WR 30a was discovered in a photographic survey in the constellation Carina using the Curtis-Schmidt Telescope at the Cerro Tololo Inter-American Observatory.

[13] Another 1984 study noted dilution of some emission lines, and suggested the presence of a binary companion of approximate spectral type O4.

A WO5 class was temporarily assigned to account for the unusually low excitation,[15] but it was confirmed at WO4 when quantitative criteria for the WO sub-classes were defined.

Some components of the spectrum are produced by stellar winds not moving at orbital velocity with the stars.

[4] The stars do not eclipse each other, but they are deformed by the gravity and show small brightness variations during the orbit.

The shock front where the winds collide is approximately a cone around the O star with a half angle of 50°.

[17] WR 30a shows regular and continuous brightness variations of 0.02 magnitudes with a stable period of 4.6 days.

Very strong stellar winds, with a terminal velocity of 4,500 kilometers per second are causing WR 30a A to lose over 10−5 M☉/year.

Some helium lines and nitrogen emission is detected in the spectrum, indicating the mixing of fusion products to the surface and a strong stellar wind.

Researchers are careful to avoid ambiguity about the star defined as the primary and typically refer to the components as "WR" and "O".

[20] Single-star evolutionary models of the WO component of WR 30a suggest it started life as a rapidly rotating 120 M☉ star which has now lost over 90% of its mass.