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Centaurus A

Centaurus A, Cen A, NGC 5128, Caldwell 77


This galaxy has long been considered an example of an elliptical galaxy disrupted by a recent collision with a smaller-companion spiral galaxy. The black hole in the active nucleus is so dense it contains the mass of about 55 million suns, compacted into a small region of space not much larger than our solar system.


Found in the Centaurus constellation, southern celestial hemisphere

Distance from Earth

Approximately 11 million light-years away

The warped disk of gas and dust is evidence for a past galaxy collision. Resulting shock waves cause hydrogen gas clouds to compress, triggering new star formation, seen in the red patches in this Hubble close-up.

Enlarge Image


"Fast Facts: Centaurus A" is a table that lists the name, description, location, size, and distance of the galaxy from Earth. An image of the galaxy is included.

Printer-friendly web page
Adaptable, at teacher's discretion
How to use in the classroom

Use this resource as:

A source of information. Read the table to find out about this object.

A mapping activity. Locate the galaxy's associated constellation on a star map.

A large-number recognition activity. Have students study this table and other galaxy Fast Fact tables.  Students can order objects based upon their distances from Earth.

An inquiry tool. Have students write down questions they would like answered about the image and the information in the Fast Facts table.

An engagement tool. Involve students in a discussion.

Related materials

HubbleSite press release: "Firestorm of Star Birth in the Active Galaxy Centaurus A"

Amazing Space resources by topic: Galaxies

Amazing Space resources by topic: Black holes