HD 93403 is a spectroscopic binary containing two highly luminous hot blue stars.
It appears to have spectral type O5.5III, but this is composed of two spectra from a blue supergiant and blue main sequence star of spectral type O5.5I and O7V respectively.
The binary is shedding mass at the high rate of 0.0005 M☉ per year.
[3] HD 93403 exhibits the Struve-Sahade effect, where the strength of the spectral lines of the individual components varies during the orbit.
It also has colliding stellar winds that produce variable x-ray[6] and non-thermal radio emission.