Phytogeographic characterization of Gran Canaria Island (Canary Islands-Spain)

Studies on the flora and fauna of the Canary Islands show that this Archipelago is one of the planet’s diversity hot spots. However, an analysis of the differences in the phytogeographic characteristics of each of the islands that make up this Archipelago is lacking. This article focuses on the phytogeographic characterization of the island of Gran Canaria. This island exhibits geological and climatic characteristics resulting in a rich vascular flora, including endemic species and genera that are significantly different from the other islands of the Archipelago. These differences are verified through statistical analysis of the existing similarity between the floras of the members of the Canary Islands. This study also analyses the subdivision of Gran Canaria Island, indicating that there are three well-differentiated areas on the island itself. Finally, this study argues that these areas, themselves, should be considered biogeographic sectors.

The SuperWASP wide-field exoplanetary transit survey: candidates from fields 23 h <RA <03 h

Photometric transit surveys promise to complement the currently known sample of extra-solar planets (ESPs) by providing additional information on the planets and especially their radii. Here, we present ESP candidates from one such survey called, the Wide Angle Search for Planets (WASP) obtained with the SuperWASP wide-field imaging system. Observations were taken with SuperWASP North located in La Palma during the 2004 April to October observing season. The data cover fields between 23 and 03 h in RA at declinations above +12. This amounts to over ~400000 stars with V magnitudes 8-13.5. For the stars brighter than 12.5, we achieve better than 1 per cent photometric precision. Here, we present 41 sources with low-amplitude variability between ~1 and 10 mmag, from which we select 12 with periods between 1.2 and 4.4 d as the most promising ESP candidates. We discuss the properties of these ESP candidates, the expected fraction of transits recovered for our sample and implications for the frequency and detection of hot-Jupiters.

Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results

We report here the first detection of hectometer-size objects by the method of serendipitous stellar occultation. This method consists of recording the diffraction shadow created when an object crosses the observer's line of sight and occults the disk of a background star. One of our detections is most consistent with an object between Saturn and Uranus. The two other diffraction patterns detected are caused by Kuiper Belt objects beyond 100 AU from the Sun and hence are the farthest known objects in the solar system. These detections show that the Kuiper Belt is much more extended than previously believed and that the outer part of the disk could be composed of smaller objects than the inner part. This gives critical clues to understanding the problem of the formation of the outer planets of the solar system.

The nuclei of comets 7P/Pons-Winnecke, 14P/Wolf and 92P/Sanguin

Jupiter Family comets (JFCs) are short period comets which have recently entered the inner solar system, having previously orbited in the Kuiper Belt since the formation of the planets. We used two nights on the 3.6 m New Technology Telescope (NTT) at the European Southern Observatory, to obtain VRI photometry of three JFCs; 7P/Pons-Winnecke, 14P/Wolf and 92P/Sanguin. These were observed to be stellar in appearance. We find mean effective radii of 2.24 ± 0.02 km for 7P, 3.16 ± 0.01 km for 14P and 2.08 ± 0.01 km for 92P, assuming a geometric albedo of 0.04. From light-curves for each comet we find rotation periods of 7.53 ± 0.10 and 6.22 ± 0.05 h for 14P and 92P respectively. 7P exhibits brightness variations which imply a rotation period of 6.8 = Prot = 9.5 h. Assuming the nuclei to be ellipsoidal the measured brightness variations imply minimum axial ratios a/b of 1.3 ± 0.1 for 7P and 1.7 ± 0.1 for both 14P and 92P. This in turn implies minimum densities of 0.23 ± 0.08 g cm-3 for 7P, 0.32 ± 0.02 g cm-3 for 14P and 0.49 ± 0.06 g cm-3 for 92P. Finally, we measure colour indices of (V-R) = 0.40 ± 0.05 and (R-I) = 0.41 ± 0.06 for 7P/Pons-Winnecke, (V-R) = 0.57 ± 0.07 and (R-I) = 0.51 ± 0.06 for 14P/Wolf, and (V-R) = 0.54 ± 0.04 and (R-I) = 0.54 ± 0.04 for 92P/Sanguin.

Serendipitous Asteroid Lightcurve Survey Using SuperWASP

The SuperWASP project is an ultra-wide angle search for extra solar planetary transits. However, it can also serendipitously detect solar system objects, such as asteroids and comets. Each SuperWASP instrument consists of up to eight cameras, combined with high-quality peltier-cooled CCDs, which photometrically survey large numbers of stars in the magnitude range 7 15. Each camera covers a 7.8 × 7.8 degree field of view. Located on La Palma, the SuperWASP-I instrument has been observing the Northern Hemisphere with five cameras since its inauguration in April 2004. The ultra-wide angle field of view gives SuperWASP the possibility of discovering new fast moving (near to Earth) asteroids that could have been missed by other instruments. However, it provides an excellent opportunity to produce a magnitude-limited lightcurve survey of known main belt asteroids. As slow moving asteroids stay within a single SuperWASP field for several weeks, and may be seen in many fields, a survey of all objects brighter than magnitude 15 is possible. This will provide a significant increase in the total number of lightcurves available for statistical studies without the inherent bias against longer periods present in the current data sets. We present the methodology used in the automated collection of asteroid data from SuperWASP and some of the first examples of lightcurves from numbered asteroids.

Probing warm dense lithium by inelastic X-ray scattering

One of the grand challenges of contemporary physics is understanding strongly interacting quantum systems comprising such diverse examples as ultracold atoms in traps, electrons in high-temperature superconductors and nuclear matter. Warm dense matter, defined by temperatures of a few electron volts and densities comparable with solids, is a complex state of such interacting matter. Moreover, the study of warm dense matter states has practical applications for controlled thermonuclear fusion, where it is encountered during the implosion phase, and it also represents laboratory analogues of astrophysical environments found in the core of planets and the crusts of old stars, Here we demonstrate how warm dense matter states can be diagnosed and structural properties can be obtained by inelastic X-ray scattering measurements on a compressed lithium sample. Combining experiments and ab initio simulations enables us to determine its microscopic state and to evaluate more approximate theoretical models for the ionic structure.

The evolution of solar systems

The recent detection of extra-solar planets and the increasing ability of modern instruments to image discs around young stars has brought a renewed interest in the formation of solar systems. In this article, I shall briefly review what we know about extra-solar planets and the physical structure of protostellar discs. One of the most powerful means of studying these disc systems is to observe the rotational line emission from molecules which can give information on physics and dynamics. At present, the observations are relatively crude but future instruments should be able to resolve molecular structures in the disc around nearby stars. As a prelude to these observations, I discuss some conceptually simple, although numerically challenging, models of the physical and chemical processes involved in determining the molecular distributions.

A Transit Timing Analysis of Mine RISE Light Curves of the Exoplanet System TrES-3

We present nine newly observed transits of TrES-3, taken as part of a transit timing program using the RISE instrument on the Liverpool Telescope. A Markov-Chain Monte Carlo analysis was used to determine the planet star radius ratio and inclination of the system, which were found to be R-p/R-star = 0.1664(-0.0018)(+0.0011) and i = 81.73(-0.04)(+0.13), respectively, consistent with previous results. The central transit times and uncertainties were also calculated, using a residual-permutation algorithm as an independent check on the errors. A re-analysis of eight previously published TrES-3 light curves was conducted to determine the transit times and uncertainties using consistent techniques. Whilst the transit times were not found to be in agreement with a linear ephemeris, giving chi(2) = 35.07 for 15 degrees of freedom, we interpret this to be the result of systematics in the light curves rather than a real transit timing variation. This is because the light curves that show the largest deviation from a constant period either have relatively little out-of-transit coverage or have clear systematics. A new ephemeris was calculated using the transit times and was found to be T-c(0) = 2454632.62610 +/- 0.00006 HJD and P = 1.3061864 +/- 0.0000005 days. The transit times were then used to place upper mass limits as a function of the period ratio of a potential perturbing planet, showing that our data are sufficiently sensitive to have probed sub-Earth mass planets in both interior and exterior 2:1 resonances, assuming that the additional planet is in an initially circular orbit.

Wasp-7: A Bright Transiting-Exoplanet System in the Southern Hemisphere

We report that a Jupiter-mass planet, WASP-7b, transits the V = 9.5 star HD 197286 every 4.95 d. This is the brightest discovery from the WASP-South transit survey so far and is currently the brightest transiting-exoplanet system in the southern hemisphere. WASP-7b is among the densest of the known Jupiter-mass planets, suggesting that it has a massive core. The planet mass is 0.96+0.12 -0.18 M Jup, the radius is 0.915+0.046 -0.040 R Jup, and the density is 1.26+0.25 -0.21 ?Jup (1.67+0.33 -0.28 g cm-3).

The masses and radii of HD 186753B and TYC7096-222-1B: the discovery of two M-dwarfs that eclipse A-type stars

We present observations of two new single-lined eclipsing binaries, both consisting of an Am star and an M-dwarf, discovered by the Wide Angle Search for Planets transit photometry survey. Using WASP photometry and spectroscopic measurements we find that HD 186753B has an orbital period of P=1.9194 days, a mass of M=0.24±0.02~M? and radius of R=0.31+0.06-0.06~R?; and that TCY7096-222-1B has an orbital period of P=8.9582 days, a mass of between 0.29 and 0.54 M? depending on eccentricity and radius of R=0.263+0.02-0.07~R?. We find that the Am stars have relatively low rotational velocities that closely match the orbital velocities of the M-dwarfs, suggesting that they have been “spun-down” by the M-dwarfs.

Humanitarian Travels: Ethical Communication in Lonely Planet Guidebooks

Aside from the more mundane purpose of telling us where to eat, sleep and sightsee in foreign lands, guidebooks communicate an ethical vision that sees travel as the key to reducing cultural differences and inequalities. This article argues that Lonely Planet guidebooks in particular encourage a form of ‘responsible independent travel’ that both reflects and produces a powerful discourse of humanitarianism. By examining the controversy over Lonely Planet’s publication of guidebooks to Burma, this article uncovers the problematic colonial logic embedded in that ethical vision.

WASP-19b: The Shortest Period Transiting Exoplanet Yet Discovered

We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass M pl = 1.15 ± 0.08 MJ , radius R pl = 1.31 ± 0.06 RJ , and orbital period P = 0.7888399 ± 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 ± 0.1 dex) G-dwarf with T eff = 5500 ± 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of P rot = 10.5 ± 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (~ 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q' s , if a more precise age is determined.

A transit timing analysis of seven RISE light curves of the exoplanet system HAT-P-3

We present seven light curves of the exoplanet system HAT-P-3, taken as part of a transit timing programme using the rapid imager to search for exoplanets instrument on the Liverpool Telescope. The light curves are analysed using a Markov chain Monte Carlo algorithm to update the parameters of the system. The inclination is found to be i = 86.75+0.22-0.21°, the planet-star radius ratio to be Rp/R* = 0.1098+0.0010-0.0012 and the stellar radius to be R* = 0.834+0.018-0.026Rsolar, consistent with previous results but with a significant improvement in the precision. Central transit times and uncertainties for each light curve are also determined, and a residual permutation algorithm is used as an independent check on the errors. The transit times are found to be consistent with a linear ephemeris, and a new ephemeris is calculated as Tc(0) = 2454856.70118 +/- 0.00018 HJD and P = 2.899738 +/- 0.000007 d. Model timing residuals are fitted to the measured timing residuals to place upper mass limits for a hypothetical perturbing planet as a function of the period ratio. These show that we have probed for planets with masses as low as 0.33 and 1.81 M? in the interior and exterior 2:1 resonances, respectively, assuming the planets are initially in circular orbits.

Ground-based detection of thermal emission from the exoplanet WASP-19b

We present an occultation of the newly discovered hot Jupiter system WASP-19, observed with the High Acuity Wide-field K-band Imager instrument on the VLT, in order to measure thermal emission from the planet's dayside at ~2µm. The light curve was analysed using a Markov Chain Monte Carlo method to find the eclipse depth and the central transit time. The transit depth was found to be 0.366 +/- 0.072 per cent, corresponding to a brightness temperature of 2540 +/- 180 K. This is significantly higher than the calculated (zero-albedo) equilibrium temperature and indicates that the planet shows poor redistribution of heat to the night side, consistent with models of highly irradiated planets. Further observations are needed to confirm the existence of a temperature inversion and possibly molecular emission lines. The central eclipse time was found to be consistent with a circular orbit.

The spin-orbit alignment of the transiting exoplanet WASP-3b from Rossiter-McLaughlin observations

We present an observation of the Rossiter-McLaughlin effect for the planetary system WASP-3. Radial velocity measurements were made during transit using the SOPHIE spectrograph at the 1.93-m telescope at Haute-Provence Observatory. The shape of the effect shows that the sky-projected angle between the stellar rotation axis and planetary orbital axis (?) is small and consistent with zero within . WASP-3b joins the ~two-thirds of planets with measured spin-orbit angles that are well aligned and are thought to have undergone a dynamically gentle migration process such as planet-disc interactions. We find a systematic effect which leads to an anomalously high determination of the projected stellar rotational velocity (vsini = 19.6+2.2-2.1kms-1) compared to the value found from spectroscopic line broadening (vsini = 13.4 +/- 1.5kms-1). This is thought to be caused by a discrepancy in the assumptions made in the extraction and modelling of the data. Using a model developed by Hirano et al. designed to address this issue, we find vsini to be consistent with the value obtained from spectroscopic broadening measurements (vsini = 15.7+1.4-1.3kms-1).