Estimated path of the HM Pup gas stream. The phases of the observations are marked around the periphery of the dashed circle, and the corresponding observed gas velocity and direction relative to the primary star are indicated inside the circle. The orbital direction and direction of rotation of the two stars are shown by the long-dashed and short-dashed arrows, respectively. The wavelengths and velocities were adjusted, for clarity, to remove the fixed systemic velocity of 58 km s⁻¹.