  The spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter-McLaughlin observations; ; et al in Monthly Notices of the Royal Astronomical Society (2011), 414 We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the ... [more ▼] We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the host stars' rotation axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin orbit angles consistent with zero: {\lambda} = -4.7 \pm 4.0{\deg}, {\lambda} = 15 + 33{\deg}/-43{\deg} and {\lambda} = -9.7 +9.0{\deg}/-7.7{\deg}, respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spin-orbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, {\lambda} = -79 +4.5{\deg}/-4.3{\deg}. It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems. [less ▲] Detailed reference viewed: 7 (0 ULg) Early-type stars observed in the ESO UVES Paranal Observatory Project - III. Sub-parsec and au-scale structure in the interstellar medium; ; et al in Monthly Notices of the Royal Astronomical Society (2011), 414 UVES interstellar observations from the Paranal Observatory Project are presented for early-type stars located in the line of sight to the nearby open clusters IC 2391 (Omni Vel) and NGC 6475 (M7), with ... [more ▼] UVES interstellar observations from the Paranal Observatory Project are presented for early-type stars located in the line of sight to the nearby open clusters IC 2391 (Omni Vel) and NGC 6475 (M7), with spectroscopic resolution R˜ 80 000 and signal-to-noise ratios in the Ti II (3383 Å), Ca II K, CH[SUP]+[/SUP] (4232 Å), Na I D and K I (7698 Å) lines of several hundred. The sightlines are a mixture of cluster and non-cluster objects. A total of 22 early-type stars (A and B type) are present in our sample towards IC 2391, with 21 towards NGC 6475/M7, and enable us to probe for differences in column density on scales from ˜0.07 to 7.3 and ˜0.05 to 4.9 pc in the respective clusters. Additionally, towards Praesepe the Na I D interstellar variation only is probed towards 13 sightlines and transverse scales of ˜0.16-10.7 pc at R= 70 000. Towards IC 2391 variations are found in Ti II, Ca II K and Na I D column density in different sightlines of up to 0.7, 1.0 and 1.8 dex (excluding one star), respectively. This kind of variability correlates well with the Hipparcos parallax of the objects, and probes structure within the Local Bubble. For cluster-only objects the variations are 0.3, 0.3 and 0.5 dex, respectively. For the field of view towards NGC 6475 the corresponding maximum variations are somewhat smaller, being 0.5, 0.3, 0.8 and 1.0 dex for Ti II, Ca II K, Na I and K I, respectively, for all objects and 0.4, 0.2, 0.6 and 0.7 dex for the cluster-only objects. These are uncorrelated with parallax, and again demonstrate that Ca II K tends to be more smoothly distributed than Na I D. A few likely cluster sightlines show evidence for CH[SUP]+[/SUP] and variations in this molecular species of a factor of 10 in equivalent width over sub-pc scales. Towards Praesepe variation in interstellar Na I D is small, being a maximum of only ˜0.4 dex (including measurement errors), but with fewer sightlines studied. Overall, the scatter in the data is similar for the singly ionized species Ti II and Ca II, lending more support to the hypothesis that these two species sample similar parts of the interstellar medium (ISM). This also appears to be the case for the neutral species Na I D and K I in the one cluster studied. Finally, multiple-epoch observations from a variety of archive sources are used to search for astronomical unit (au) scale structure in the ISM towards 46 sightlines. There are tentative indications of structure on scales of tens to thousands of au for three sightlines. Future observations will confirm the veracity or otherwise of the time-variable components and others presented. Based on observations taken at UT2, Kueyen, Cerro Paranal, Chile, ESO DDT programme 265.D-5655(A), UVES Paranal Observatory Project and using FEROS on the ESO 2.2-m telescope, La Silla, Chile, programme ID 078.C-0493(A), the Observatoire de Haute Provence, France, the Pic du Midi telescope, France and the AAO archive. [less ▲] Detailed reference viewed: 3 (0 ULg)Small Scale Structure in the ISM towards IC 2391 and NGC 6475; ; et al in Haverkorn, M.; Goss, M. (Eds.) SINS - Small Ionized and Neutral Structures in the Diffuse Interstellar Medium (2007, July 01) We describe UVES spectroscopic observations towards early-type stars located in the nearby open clusters IC 2391 (D=175 pc) and NGC 6475/M 7 (D=301 pc), with resolution ˜80,000 and S/N ratio per pixel of ... [more ▼] We describe UVES spectroscopic observations towards early-type stars located in the nearby open clusters IC 2391 (D=175 pc) and NGC 6475/M 7 (D=301 pc), with resolution ˜80,000 and S/N ratio per pixel of ˜140 to ˜360. The aim is to investigate the small-scale structure variations within parts of the local ISM and determine how they are dependent on element and ionisation stage observed, thus providing information on cloud parameters such as structure and sizes. The data used are taken from on-line versions of the Paranal Observatory Project (POP: http://www.eso.org/uvespop). A total of 25 early-type stars (A and B-type) are present in our sample towards IC 2391 with 23 towards NGC 6475/M 7, and enable us to probe differences in column densities on scales from ˜0.07--7.3-pc and ˜0.05---4.9-pc (in the respective clusters) for the optical transitions detected (Ti II (3383Å), Ca II (3933Å), Na I (5889, 5895Å) and K I (7698Å)). Towards NGC 6475 the Ca II column density is found to be constant to ˜0.15 dex over scales of ˜0.4--4-pc. A much greater scatter in the measurements for Na I D is observed with differences of up to ˜0.45 dex in sightlines separated by ˜4 pc. In the future work we will perform the same analysis for Ti II and K I towards both clusters. [less ▲] WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE; ; et al in Monthly Notices of the Royal Astronomical Society (2007), 375 We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219-0005465 (GSC 02265-00107 = WASP-1) and USNO-B1.0 0964-0543604 (GSC 00522-01199 = WASP-2). Both stars were identified ... [more ▼] We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219-0005465 (GSC 02265-00107 = WASP-1) and USNO-B1.0 0964-0543604 (GSC 00522-01199 = WASP-2). Both stars were identified as being likely host stars of transiting exoplanets in the 2004 SuperWASP wide-field transit survey. Using the newly commissioned radial-velocity spectrograph SOPHIE at the Observatoire de Haute-Provence, we found that both objects exhibit reflex orbital radial-velocity variations with amplitudes characteristic of planetary-mass companions and in-phase with the photometric orbits. Line-bisector studies rule out faint blended binaries as the cause of either the radial-velocity variations or the transits. We perform preliminary spectral analyses of the host stars, which together with their radial-velocity variations and fits to the transit light curves yield estimates of the planetary masses and radii. WASP-1b and WASP-2b have orbital periods of 2.52 and 2.15 d, respectively. Given mass estimates for their F7V and K1V primaries, we derive planet masses 0.80-0.98 and 0.81-0.95 times that of Jupiter, respectively. WASP-1b appears to have an inflated radius of at least 1.33 R[SUB]Jup[/SUB], whereas WASP-2b has a radius in the range 0.65-1.26 R[SUB]Jup[/SUB]. [less ▲] Detailed reference viewed: 23 (1 ULg)Early-type stars observed in the ESO UVES Paranal Observatory Project - I. Interstellar NaI UV, TiII and CaII K observations*; ; et al in Monthly Notices of the Royal Astronomical Society (2006), 367 We present an analysis of interstellar NaI (λ[SUB]air[/SUB]= 3302.37 and 3302.98 Å), TiII(λ[SUB]air[/SUB]= 3383.76 Å) and CaII K (λ[SUB]air[/SUB]= 3933.66 Å) absorption features for 74 sightlines towards ... [more ▼] We present an analysis of interstellar NaI (λ[SUB]air[/SUB]= 3302.37 and 3302.98 Å), TiII(λ[SUB]air[/SUB]= 3383.76 Å) and CaII K (λ[SUB]air[/SUB]= 3933.66 Å) absorption features for 74 sightlines towards O- and B-type stars in the Galactic disc. The data were obtained from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project, at a spectral resolution of 3.75 km s[SUP]-1[/SUP] and with mean signal-to-noise ratios per pixel of 260, 300 and 430 for the NaI, TiII and CaII observations, respectively. Interstellar features were detected in all but one of the TiII sightlines and all of the CaII sightlines. The dependence of the column density of these three species with distance, height relative to the Galactic plane, HI column density, reddening and depletion relative to the solar abundance has been investigated. We also examine the accuracy of using the NaI column density as an indicator of that for HI. In general, we find similar strong correlations for both Ti and Ca, and weaker correlations for Na. Our results confirm the general belief that Ti and Ca occur in the same regions of the interstellar medium (ISM) and also that the TiII/CaII ratio is constant over all parameters. We hence conclude that the absorption properties of Ti and Ca are essentially constant under the general ISM conditions of the Galactic disc. [less ▲] Detailed reference viewed: 1 (0 ULg) |
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