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Outwards migration for planets in stellar irradiated 3D discs

For the very first time we present 3D simulations of planets embedded in stellar irradiated discs. It is well known that thermal effects could reverse the direction of planetary migration from inwards to outwards, potentially saving planets in the inner, optically thick parts of the protoplanetary disc. When considering stellar irradiation in addition to viscous friction as a source of heating, th

Hunting for Substructure in the Milky Way

Studies of the Milky Way including how it formed and evolved through time are the key to understanding how other galaxies behave. The Milky Way is the most convenient galaxy to study, because the close proximity of stars means astronomers can collect precise spectral and dynamical data from individual stars. By combining the chemical and dynamical aspects, it is possible to pinpoint stars which ha

Common Envelope Evolution

We present simulations done on the onset of common envelope evolution with giant donors by taking into account the mass loss through the outer Lagrange point and the forming of the common envelope. In addition we apply proper stellar models and evolve our simulations using an Runge-Kutta integrator with adaptive step-size. We show that each of these processes are significant in the onset of common

Markov Chain Monte Carlo (MCMC) and Bayesian Inference for Gravitational Waves

The Laser Interferometer Space Antenna (LISA) is a space borne gravitational wave detec- tor set to launch in 2034, with the objective of detecting and studying the Gravitational Waves (GWs) of our universe. So far, ground-based detectors such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) have been successful in detecting GWs, but the limitations of ground based detectors is wh

Carbon Abundance in the Milky Way Galaxy

Carbon is the fourth most abundant element after hydrogen, helium and oxygen. It is a product of stellar nucleosynthesis as well as it being an important bio signature for life; this makes the analysis of carbon very fundamental. The origin of carbon and the relative contributions from massive and low-to-intermediate mass stars in producing it is still under debate. The principal focus of this the

The Tycho-Gala astrometric solution. How to get 2.5 million parallaxes with less than one year of Gala data

Context. The first release of astrometric data from Gala will contain the mean stellar positions and magnitudes from the first year of observations, and proper motions from the combination of Gala data with HIPPARCOS prior information (HTPM). Aims. We study the potential of using the positions from the Tycho-2 Catalogue as additional information for a joint solution with early Gala data. We call t

MOA-2010-BLG-523:" Failed Planet"= RS CVn Star

The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A(max) similar to 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spe

Suppressing low-order eigenmodes with local control for deformable mirrors

To improve the mechanical characteristics of actively controlled continuous faceplate deformable mirrors in adaptive optics, a strategy for reducing crosstalk between adjacent actuators and for suppressing low-order eigenmodes is proposed. The strategy can be seen as extending Saint-Venant's principle beyond the static case, for small local families of actuators. An analytic model is presented, fr

The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo

A small fraction of the halo field is made up of stars that share the light element (Z <= 13) anomalies characteristic of second generation globular cluster (GC) stars. The ejected stars shed light on the formation of the Galactic halo by tracing the dynamical history of the clusters, which are believed to have once been more massive. Some of these ejected stars are expected to show strong Al enha

Magnitude And Color Transformations Between Sirius And 2Mass Photometric Systems

We provide magnitude and color transformations between two near-infrared photometric systems, 2MASS and SIRIUS, the latter currently implemented with the three-Channel SIRIUS camera on 1.4 m Infrared Survey Facility telescope at the South African Astronomical Observatory. The transformation equations are derived using a carefully selected sample of 32 770 stars in the. Large and Small Magellanic C

Systematic trend of water vapour absorption in red giant atmospheres revealed by high resolution TEXES 12 mu m spectra

Context. The structures of the outer atmospheres of red giants are very complex. Recent interpretations of a range of different observations have led to contradictory views of these regions. It is clear, however, that classical model photospheres are inadequate to describe the nature of the outer atmospheres. The notion of large optically thick molecular spheres around the stars (MOLspheres) has b

The Earthshine Telescope Project

The Earthshine telescope project is a collaborative effort between Lund Observatory (LO) in Sweden and the Danish Meteorological Institute (DMI) with the purpose of constructing one or more robotic telescopes to record the albedo of the Earth over a long time. The objective is to measure long-term development of the global cloud cover and reflectivity for climate modeling. A 1% change in the Earth

Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars V. Evidence for a wide age distribution and a complex MDF

Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. Combined with the sample of 26 stars from the previous papers in this series, we now have 58 microlensed bulge dwarfs and subgiants that have been homogeneously analysed. The main characteristics of the sample an