[4] The stellar wind from this supergiant is expelling matter from the star at the rate of 1.55 × 10−6 solar masses per year, or roughly the equivalent to the Sun's mass every 640,000 years.
ζ2 is a mere 135 light-years distant and much less luminous in real terms.
ζ1 Scorpii can also be distinguished from ζ2, due to the latter's orange hue especially in long-exposure photographs.
ζ1 Scorpii is a candidate luminous blue variable (cLBV), a star with the luminosity and spectral appearance of an LBV, but one that has not yet shown the characteristic types of variability.
[5] It has been classified as dormant or ex-S Doradus variable, an older name for LBVs.