First results on strangeness production from the ANKE facility
ANKE is a second generation experimental facility at the internal beam of the accelerator COSY at the Forschungszentrum Julich (Germany). It has recently (May 1998) been installed in the ring, commissioned and immediately after this been exploited for first experiments. Using circulating beams of protons with energies between 1.0 and 2.3 GeV, sub- and near threshold production of K+ mesons in collisions with carbon-strip targets has been investigated. The detection system of ANKE used for the first measurements is capable of detecting positively charged ejectiles in the momentum range between about 100 and 600 MeV/c. In particular, it has been optimized for K+ identification in the presence of an intense background of protons and pions. The final results of the experiments (cross sections and momentum spectra) will be used to obtain more detailed information on the subthreshold production mechanism.

title: Measurement of Subthreshold K+ Production in pA Collisions with ANKE

title: Vector and tensor analysing powers in deuteron-proton breakup reactions at intermediate energies
abstract: Vector and tensor analysing powers of the d → p → ( p p ) n (charge-exchange) and d → p → ( p n ) p (non-charge-exchange) breakup reactions have been measured with the ANKE spectrometer at the COSY ring at a deuteron beam energy of 1170 MeV for small momentum transfers to the low excitation energy ( p p ) or ( p n ) systems. A quantitative understanding of the values of A x x and A y y for the charge-exchange reaction is provided by impulse approximation calculations. The data suggest that spin-flip isospin-flip transitions, which dominate the charge-exchange breakup of the deuteron, are also important in the non-charge-exchange reaction.

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: Inclusive K+-meson production in proton-nucleus interactions
abstract: The production of K+-mesons in pA (A = D, C, Cu, Ag, Au) collisions has been investigated at the COoler SYnchrotron COSY-Jülich for beam energies Tp = 1.0-2.3 GeV. Double differential inclusive pC cross-sections at forward angles ϑ{K^+} < 12° as well as the target mass dependence of the K+ momentum spectra have been measured with the ANKE spectrometer. Far below the free NN threshold at TNN = 1.58 GeV the spectra reveal a high degree of collectivity in the target nucleus. From the target mass dependence of the cross-sections at higher energies, the repulsive in-medium potential of the K+-mesons can be deduced. Using pN cross-section parameterisations from the literature and our measured pD data we derive a cross-section ratio σ(pn↦K+X)/σ(pp↦K+X) ∼ (3-4).

title: THE FORWARD DETECTOR OF THE ANKE SPECTROMETER. SCINTILLATION AND CHERENKOV HODOSCOPES
abstract: Central Institute for Nuclear Research, Rossendorf, GermanyThe scintillation and Cherenkov counter system of the forward detector of ANKE, magnetic spec-trometer at the internal beam of the accelerator COSY in Jeulich, is described. The timing and amplitudecharacteristics are presented as well as the capabilities to select physical processes of interest.¶¨¸O¢ ¥E¸O ¸¨¸E¥³ ¸I¨´E¨²²O I¨µ´´OI ¨ I¥·¥´±µ¢¸±¨I ¸I¥EI¨±µ¢ ¶¥·¥¤´¥£µ ¤¥E¥±Eµ· ANKE, ³ £´¨E´µ£µ ¸¶¥±E·µ³¥E· ´ ¢´EE·¥´´¥³ ¶EI±¥ E¸±µ·¨E¥²O COSY ¢ ²¨I¥. ·¨¢¥¤¥´O¨I ¢·¥³¥´´O¥ ¨ ³¶²¨EE¤´O¥ I · ±E¥·¨¸E¨±¨, E ±¦¥ ¢µ§³µ¦´µ¸E¨ ¨I ¶·¨³¥´¥´¨O ¤²O ¢O¤¥²¥´¨O¨´E¥·¥¸EOÐ¨I E¨§¨I¥¸±¨I ¶·µI¥¸¸µ¢.

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: 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: Constraining the role of star cluster mergers in nuclear cluster formation: simulations confront integral-field data
abstract: We present observations and dynamical models of the stellar nuclear clusters (NCs) at the centres of NGC 4244 and M33. We then compare these to an extensive set of simulations testing the importance of purely stellar dynamical mergers on the formation and growth of NCs. Mergers of star clusters are able to produce a wide variety of observed properties, including densities, structural scaling relations, shapes (including the presence of young discs) and even rapid rotation. None the less, difficulties remain, most notably that the second-order kinematic moment inline image of the models is too centrally peaked to match observations. This can be partially remedied by the merger of star clusters on to a pre-existing nuclear disc, but the line-of-sight velocity V is still more slowly rising than in NGC 4244. Our results therefore suggest that purely stellar dynamical mergers cannot form NCs and that gas dissipation is a necessary ingredient for at least ∼50 per cent of a NC’s mass. The negative vertical anisotropy found in NGC 4244, however, requires at least 10 per cent of the mass to have been accreted as stars, since gas dissipation and in situ star formation leads to positive vertical anisotropy.

title: Transiting exoplanets from the CoRoT space mission XIV. CoRoT-11b: a transiting massive "hot-Jupiter" in a prograde orbit around a rapidly rotating F-type star
abstract: The CoRoT  exoplanet science team announces the discovery of CoRoT-11b, a fairly massive hot-Jupiter transiting a V  = 12.9 mag F6 dwarf star ( M ∗  = 1.27 ± 0.05  M ⊙ , R ∗  = 1.37 ± 0.03  R ⊙ , T eff  = 6440 ± 120 K), with an orbital period of P  = 2.994329 ± 0.000011 days and semi-major axis a  = 0.0436 ± 0.005 AU. The detection of part of the radial velocity anomaly caused by the Rossiter-McLaughlin effect shows that the transit-like events detected by CoRoT  are caused by a planet-sized transiting object in a prograde orbit. The relatively high projected rotational velocity of the star ( v sin i ⋆  = 40 ± 5 km s -1 ) places CoRoT-11 among the most rapidly rotating planet host stars discovered so far. With a planetary mass of M p   = 2.33 ± 0.34  M Jup  and radius R p   = 1.43 ± 0.03  R Jup , the resulting mean density of CoRoT-11b ( ρ p  = 0.99 ± 0.15 g/cm 3 ) can be explained with a model for an inflated hydrogen-planet with a solar composition and a high level of energy dissipation in its interior.