BERYLIUM Be      Z = 14

This element was isolated independently by F. Woehler in Berlin and by A. Bussy in Paris in 1828. The name comes from the gem beryl, in Greek beryllos.

Ionization energies

BeI 9.3 eV, BeII 18.2 eV, BeIII 153.9 eV.

Absorption lines of BeI

The equivalent width of BeI 3321(1) in the sun is 0.008 Å.

Absorption lines of BeII

Table 1: Equivalent widths of BeII 3130(1) (resonance lane)

Group V III

F 0 0.043  
F 5 0.083  
G 0 0.100  
S 0.085  
K 0   0.035

Source: The stellar data are from Boesgaard (1976b).

BeII (the 3130 line) appears in A-type stars, increases up to G-type stars and decreases thereafter.

Behavior in non-normal stars

Sadakane et al. (1985) found a large range of Be strengths in Bp stars of the Hg-Mn subgroup (up to W(3130) = 0.38) and in Ap stars of the Cr-Eu-Sr subgroup. In late Ap stars Gerbaldi et al. (1986) found no strengthening of Bell.

Figure 4

Boesgaard (1976b) remarks that, in late type F dwarfs, there exists also a 'gap' like the Li gap. Such a gap is, however, absent in the Hyades (Boesgaard and Budge 1989). Stars that are deficient in Be are also deficient in Li (Boesgaard and Lavery 1986).

Rebolo (1991) and Ryan et al. (1992) found that, in metal-weak stars, Be is weakened with respect to Fe, but that it is not absent. Spite (1992), from an analysis of halo dwarfs, finds a positive correlation between Be and Fe/H.


Be has six isotopes. The more important are Be10 with a half life of 2.7 million years and the stable Be9. Apparently no short-lived isotope exists in stars (Boesgaard 1976a).

Ryan et al. (1992) analyzed the presence of Be9 in four weak-lined dwarfs. They found that the deficiency in Be9 accompanies that of other metals. Furthermore the deficiency of Be is not as uniform as that of the neighboring light elements like Li7.

Be is more stable than Li; it burns at 3.5 × 105 instead of 2 × 106 K and both are less stable than B.


Be is produced mostly by cosmic ray spallation but a small amount is (or may be) primeval.

Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.