Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum
Our aim is to confirm the nature of the long period radial velocity measurements for β Gem first found by Hatzes & Cochran (1993).  We present precise stellar radial velocity measurements for the K giant star β Gem spanning over 25 years. An examination of the Ca II K emission, spectral line shapes from high resolution data ($R = 210\,000$), and Hipparcos photometry was also made to discern the true nature of the long period radial velocity variations.  The radial velocity data show that the long period, low amplitude radial velocity variations found by Hatzes & Cochran (1993) are long-lived and coherent. Furthermore, the Ca II K emission, spectral line bisectors, and Hipparcos photometry show no significant variations of these quantities with the radial velocity period. An orbital solution assuming a stellar mass of 1.7 $M_\odot$ yields a period, $P = 589.6$ days, a minimum mass of 2.3 M Jupiter , and a semi-major axis, $a = 1.6$ AU. The orbit is nearly circular ($e = 0.02$).  The data presented here confirm the planetary companion hypothesis suggested by Hatzes & Cochran (1993). β Gem is one of six intermediate mass stars known to host a sub-stellar companion and suggests that planet-formation around stars much more massive than the sun may common.

title: A substellar component orbiting the F-star 30 Arietis B
abstract: Most current radial velocity planet search programs have concentrated on stars of one solar mass. Our knowledge on the frequency of giant planets and brown dwarf companions to more massive stars is thus rather limited. In the case of solar-like stars, the frequency of short-period brown dwarf companions and very massive planets seems to be low.  Here we present evidence for a substellar companion to 30 Ari B, an F-star of 1.16 ± 0.04 $M_\odot$ that is a member of a hierarchical triple system.  The companion was detected by means of precise radial velocity measurements using the 2-m Alfred-Jensch telescope and its echelle spectrograph. An iodine absorption cell provided the wavelength reference for precise stellar radial velocity measurements.  We analyzed our radial velocity measurements and derived an orbit to the companion with period, P = 335.1 ± 2.5 days, eccentricity e = 0.289 ± 0.092, and mass function $f(m)$ = (6.1 ± 1.7)$\times$10 -7 $M_\odot$. Conclusions. We conclude that the radial velocity variations of 30 Ari B are due to a companion with m  sin  i of 9.88 ± 0.94 $M_{\mathrm{Jup}}$ that is either a massive planet or a brown dwarf. The object thus belongs to the rare class of massive planets and brown dwarfs orbiting main- sequence stars.

title: Exoplanets around G-K Giants
abstract: G and K giants are a class of radial velocity (RV) variables. One reason for this variability are planetary companions which are indicated in time series of stellar spectra. Since 2004 these spectra in the visual range were obtained with the high resolution coud\'e \'echelle spectrograph mounted on the 2m telescope of the Th\"uringer Landessternwarte Tautenburg (TLS) for a northern sample of 62 very bright K giants. In the South around 300 G and K giants were observed with HARPS mounted on the 3.6m telescope on La Silla. The TLS sample contains at least 11 stars (18 %) which show low-amplitude, long-period RV variations most likely due to planets. This percentage of planet frequency is confirmed by preliminary results of the HARPS study. Moreover the TLS survey seems to indicate that giant planets do not favour metal-rich stars, are more massive, and have longer periods than those found around solar-type host stars.

title: Planets of young stars: the TLS radial velocity survey
abstract: We report on the search for planets orbiting 46 nearby young stars performed at the State Observatory of Turingia (TLS) by means of a radial velocity survey. The aim of this program is to test the theories of formation/evolution of planetary systems. For 19(8) stars we can exclude planets with Msini > 1 MJ (5 MJ) and P < 10 days; we find 1 short period binary and 5 stars with long period RV-trend. One good young exo-planet candidate is presented.

title: Three-integral multicomponent dynamical models and simulations of the nuclear star cluster in NGC 4244
abstract: Adaptive optics observations of the flattened nuclear star cluster in the nearby edge-on spiral galaxy NGC 4244 using the Gemini near-infrared integral field spectrograph (NIFS) have revealed clear rotation. Using these kinematics plus 2MASS photometry, we construct a series of axisymmetric two-component particle dynamical models with our improved version of NMAGIC, a flexible χ2-made-to-measure code. The models consist of a nuclear cluster disc embedded within a spheroidal particle population. We find a mass for the nuclear star cluster of M = 1.6+0.5 −0.2 × 107M� within ∼42.4 pc (2 arcsec). We also explore the presence of an intermediate-mass black hole and show that models with a black hole as massive as M• = 5.0 × 105M� are consistent with the available data. Regardless of whether a black hole is present or not, the nuclear cluster is vertically anisotropic (βz < 0), as was found with earlier anisotropic Jeans models. We then use the models as initial conditions for Nbody simulations. These simulations show that the nuclear star cluster is stable against nonaxisymmetric 
perturbations. We also explore the effect of the nuclear cluster accreting star clusters at various inclinations. Accretion of a star cluster with mass 13 per cent that of the nuclear cluster is already enough to destroy the vertical anisotropy, regardless of orbital inclination.

title: Planetary companion candidates around the K giant stars 42 Draconis and HD 139 357
abstract: For the past 3 years we have been monitoring 62 K giant stars using precise stellar radial velocity (RV) measurements with the 2 m Alfred Jensch Telescope of the Thuringer Landessternwarte Tautenburg ( TLS ).  To probe the dependence of planet formation on stellar mass by finding planets around intermediate-mass giant stars.  We present high accuracy RV measurements of the K1.5 III star 42 Dra and the K4 III star HD 139357. The wavelength reference for the RV measurements was provided by an iodine absorption cell placed in the optical path of the spectrograph.  Our measurements reveal that the time series of the radial velocity of 42 Dra shows a periodic variation of 479.1 days with a semiamplitude of K  = 112.5 m s -1 . An orbital solution yields a mass function of $f(m)$ = (5.29 ± 0.62) $\times$ 10 -8  solar masses ($M_{\odot}$) and an eccentricity of e  = 0.38  ±  0.06. From our template spectra, taken without the iodine cell, we determine a metallicity of -0.46  ±  0.04 dex and a stellar mass of 0.98 ± 0.06 $M_{\odot}$ for this star. HD 139 357 shows periodic RV variations of 1125.7 days with a semiamplitude K  = 159.9 m s -1 . An orbital solution yields an eccentricity, e = 0.10 ± 0.02 and mass function, $f(m)$ = (4.79 ± 0.57) $\times$ 10 -7  $M_{\odot}$. An iron abundance of -0.13 ± 0.04 dex is obtained, and a stellar mass of 1.31 ± 0.24 $M_{\odot}$ for the parent star is derived. An analysis of the HIPPARCOS photometry as well as our H α core flux measurements reveal no variability with the radial velocity period. Keplerian motion is the most likely explanation for the observed radial velocity variations for these stars.  The K giant stars 42 Dra and HD 139 357 host extrasolar planets with “minimum masses” of 3.88 ± 0.85 Jupiter masses $M_{\mathrm{Jup}}$ and 9.76 ± 2.15 $M_{\mathrm{Jup}}$, respectively.

title: Identification of K+-mesons from subthreshold pA collisions with ANKE at COSY-Jülich
abstract: The spectrometer ANKE has been put into operation at the accelerator COSY of the Forschungszentrum Julich in spring 1998. An initial scientific goal is to study K + -production in pA collisions at subthreshold energies far below the free NN-threshold at T p =1.58 GeV. This requires the identification of K + -mesons in a background of pions and protons, about 10 6 times more intense. In this paper the sophisticated detection system and the software procedures for kaon identification are described. With the help of TOF, energy-loss and range measurements as well as the track information from wire chambers, it is possible to measure d 2 σ/ d Ω d p for deep subthreshold K + production at beam energies down to T p =1.0 GeV.

title: SOME EXPERIMENTAL TECHNIQUES AT STORAGE RINGS
abstract: Two experimental techniques that have been developed at the COoler SYnchrotron COSY-Julich are presented: (i) The energy of a stored polarized proton or deuteron beam can be precisely determined by sweeping an rf magnetic dipole or solenoid field over a spin resonance. This perturbation induces a beam depolarization, which is maximal at the spin resonance's frequency. That frequency, together with the beam revolution frequency, determines the beam's kinematic γ factor, which can thus be measured with high accuracy. Therefore, the beam energy can be determined about one order of magnitude more precisely than with conventional methods based on orbit length measurements. The technique has been used at COSY for an experiment aiming at a high-precision measurement the mass of the η meson. (ii) The repeated passage of a coasting ion beam through a thin internal target leads to a beam-energy loss and a shift of its revolution frequency. This shift is proportional to the beam-target overlap and thus allows one to measure the target thickness and hence the luminosity during the corresponding experiment. This effect has been studied quantitatively with a 2.65 GeV proton beam impinging on a hydrogen cluster-jet target at the ANKE spectrometer. After a careful error evaluation the luminosity, could be determined with an accuracy of better than 5%.

title: The dp → ppn reaction as a method to study neutron-proton charge-exchange amplitudes
abstract: AbstractThe differential cross section and deuteron analysing powers of the $$
\vec d
$$p → {pp}n charge-exchange reaction have been measured with the ANKE spectrometer at the COSY storage ring. Using a deuteron beam of energy 1170MeV, data were obtained for small momentum transfers to a {pp} system with low excitation energy. A good quantitative understanding of all the measured observables is provided by the impulse approximation using known neutron-proton amplitudes. The proof of principle achieved here for the method suggests that measurements at higher energies will provide useful information in regions where the existing np database is far less reliable.

title: A MULTISITE CAMPAIGN TO MEASURE SOLAR-LIKE OSCILLATIONS IN PROCYON. I. OBSERVATIONS, DATA REDUCTION, AND SLOW VARIATIONS
abstract: We have carried out a multisite campaign to measure oscillations in the F5 star Procyon A. We obtained high-precision velocity observations over more than three weeks with 11 telescopes, with almost continuous coverage for the central 10 days. This represents the most extensive campaign so far organized on any solar-type oscillator. We describe in detail the methods we used for processing and combining the data. These involved calculating weights for the velocity time series from the measurement uncertainties and adjusting them in order to minimize the noise level of the combined data. The time series of velocities for Procyon shows the clear signature of oscillations, with a plateau of excess power that is centered at 0.9 mHz and is broader than has been seen for other stars. The mean amplitude of the radial modes is -->38.1 ± 1.3 cm s−1 (2.0 times solar), which is consistent with previous detections from the ground and by the WIRE spacecraft, and also with the upper limit set by the MOST spacecraft. The variation of the amplitude during the observing campaign allows us to estimate the mode lifetime to be -->1.5+ 1.9−0.8 days. We also find a slow variation in the radial velocity of Procyon, with good agreement between different telescopes. These variations are remarkably similar to those seen in the Sun, and we interpret them as being due to rotational modulation from active regions on the stellar surface. The variations appear to have a period of about 10 days, which presumably equals the stellar rotation period or, perhaps, half of it. The amount of power in these slow variations indicates that the fractional area of Procyon covered by active regions is slightly higher than for the Sun.

title: A multi-site campaign to measure solar-like oscillations in Procyon. II. Mode frequencies
abstract: We have analyzed data from a multi-site campaign to observe oscillations in the F5 star Procyon. The data consist of high-precision velocities that we obtained over more than three weeks with 11 telescopes. A new method for adjusting the data weights allows us to suppress the sidelobes in the power spectrum. Stacking the power spectrum in a so-called echelle diagram reveals two clear ridges, which we identify with even and odd values of the angular degree (l = 0 and 2, and l = 1 and 3, respectively). We interpret a strong, narrow peak at 446 mu Hz that lies close to the l = 1 ridge as a mode with mixed character. We show that the frequencies of the ridge centroids and their separations are useful diagnostics for asteroseismology. In particular, variations in the large separation appear to indicate a glitch in the sound-speed profile at an acoustic depth of similar to 1000 s. We list frequencies for 55 modes extracted from the data spanning 20 radial orders, a range comparable to the best solar data, which will provide valuable constraints for theoretical models. A preliminary comparison with published models shows that the offset between observed and calculated frequencies for the radial modes is very different for Procyon than for the Sun and other cool stars. We find the mean lifetime of the modes in Procyon to be 1.29(-0.49)(+0.55) days, which is significantly shorter than the 2-4 days seen in the Sun.