We report the detection of a substellar companion orbiting the intermediatemass giant star 11 Com (G8 III). Precise Doppler measurements of the star from Xinglong station and Okayama Astrophysical Observatory (OAO) revealed Keplerian velocity variations with an orbital period of 326.03±0.32 days, a semiamplitude of 302.8±2.6 m s −1 , and an eccentricity of 0.231±0.005. Adopting a stellar mass of 2.7±0.3 M ⊙ , the minimum mass of the companion is 19.4±1.5 M J , well above the deuterium burning limit, and the semimajor axis is 1.29±0.05 AU. This

Abstract.In this paper, we analyze the photospheric vector magnetograms of 286 active regions (ARs) which were observed from 1988−1996 during the 22nd solar cycle at Huairou Solar Observing Station in Beijing. Among these active regions, which are dominated by bipolar magnetic fields, 203 ARs exhibit a simple configuration of magnetic fields, while 83 ARs show a more complicated configuration of magnetic fields. When we explore the relationship between the sign of the tilt angle of magnetic polarity axis and the sign of the mean current helicity defined by < B · ( × B) >, we find that: (1) There is a negative correlation between the sign of the tilt angle and the sign of the current helicity if the tilt angle is set a positive value (0−90• ) in the northern hemisphere and a negative value (0−−90• ) in the southern hemisphere for active regions following Joy's law. In other words, about 60% of the bipolar active regions have a positive/negative tilt angle with respect to solar equator and a negative/positive current helicity in the northern/southern hemisphere. (2) In about one-third of the bipolar active regions, the tilt angle and the current helicity have the same sign in both hemispheres. They are abnormal active regions with an "abnormal chirality". These active regions are located preferentially in some longitudinal bins. (3) Most of the 62 X-ray flares larger than M-class during the 22nd solar cycle have a tendency to locate in some longitudinal bins, where active regions with "abnormal chirality" appear frequently.

Context. Active longitudes have been found in various manifestations of solar activity. The longitudinal distribution of, e.g., sunspots and solar X-ray flares shows two persistent preferred longitudes separated by roughly 180 degrees. We previously studied solar X-ray flares using an improved version of a dynamic, differentially rotating coordinate system and found enhanced rotational asymmetry and rotation parameter values that are consistent for the three classes of X-ray flares. Aims. We aim to find the optimal values of rotation parameters of active longitudes of sunspots for several different time intervals and separately for the two solar hemispheres. Methods. We perform a global study of the longitudinal location of sunspots (all sunspots and first appearance sunspots) using a refined version of a dynamic, differentially rotating coordinate system. Results. We find that the rotation parameters for sunspots are in good agreement with those obtained for X-ray flares using the same method. The improved method typically finds somewhat faster equatorial rotation with better accuracy. The improved treatment also leads to a larger non-axisymmetry. Rotation parameters for all sunspots and first appearances closely agree with each other, but nonaxisymmetry is systematically larger for all sunspots than for first appearances, suggesting that strong fields follow more closely the pattern of active longitudes. The refined method emphasizes hemispheric differences in rotation. Over the whole interval, the mean rotation in the southern hemisphere is slower than in the north. We also find significant temporal variability in the two rotation parameters over the 136-year interval. Interestingly, the long-term variations (trends and residual oscillations) in solar rotation are roughly the opposite in the northern and southern hemispheres. Conclusions. Rotation parameters vary differently with time in the northern and southern hemispheres. Both sunspots and flares strongly suggest that the northern hemisphere rotated considerably faster but the southern hemisphere slightly slower than the Carrington rotation rate during the last three solar cycles.