Overview: Galaxy Centaurus A

of "Lithograph: Galaxy Centaurus A"
Lithograph: Galaxy Centaurus A (PDF)
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This image from the Hubble Space Telescope shows a dark lane of dust, believed to be the remains of a smaller spiral galaxy that collided with the larger elliptical galaxy millions of years ago. Astronomers believe Centaurus A hosts a supermassive black hole that is feeding on the fresh remains of the smaller spiral galaxy. Background information and another image provide details about the black hole and the star birth triggered by the collision.
Format(s) available: PDF
Grades: 6-12, but the material can be adapted for use in other grades at the teacher's discretion
How to use it in the classroom

Teachers can use Lithograph: Galaxy Centaurus A as:

An engagement tool in an inquiry-based lesson. Have students study the image side of the lithograph. Ask them to write down three to five questions they have about the image. When the students are finished, their questions can be used in a variety of ways:

• Ask students to find the answers to their questions by reading the back of the lithograph and/or the related materials listed below.

• Have students exchange papers so that each student has someone else's questions. Then have them find the answers to the other students' questions by reading the back of the lithograph and/or the related materials listed below.

• Gather the questions into a list by asking students to volunteer to read their questions while you or another student records them on the board or overhead. Ask students to raise their hands if they had the same or a similar question. Count the number of hands raised and record this number next to the question. Once all the student questions have been added to the list, have students search for the answers to their questions in the text on the back of the lithograph. When they complete that task, ask them to decide if each of their questions was answered completely, answered partially, or not answered at all. Go through the original list and place an "A" in front of the questions that were answered completely, a "P" for those that were partially answered, and an "N" for those that were not answered at all. Determine if the most commonly asked questions were also completely answered. Encourage students to do further research to find answers to the unanswered questions.

A content reading tool. Have students read the back of the lithograph and then write a quiz for the class.

A component in a history of science activity. Students can use Lithograph: Galaxy Centaurus A along with Tales of … Key events in the history of Centaurus A to look at how our view of the galaxy changed as our technology improved. After reading the lithograph and the article, have students list the changes in technology that led astronomers to conclude that a supermassive black hole is in the center of Centaurus A.

Related materials

Tales of … Key events in the history of Centaurus A

HubbleSite press release: "Hubble Provides Multiple Views of How to Feed a Black Hole"

See the Galaxies section on "Teaching tools" page.

Overview: Galaxy Centaurus A