Introduction

This week, we’ll evaluate four images, three images of the galaxy Centaurus A, one from the European Southern Observatory, one from the Anglo-Australian Observatory, and one from Hubble, plus one of your own of the galaxy NGC 5055 from Exploration 6.

As always, this Exploration should take about an hour to complete, the equivalent of one class period. If you need help, plan to attend one of the free help sessions. The schedule of help sessions is in the syllabus.

Learning Goals:

Students should be able to…

• Recognize significant features in astronomical images.
• Recognize what design choices contribute to an image’s aesthetic appeal.
• Describe the scientific content of an astronomical image.

What to Do:

Compare and contrast the three images of Centaurus A, applying the aesthetic principles discussed in class this week and described in Chapter 12. Identify and describe the design choices that contribute to the images’ visual appeal.

ESO Image	AAO Image	Hubble Image

How do the visual aspects of three images of Centaurus A (such as colors, hue, placement, resolution, etc.) impact how you view this galaxy?

Use the internet to search for information about the astronomical object and the imaging process, and describe briefly how the images convey what we know about the Galaxy.

1. What type of astronomical object is Centaurus A?
2. What is the distance to Centaurus A and is that considered near or far in astronomical terms? Is Centaurus A within or outside of the Milky Way galaxy?
3. What scientific information do the images convey about Centaurus A?
4. How does the choice of broad and/or narrowband filters help to convey scientific information about Centaurus A?

Now consider one of your own images from Exploration 6. Evaluate your image using the principles discussed in class this week and described in Chapter 12.

Submit your responses to the questions below using the assignment worksheet, and submit it via this Canvas assignment.