We present precise stellar radial velocity measurements of \gamma Dra taken from 2003 to 2017 .
The data from 2003 to 2011 show coherent , long-lived variations with a period of 702 d. These variations are consistent with the presence of a planetary companion having m sin i = 10.7 M _ { Jup } whose orbital properties are typical for giant planets found around evolved stars .
An analysis of the Hipparcos photometry , Ca II S-index measurements , and measurements of the spectral line shapes during this time show no variations with the radial velocity of the planet which seems to “ confirm ” the presence of the planet .
However , radial velocity measurements taken 2011 – 2017 seem to refute this .
From 2011 to 2013 the radial velocity variations virtually disappear only to return in 2014 , but with a noticeable phase shift .
The total radial velocity variations are consistent either with amplitude variations on timescales of \approx 10.6 yr , or the beating effect between two periods of 666 d and 801 d. It seems unlikely that both these signals stem from a two-planet system .
A simple dynamical analysis indicates that there is only a 1–2 % chance that the two-planet is stable .
Rather , we suggest that this multi-periodic behavior may represent a new form of stellar variability , possibly related to oscillatory convective modes .
If such intrinsic stellar variability is common around K giant stars and is attributed to planetary companions , then the planet occurrence rate among these stars may be significantly lower than thought .