We report the results of maximum entropy eclipse-mapping analysis of an ensemble of light curves of the dwarf nova V4140 Sagitarii (V4140 Sgr) with the objective of studying the spatial distribution of its steady-light and flickering sources in quiescence, and the changing disk structure during an outburst.

Recent studies have shown that for suitable initial conditions both super- and sub-Chandrasekhar mass carbon-oxygen white dwarf mergers produce explosions similar to observed SNe Ia. The question remains, however, how much fine tuning is necessary to produce these conditions. We performed a large set of SPH merger simulations, sweeping the possible parameter space. We find trends for merger remnant properties, and discuss how our results affect the viability of our recently proposed sub-Chandrasekhar merger channel for SNe Ia.

Most popular computer codes for calculating model stellar and planetary atmospheres are briefly reviewed. A particular emphasis is devoted to our universal computer program Tlusty (model stellar atmospheres and accretion disks), CoolTlusty (a variant of Tlusty for computing model atmospheres of substellar-mass objects such as giant planets and brown dwarfs), and Synspec (an associated spectrum synthesis code). We show the highlights of actual applications of these codes which include extensive grids of fully line-blanketed non-LTE model atmospheres of O and B stars, and grids of model atmospheres of extrasolar giant planets and L and T dwarfs.

Fullerenes, the carbon molecules with 60 and 70 atoms, were recently detected in a series of planetary nebulae, in protoplanetary nebulae and in other astrophysical objects. The detection and the quantitative determination of these molecules was made possible by the measurement of their reference infrared spectra and the relative molar extinction coefficients and integrated molar absorptivity on laboratory scale. It is expected that also fulleranes the hydrogenated derivatives of C60 and C70 may be present in the same objects where fullerenes were detected. This prompted us to synthesize the hydrogenated fullerenes, to record their infrared spectra and the measure the molar extinction coefficients and integrated molar absorptivity on laboratory scale to have a reference in the search of these fullerene derivatives in space

Some 10 years ago the IAU Executive Committee created a Working Group on Future Large Scale Facilities, but its activities have fallen somewhat into abeyance in the last few years. It has been decided to revive the group, and Roger Davies (Oxford) has agreed to chair it.

Among the possible progenitor scenarios considered for Type Ia supernovae, those that involve a carbon–oxygen white dwarf (CO WD) accreting stably towards the Chandrasekhar mass should undergo a phase of hydrostatic carbon burning under high densities and strong convection: the simmering or carbon–flash phase, which can extend for a few hundred years before explosion. During this phase the progenitor CO WD can burn a small fraction of its carbon hydrostatically, releasing energy and ashes that make the star convective and able to capture electrons from the degenerate plasma. In this work we present simplified pre–supernova evolution models of CO WDs growing towards the Chandrasekhar mass accreting matter stably and evolving through the simmering phase towards ignition in order to explore the effects of different initial masses and cooling times in the final chemical composition of the WD before explosion. Preliminary results show that, as expected, denser systems at the start of the simmering phase undergo stronger neutronization. The amount of neutronization is less than what is found in the one–zone models of Chamulak et al. (2008), about a third, and can vary by about a factor of two depending on the exact path to explosion.

We describe very high-time-resolution photometers capable of tagging the arrival time of each photon with a resolution and accuracy of few hundred picoseconds, for hours of continuous acquisition, and with a dynamic range of more than 6 orders of magnitude. The final goal is the conceptual definition of a “quantum” photometer for the E-ELT, capable of detecting and measuring second-order correlation effects in photon streams from celestial sources. Two prototype units have been built and operated, one for the Asiago 1.8-m telescope (AquEYE) and one for the 3.5-m NTT (IquEYE).Here we will present results obtained by IquEYE on the Crab Nebula pulsar in simultaneous radio observations with Jodrell Bank in December 2009.

cmfgen is an atmosphere code developed to model the spectra of a variety of objects – O stars, Wolf-Rayet stars, luminous blue variables, A and B stars, central stars of planetary nebula, and supernovae. The principal computational aim of cmfgen is to determine the temperature and ionization structure of the atmosphere, and the atomic level populations. Toward this end, we have developed several different radiative transfer modules that (a) solve the transfer equation for spherical geometry in the comoving frame, (b) solve the static transfer equation in the plane parallel approximation without, or with, a vertical velocity field, (c) solve the static transfer code for a spherical atmosphere allowing for all relativistic terms, (d) solve the time-dependent spherical transfer equation to first order in v/c for a homologous expansion, and (e) solve the time-dependent spherical transfer equation allowing for all relativistic terms. To achieve consistency between the radiation field, temperature structure, and level populations we use a linearization technique. Line blanketing is accurately treated while complex photoionization cross-sections, containing numerous resonances, can also be handled. Spectra, for comparison with observation, are computed using cmf_flux. Several other auxiliary programs have also been developed – these include diagnostic tools as well as programs that allow the effect on spectra of rotation and departures from spherical geometry to be investigated. In this presentation we will briefly describe cmfgen and auxiliary codes.

Hierarchical galaxy formation models predict the development of elliptical galaxies through a combination of the mergers and interactions of smaller galaxies. We are carrying out a study of Early-Type Galaxies (ETGs) using GAMA multi-wavelength and Herschel-ATLAS sub-mm data to understand their intrinsic dust properties. The dust in some ETGs may be a relic of past interactions and mergers of galaxies, or may be produced within the galaxies themselves. With this large dataset we will probe the properties of the dust and its relation to host galaxy properties. This paper presents our criteria for selecting ETGs and explores the usefulness of proxies for their morphology, including optical colour, Sérsic index and Concentration index. We find that a combination of criteria including r band Concentration index, ellipticity and apparent sizes is needed to select a robust sample. Optical and sub-mm parameter diagnostics are examined for the selected ETG sample, and the sub-mm data are fitted with modified Planck functions giving initial estimates for the cold dust temperatures and masses.

We describe the database and the method used to analyze the sunspot data recorded at the Solar Observatory of the University of Ica in Peru. The parameters that are measured include the relative sunspot number (R), the sunspot area, their positions on the disk, and an estimate of the constant (k) included in R. Sunspots in the database are classified following the Zurich Classification System. From these observations, the active region area, the sunspot rotation speed, and other active regions properties can be estimated.

We investigate the lowest mass stars that produce Type-II supernovae, motivated by recent results showing that a large fraction of type-II supernova progenitors for which there are direct detections display unexpectedly low luminosity (for a review see e.g. Smartt 2009). There are three potential evolutionary channels leading to this fate. Alongside the standard ‘massive star’ Fe-core collapse scenario we investigate the likelihood of electron capture supernovae (EC-SNe) from super-AGB (S-AGB) stars in their thermal pulse phase, from failed massive stars for which neon burning and other advanced burning stages fail to prevent the star from contracting to the critical densities required to initiate rapid electron-capture reactions and thus the star's collapse. We find it indeed possible that both of these relatively exotic evolutionary channels may be realised but it is currently unclear for what proportion of stars. Ultimately, the supernova light curves, explosion energies, remnant properties (see e.g. Knigge et al. 2011) and ejecta composition are the quantities desired to establish the role that these stars at the lower edge of the massive star mass range play.

In view of their nature, planetary nebulae have very short lifetimes, and the chemical abundances derived so far have a natural bias favoring younger objects. In this work, we report physical parameters and abundances for a sample of old PNe located in the galactic bulge, based on low dispersion spectroscopy secured at the SOAR telescope using the Goodman Spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebula luminosity function (PNLF). The results show that the abundances of our sample are lower than those from our previous work. Additionally, the average abundances of the galactic bulge do not follow the observed trend of the radial abundance gradient in the disk. These results are in agreement with a chemical evolution model for the Galaxy recently developed by our group.

The San Luis Gonzaga National University of Ica has built a solar station, in collaboration with the Geophysical Institute of Peru, the National Astronomical Observatory of Japan and the Hida Observatory. The Solar Station has the following equipment: a digital Spectrograph Solar Refractor Telescope Takahashi 15 cm aperture, 60 cm reflector telescope aperture, a magnetometer-MAGDAS/CPNM and a Burst Monitor Telescope Solar-FMT (Project CHAIN). These teams support the development of astronomical science and Ica in Peru, likewise contributing to science worldwide. The development of basic science will be guaranteed when university students, professors and researchers work together. The Solar Station will be useful for studying the different levels of university education and also for the general public. The Solar Station will be a good way to spread science in the region through public disclosure.

The Working Group was created at the 25th IAU General Assembly in Sydney, Australia, in July 2003 by the IAU Executive Council as a Working Group of IAU Executive. The aims of the Working Group are to evaluate the status of women in astronomy through the collection of statistics over all countries where astronomy research is carried out; and to establish strategies and actions that can help women to attain true equality as research astronomers, which will add enormous value to all of astronomy.

In this review, I summarize the observational attempts made so far to unveil the nature of the progenitor system(s) of Type Ia supernovae. In particular, I focus on the most recent developments that followed the claimed detection of circumstellar material around a few events, and on the link this possibly establishes with recurrent novae. In this framework, I then discuss the case of RS Oph, what we know of its circumstellar environment, and what this is telling us about its supposed connection to Type Ia supernovae explosions.

We have obtained optical integral field spectroscopy of the explosion sites of more than 25 nearby type-IIP/IIL/Ib/Ic supernovae using UH88/SNIFS, and additionally Gemini/GMOS IFU. This technique enables us to obtain both spatial and spectral information of the immediate environment of the supernovae. Using strong line method we measured the metallicity of the star cluster present at the explosion site, presumably the coeval parent stellar population of the supernova progenitor, and comparison with simple stellar population models gives age estimate of the cluster. With this method we were able to put constraints on the metallicity and age of the progenitor star. The age, i.e. lifetime, of the progenitor corresponds to the initial mass of the star. By far this is the most direct measurement of supernova progenitor metallicity and, if the cluster-progenitor association is confirmed, provides reliable determination of the initial mass of supernova progenitor stars.

The Kepler Guest Observer Office is dedicated to the service of the broad science community, with a charter to promote the exploitation of Kepler data and broaden the scientific impact of the Kepler mission. There are four routes by which to gain access to Kepler data: the Guest Observer programme annual call for proposals, the quarterly call for Director's Discretionary Targets, the Kepler Asteroseismic Science Consortium, and by accessing the Kepler public data archive. The Guest Observer Office supports all users of Kepler data no matter which route they took to access data, and to that end have developed software tools which can be used by the community in their data analyses.

The spectral transition from Very Low Mass stars (VLMs) to brown dwarfs (BDs) and planetary mass objects (Planemos) requires model atmospheres that can treat line, molecule, and dust-cloud formation with completeness and accuracy. One of the essential problems is the determination of the surface velocity field throughout the main sequence down to the BD and planemo mass regimes. We present local 2D and 3D radiation hydrodynamic simulations using the CO5BOLD code with binned Phoenix gas opacities, forsterite dust formation (and opacities) and rotation. The resulting velocity field vs depth and Teff has been used in the general purpose model atmosphere code Phoenix, adapted in static 1D spherical symmetry for these cool atmospheres. The result is a better understanding of the spectral transition from the stellar to substellar regimes. However, problems remain in reproducing the colors of the dustiest brown dwarfs. The global properties of rotation can change the averaged spectral properties of these objects. Our project for the period 2011-2015 is therefore to develop scaled down global 3D simulations of convection, cloud formation and rotation thanks to funding by the Agence Nationale de la Recherche in France.

We investigate the possibility of using Luminous Red Galaxies (LRGs) as “Cosmic chronometers” to measure the expansion rate of the universe to 3% over a redshift range 0.1 < z < 1.0. In this method, H(z) is directly measured by using the ages of passively evolving galaxies to determine dz/dt. We first present results from our study of LRGs in simulations Crawford et al. where we explore the impact of extended star formation histories on the measurements of the Hubble parameter. We then extract a carefully selected sample of LRGs taken from Sloan Digital Sky Survey (SDSS) Data Released Seven (DR7), stack spectra in redshift bins to increase the signal-to-noise, and use the Lick index modelling presented in Thomas et al. to age-date the sample. We discuss the implications for expansion rate measurements and outline a proposal to observe LRGs with the Southern African Large Telescope (SALT).

Limb-darkening is a fundamental constraint for modeling eclipsing binary and planetary transit light curves. As observations, for example from Kepler, CoRot, and Most, become more precise then a greater understanding of limb-darkening is necessary. However, limb-darkening is typically modeled as simple parameterizations fit to plane-parallel model stellar atmospheres that ignores stellar atmospheric extension. In this work, I compute linear, quadratic and four-parameter limb-darkening laws from grids of plane-parallel and spherically-symmetric model stellar atmospheres in a temperature and gravity range representing stars evolving on the Red Giant branch. The limb-darkening relations for each geometry are compared and are found to fit plane-parallel models much better than the spherically-symmetric models. Assuming that limb-darkening from spherically-symmetry model atmospheres are more physically representative of actual stellar limb-darkening than plane-parallel models, then these limb-darkening laws will not fit the limb of a stellar disk leading to errors in a light curve fit. This error will increase with a star's atmospheric extension.