ZrO band bând-e ZrO Fr.: bande ZrO Any of the three → absorption bands due to the molecule → zirconium oxide present in the blue and visual spectral regions → S-type stars. The bands are centered on the wavelengths 4614, 5551, and 6468 Å. → zirconium oxide; → band. |
ZZ Ceti star setâre-ye ZZ Ketus Fr.: étoile de type ZZ Ceti A member of a class of non-radially pulsating stas that change their brightnesses with periods from 30 seconds to 25 minutes and amplitudes from 0.001 to 0.2 mag in V. Their location on the → Hertzsprung-Russell diagram identifies them as → white dwarf stars that have entered the → instability strip as they evolve along the white dwarf track. |