Habitable zone, or circumstellar habitable zone (CHZ) is a term in astronomy and astrobiology, that refers to the range of orbits around a star which are based on Earth's position to the Sun. Calculations for a star system's CHZ is contingent to the amount of radiant energy Earth receives from the Sun in the Solar System, to hypothetically support a planetary surface with liquid water and sufficient atmospheric pressure for life.[1][2][3][4][5]


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  4. Kopparapu, Ravi Kumar (2013). "A revised estimate of the occurrence rate of terrestrial planets in the habitable zones around kepler m-dwarfs". The Astrophysical Journal Letters 767 (1): L8. doi:10.1088/2041-8205/767/1/L8. Bibcode2013ApJ...767L...8K. 
  5. Cruz, Maria; Coontz, Robert (2013). "Exoplanets - Introduction to Special Issue". Science 340 (6132): 565. doi:10.1126/science.340.6132.565. Retrieved 18 May 2013.