DV UMa is an eclipsing dwarf nova with an orbital period of \sim 2.06 h , which lies just at the bottom edge of the period gap .
To detect its orbital period changes we present 12 new mid-eclipse times by using our CCD photometric data and archival data .
Combining with the published mid-eclipse times in quiescence , spanning \sim 30 yr , the latest version of the O - C diagram was obtained and analyzed .
The best fit to those available eclipse timings shows that the orbital period of DV UMa is undergoing a cyclic oscillation with a period of 17.58 ( \pm 0.52 ) yr and an amplitude of 71.1 ( \pm 6.7 ) s. The periodic variation most likely arises from the light-travel-time effect via the presence of a circumbinary object because the required energy to drive the Applegate mechanism is too high in this system .
The mass of the unseen companion was derived as M _ { 3 } \sin { i ^ { \prime } } = 0.025 ( \pm 0.004 ) M _ { \odot } .
If the third body is in the orbital plane ( i.e . i ^ { \prime } = i = 82.9 ^ { \circ } ) of the eclipsing pair , it would match to a brown dwarf .
This hypothetical brown dwarf is orbiting its host star at a separation of \sim 8.6 AU in an eccentric orbit ( e = 0.44 ) .