  Aims. This program originated as the north pole region extension of the
established exoplanet survey using 1.8 m telescope at Bohyunsan Optical
Astronomy Observatory (BOAO). The aim of our paper is to find exoplanets in
northern circumpolar stars with a precise radial velocity (RV) survey. Methods.
We have selected about 200 northern circumpolar stars with the following
criteria: Dec. > 70 degree, 0.6 < B-V < 1.6, HIPPARCOS_scat < 0.05 magnitude,
and 5.0 < mv < 7.0. The high-resolution, fiber-fed Bohyunsan Observatory
Echelle Spectrograph (BOES) was used for the RV survey. Chromospheric
activities, the HIPPARCOS photometry, and line bisectors were analyzed to
exclude other causes for the RV variations. Results. In 2010, we started to
monitor the candidates and have completed initial screening for all stars for
the last five years. We present the detection of four new exoplanets. Stars HD
11755, HD 12648, HD 24064, and 8 UMi all show evidence for giant planets in
Keplerian motion. The companion to HD 11755 has a minimum mass of 6.5 M_Jup in
a 433-day orbit with an eccentricity of 0.19. HD 12648 is orbited by a
companion of minimum mass of 2.9 M_Jup having a period of 133 days and an
eccentricity of 0.04. Weak surface activity was suspected in HD 24064. However,
no evidence was found to be associated with the RV variations. Its companion
has a minimum mass of 9.4 M_Jup, a period of 535 days, and an eccentricity of
0.35. Finally, 8 UMi has a minimum mass of 1.5 M_Jup, a period of 93 days with
an eccentricity of 0.06.
