-meter telescope, a
5-meter telescope or a 100-meter telescope? B. Is the resolution of the array
better than, or worse than the Goldstone telescope? C. Which can see
fainter objects, the array or the Goldstone telescope?
These questions, and similar ones, will form the basis of the exam
material for this section of the course. If you have problems with the material,
please see me. If you are unable to answer some of the questions, I will help
you before the date specified on the syllabus, provided you show me the results of your
inquiry into the material.
That is, you must provide me the answers you
we able to obtain for all questions, including your attempts at problem questions, before
I will help you with any of them!
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