Image: HRDiagram

Description: Hertzsprung-Russell diagram. A plot of luminosity (absolute magnitude) against the colour of the stars ranging from the high-temperature blue-white stars on the left side of the diagram to the low temperature red stars on the right side. "This diagram below is a plot of 22000 stars from the Hipparcos Catalogue together with 1000 low-luminosity stars (red and white dwarfs) from the Gliese Catalogue of Nearby Stars. The ordinary hydrogen-burning dwarf stars like the Sun are found in a band running from top-left to bottom-right called the Main Sequence. Giant stars form their own clump on the upper-right side of the diagram. Above them lie the much rarer bright giants and supergiants. At the lower-left is the band of white dwarfs - these are the dead cores of old stars which have no internal energy source and over billions of years slowly cool down towards the bottom-right of the diagram." Converted to png and compressed with pngcrush.
Title: HRDiagram
Credit: The Hertzsprung Russell Diagram
Author: Richard Powell
Permission: This file is licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license. You are free: to share – to copy, distribute and transmit the work to remix – to adapt the work Under the following conditions: attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). share alike – If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one. http://creativecommons.org/licenses/by-sa/2.5 CC BY-SA 2.5 Creative Commons Attribution-Share Alike 2.5 truetrue (See Copyright)
Usage Terms: Creative Commons Attribution-Share Alike 2.5
License: CC BY-SA 2.5
License Link: http://creativecommons.org/licenses/by-sa/2.5
Attribution Required?: Yes