An overview of the Chandra mission and goals, Chandra's namesake, top 10 facts.
Classroom activities, printable materials, interactive games & more.
Overview of X-ray Astronomy and X-ray sources: black holes to galaxy clusters.
All Chandra images released to the public listed by date & by category
Current Chandra press releases, status reports, interviews & biographies.
A collection of multimedia, illustrations & animations, a glossary, FAQ & more.
A collection of illustrations, animations and video.
Chandra discoveries in an audio/video format.
Q&A: Normal Stars, White Dwarf Stars, and Star Clusters

Q:
Orion Nebula
Orion Nebula
The X-ray image of Orion Nebula seems to have a large cross in its center, as if it was formed by 4 quadrants. Why is that?

A:
The cross in the image is an instrumental artifact due to the arrangement of the CCD chips in the imaging array of the ACIS detector. See http://chandra.harvard.edu/about/science_instruments2.html Some images do not show this effect because the image is entirely on one chip.

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