Of all things in Nature, astronomical objects make up some of the most gorgeous photographs ever made. The project is designed to allow students to explore creating their own photographs, or images, from the beginning to the end of the process. The beginning of the process is choosing an object to image. This introductory activity will allow you to able to identify basic types of deep sky objects based upon appearance in an image.
When astronomers first began to look at the sky with telescopes, they found many types of objects visible that they could not see with the naked eye. As they began to classify and describe these 'deep sky objects' (objects in space outside our solar system), it was clear that they could be grouped into certain categories based upon their appearance. The names that were given to these different groups of objects are descriptive of their appearance. For example, Planetary Nebulae were so named because they appear quite round, like a planet, and are fuzzy and diffuse like a cloud (nebula). One of the most famous catalogs of these deep sky objects was created by Charles Messier. In this activity, you will browse an electronic version of this venerable catalog to gain a n appreciation for the appearance of these objects. In particular, you should focus on the general appearance of each different TYPE of object and be able to distinguish the different types of objects from images.
1. Go To: http://www.seds.org/messier
2. Spend a few moments reading about Charles Messier and his catalog. Consider his purpose in creating this catalog and why it is still used today.
3. Click on the link: 'Look at Nebula.' You will see a complete list of Messier's objects, grouped according to category or type. Browse through several examples of each type of object such that you can identify these types in any image. You should be able to describe the appearance of Planetary Nebulae, Diffuse Nebulae, Open Star Clusters, Globular Star Clusters, Spiral Galaxies, and Elliptical Galaxies.
4. Students should choose the type of object they would like as a subject in creating their own True Color image. They should explore the SEDS site and other resources to familiarize themselves with the make-up of their chosen object.
5. Begin a Collaboratory work area in which students post their choice for type of object to image and a paragraph discussing what their object is.
Students may discuss their hints and tips for identifying deep sky objects. Questions to consider include: telling a planetary nebula from a diffuse nebula, an open cluster from a globular cluster, or an elliptical galaxy from a globular cluster?