Hertzsprung gap

The Hertzsprung- gap is a region in the Hertzsprung -Russell diagram, in which only a very small number located on stars. The Hertzsprung- gap lies above the main sequence between spectral types mid- A to late F. The gap is produced both by the short stay of stars in this region of the color-magnitude diagram as well as by this required mass of stars that are more than four must be solar masses. After the initial mass function of only a few tenths of a percent of all stars have the necessary mass to take a developmental path through the Hertzsprung gap.

The Hertzsprung- gap exists only for stars of Population I, as the horizontal branch is located at metal -poor stars of Population II within the gap.

Swell

• Helmut Scheffler, Hans Elsässer: physics of stars and the sun. 2nd revised and enlarged edition. BI Publisher Science, Mannheim, 1990, ISBN 3-411-14172-7.
• A. Unsold, B. Baschek: The new cosmos: Introduction to Astronomy and Astrophysics. 7th revised and enlarged edition edition. Springer Verlag, Berlin 2006, ISBN 978-3540421771.

• Stellar physics
• Observational astronomy