Checked content



Cscr-featured.svgSound-icon-empty.svgThis is a featured picture on the English language Wikipedia ( Featured pictures) and is considered one of the finest images.

If you think this file should be featured on Wikimedia Commons as well, feel free to nominate it.
If you have an image of similar quality that can be published under a suitable copyright license, be sure to upload it, tag it, and nominate it.

Description Tycho's Supernova Remnant. In 1572, the Danish astronomer Tycho Brahe observed and studied the explosion of a star that became known as Tycho's supernova. More than four centuries later, Chandra's image of the supernova remnant shows an expanding bubble of multimillion degree debris (green and red) inside a more rapidly moving shell of extremely high energy electrons (filamentary blue). As a huge ball of exploding plasma, it was Irving Langmuir who coined the name plasma because of its similarity to blood plasma, and Hannes Alfvén who noted its cellular nature. The filamentary blue outer shell of X-ray emitting high-speed electrons is also a characteristic of plasmas. This is a false-colour x-ray image in which the energy levels (in keV) of the x-rays have been assigned a colours as follows: Red 0.95-1.26 keV, Green 1.63-2.26 keV, Blue 4.1-6.1 keV. All x-rays images must use processed colours since x-rays (as are radio waves, infra-red) are invisible to the human eye. But they are not invisible to suitable equipment, such as x-ray telescopes. The red and green bands highlight the expanding cloud of plasma with temperatures in the millions of degrees.
Date September 2005
Author NASA/CXC/Rutgers/J.Warren & J.Hughes et al.


Public domain This file is in the public domain because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.)
NASA logo.svg
  • Use of NASA logos, insignia and emblems are restricted per US law 14 CFR 1221.
  • The NASA website hosts a large number of images from the Soviet/ Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
  • Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the STScI. See also {{ PD-Hubble}} and {{ Cc-Hubble}}.
  • The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use.
  • Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted.

Old file history

Originally uploaded on the En-Wiki by en:User:Iantresman 12:40, 23 September 2005

The following pages on Schools Wikipedia link to this image (list may be incomplete):

What is Schools Wikipedia?

Wikipedia for Schools was collected by SOS Children's Villages. SOS Children works in 133 countries and territories across the globe, helps more than 62,000 children, and reaches over 2 million people in total. We have helped children in Africa for many years - you can help too...