IR spectroscopy of symbiotic stars. XII. V934 Her

Employing optical and infrared radial velocities spanning 29yr combined with the extensive velocities in the literature, we compute the spectroscopic orbit of the M giant in that system. We determine an orbital period of 4391d, or 12.0yr, the longest for any SyXB and far longer than the 404 day orbit commonly cited for this system in the literature.

In addition to the 12.0yr orbital period, we find a shorter period of 420 days, similar to the one previously found. Instead of orbital motion, we attribute this much shorter period to long secondary pulsation of the M3 III SRb variable. Our new orbit supports earlier work that concluded that the orbit is seen nearly pole-on, which is why X-ray pulsations associated with the NS have not been detected.