[9] EZ CMa has an apparent visual magnitude which varies between 6.71 and 6.95 over a period of 3.766 days, along with changes in the spectrum.

This was interpreted as a 3.66 d orbital period with rapid apsidal precession completing a full rotation in about 100 days.

[7] The spectral type of WN4 indicates an extremely hot star, and this leads to a very high luminosity, mostly emitted as ultraviolet radiation.

[4] EZ CMa is surrounded by a faint bubble nebula, a small HII region blown by stellar winds up to 1,700 km/s and ionised by the intense UV radiation.

[6] It is likely to be a member of the very scattered open cluster Collinder 121, found around the orange supergiant ο1 CMa.