Context:11 UMi and HD 32518 belong to a sample of 62 K giant stars that has been observed since February 2004 using the 2m Alfred Jensch telescope of the Thüringer Landessternwarte ( TLS ) to measure precise radial velocities ( RVs ) .

Aims : The aim of this survey is to investigate the dependence of planet formation on the mass of the host star by searching for planetary companions around intermediate-mass giants .

Methods : An iodine absorption cell was used to obtain accurate RVs for this study .

Results : Our measurements reveal that the RVs of 11 UMi show a periodic variation of 516.22 days with a semiamplitude of K = 189.70 m s ^ { -1 } .
An orbital solution yields a mass function of f ( m ) = ( 3.608 \pm 0.441 ) \times 10 ^ { -7 } solar masses ( M _ { \odot } ) and an eccentricity of e = 0.083 \pm 0.03 .
The RV curve of HD 32518 shows sinusoidal variations with a period of 157.54 days and a semiamplitude of K = 115.83 m s ^ { -1 } .
An orbital solution yields an eccentricity , e = 0.008 \pm 0.03 and a mass function , f ( m ) = ( 2.199 \pm 0.235 ) \times 10 ^ { -8 } M _ { \odot } .
The HIPPARCOS photometry as well as our H \alpha core flux measurements reveal no variability with the RV period .
Thus , Keplerian motion is the most likely explanation for the observed RV variations for both giant stars .

Conclusions : An exoplanet with a “ minimum mass ” of m \sin i = 10.50 \pm 2.47 Jupiter masses ( M _ { \mathrm { Jup } } ) orbits the K giant 11 UMi .
The K1 III giant HD 32518 hosts a planetary companion with a “ minimum mass ” of m \sin i = 3.04 \pm 0.68 M _ { \mathrm { Jup } } in a nearly circular orbit .
These are the 4th and 5th planets published from this TLS survey .