8B30.20 - HR Diagram

Credit for the picture and explanation: ESO ( European Southern Observatory).
Credit for the picture and explanation: ESO ( European Southern Observatory).
Code Number:
8B30.20
Demo Title:
HR Diagram
Condition:
Good
Area of Study:
Stellar Astronomy
Procedure:

Credit for the picture and explanation:  ESO ( European Southern Observatory).  

In the Hertzprung-Russell diagram the temperatures of stars are plotted against their luminosities.  The position of a star in the diagram provides information about its present stage and its mass.  Stars that burn hydrogen into helium lie on the diagonal branch, the so-called main sequence.  Red dwarfs like AB Doradus C lie in the cool and faint corner.  AB Dor C has itself a temperature of about 3,000 degrees and a luminosity which is 0.2% that of the Sun.  When a star exhausts all the hydrogen, it leaves the main sequence and becomes a red giant or a supergiant, depending on its mass (AB Doradus C will never leave the main sequence since it burns so little hydrogen).  Stars with the mass of the Sun which have burnt all their fuel evolve finally into a white dwarf (left low corner).

References:
  • H. Hauptmann, F. Herrmannm and K. Schmidt, "The Transformation of a Main Sequence Star into a Red-Giant Start in the Core-and Shell Model", TPT, Vol. 68, # 5, May 2000, p. 421.
  • Christopher L. Mulliss, "Teaching the Main Sequence", TPT, Vol. 34, # 6, Sept. 1996, p. 327.
  • Emilia P. Belserene, "Response", TPT, Vol. 27, # 4, April 1989, p. 231. 
  • David L. Mott, "Aging Stars", TPT, Vol. 27, # 4, April 1989, p. 231. 
  • Emilia Pisani Belserene, "Can We Watch the Stars Grow Older?", TPT, Vol. 25, # 7, Oct. 1987, p. 420.
  • Henry Albers, "It's the Temperature, Not the Composition", TPT, Vol. 18, # 1, Jan. 1980, p. 10.
  • Claudine Carlton, "Stellar Evolution and Cosmology in High School Physics", TPT, Vol. 17, # 7, Oct. 1979, p. 460. 
  • Robert T. Deck, "Comments on 'Why is the Sun So Large?'", AJP, Vol. 74, # 1, Oct. 2006, p. 10.
  • D. J. Mullan, "Why is the Sun So Large?", AJP, Vol. 74, # 1, Jan. 2006, p. 10.
  • H. Hauptmann, F. Herrmann, K. Schmidt, "The Transformation of a Main Sequence Star Into a Red - Giant Star in the Core - Shell - Model", AJP, Vol. 68, # 5, May 2000, p. 421.
  • M. Maercker et al., "Deciphering a Star's Spiral Shell", Back Scatter, Physics Today, Dec. 2012, p. 92.
  • D. Tattersfield, "7.25, The Hertzsprung-Russell Diagram", Projects and Demonstrations in Astronomy, p. 171.
  • Janice VanCleave, "Demonstrate Why Stars of the Same Luminosity Can Appear to Be of Different Brightness", Super Science Challenges, p. 15.
  • Janice VanCleave, "Winter Colors", Constellations for Every Kid, p. 208.

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