Title: Week 7 Writing Assignment
Course: ASTRON103: The Evolving Universe: Stars, Galaxies, and Cosmology (001) DHH SU18 > Section: Week 7

Personal Tuning Fork

Edwin Hubble devised a tuning fork diagram to classify galaxies based on their appearances and shapes. (The Astronomy textbook doesn't explicitly describe Hubble's diagram as a tuning fork, but based on the diagram's resemblance to the musical device, this is the name that all astronomers use to refer to it. See DK's whiteboard presentation for more information.)

Today we still use Hubble's classification system to differentiate between different types of galaxies. For this assignment, you will construct your own visual tuning fork featuring real images of galaxies, by following a provided template.

Tasks

Research the types of galaxies that make up each segment of the Hubble tuning fork. Consult the template (see below) and ensure you know what type of galaxy each empty slot will need to be complete. You need a total of 7 galaxy types (E0, E3, E7, Sa, Sc, SBa, SBc).

Then, use the resources listed below, or your own Internet searches, to find a real image of each of these 7 types of galaxy. For each galaxy, insert the galaxy image into the tuning fork template, and label the image with the following information:

1. The name of the galaxy
2. The type of galaxy in the Hubble tuning fork
3. The wavelength the image was taken at
4. The telescope the image was taken from

In a separate document from the tuning fork diagram, write up some basic information about each galaxy you chose, and explain why it fits in its position in the diagram.

Resources

The tuning fork template is available as a google doc presentation at this link: https://docs.google.com/presentation/d/1LCJlXDajxwMYr0KmOkYbTT2gwPVHilUWXaQSCgGBcaA/edit?usp=sharing

You are also welcome to make your own version so long as it still has the same information - feel free to get creative!

Some places to get you started for images of galaxies:

- NASA APOD: https://apod.nasa.gov/apod/archivepix.html
- Space Telescope Images: https://www.spacetelescope.org/images/
- Galaxies Archive: https://www.spacetelescope.org/images/archive/category/galaxies/

Write Up

Your final write-up should be 1–2 pages in length (around 800 words), uploaded as a Microsoft Word (.doc, .docx) or Portable Document Format (.pdf) file.  You must incorporate all of the points mentioned above in your written piece for full credit. You may (and are encouraged to) expand your piece to cover any other topics or issues you find interesting, but please limit the length to 2 pages. You must also submit your completed Hubble Tuning Fork following the provided template along with the write-up.