FIG. 1 H-R diagrams of late-type evolved stars.
That is, it belonged to a group of stars that fall upon a roughly horizontal line on the H-R diagram.
(This is a track leading to the upper-right corner of the H-R diagram.)
By measuring the properties from a star's spectrum, the position of a main sequence star on the H-R diagram can be found.
Metal-rich helium-fusing stars instead lie on the so-called red clump in the H-R diagram.
This term means that the luminosity of the star will stay relatively stable while the effective temperature increases, effectively migrating horizontally across the H-R diagram.
By the late 40's Kuiper succeeded in establishing "H-R diagram" as the standard nomenclature.
There is an apparent X-ray "dividing line" in the H-R diagram among the giant stars as they cross from the main sequence to become red giants.
This ends the protostellar phase and begins the star's main sequence phase on the H-R diagram.
The H-R diagram can also be used by scientists to roughly measure how far away a star cluster is from Earth.
Słownik astronomiczny
