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VANADIUM V Z = 23

This element was discovered by A. del Rio in Mexico City, Mexico, in 1801 and rediscovered by G. Selfström in Sweden in 1831. The name comes from the Scandinavian goddess Vanadis.

Ionization energies
VI6.7eV,VII 14.6eV,VIII29.3 eV,VIV51.4eV,VV71.8eV,VVI 141 eV,VVII 165 eV, VVIII 191 eV.

Many faint lines of V are present in stellar spectra. In the sun, V figures in fifth place among the elements as far as the number of lines is concerned.

Absorption lines of VI

Table 1. Equivalent widths of VI
  4379(22) 5727(35)
Group V Ib V III Ib
F0 0.06 0.026(II)      
F4     0.012    
F5 0.10,0.04 0.024      
F6     0.023    
F8   0.070 0.013    
G0 0.11       0.014
G1     0.043   0.018
G2 0.11   0.035   0.035
S 0.110   0.037    
G5 0.15   0.047   0.054
G8     0.037(IV) 0.107 0.098
K0 0.24     0.123,0.170  
K2       0.163 0.204
K3       0.213 0.230
K5 0.34       0.263
M0       0.281  
M2         0.269
M2.5       0.288  

VI (for instance the lines at 4379 and 5727) appears in late A-type stars and increases toward later spectral types. A slight negative luminosity effect before type G may be present in the 4379 line.

Figure 59

Emission lines of Vl
VI lines from M.34 and 48 were observed in emission in one Mira-type variable by Grudzinska (1984).

Absorption lines of Vll

Table 2. Equivalent widths of VII
  4005(32) 5929(98)
Group V Ia V III Ib
B8   0.017      
B9 0.024        
A0 0.02 0.03,0.050      
A1 0.061        
A2 0.072,0.061 0.069(Ia)      
A3   0.115(0)      
A7 0.045        
G0         0.039
G1         0.055
G2         0.047
S 0.085   0.004    
G5         0.062
G8         0.052
K2       0.033 0.073
K3         0.089
K5         0.064,0.101

VII (for instance the lines at 4005 and 5929) appears in late B-type stars and increases toward later types. A positive luminosity effect exists.

Figure 60

Forbidden lines
VIII forbidden lines are observed in one recurrent nova Joy and Swings 1945).

Behavior in non-normal stars
V seems to behave in a manner parallel to that of Fe over the whole range of Fe abundances, and it can thus be regarded as a 'typical metal'. In globular cluster stars, V seems to be slightly overabundant with respect to iron by factors of the order of two (Wheeler et al. 1989).

Isotopes
V has two stable isotopes, V50 and V51. In the solar system they occur with 99.75% and 0.25% abundances. There exist also seven short-lived isotopes. The isotopic effect in the VO bands due to the two stable isotopes would be very small and apparently no search has been undertaken.

Origin
V50 and V51 are produced by explosive nucleosynthesis, but V50 can also be produced by the nuclear statistical equilibrium process.


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

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