By studying the radial distribution of the properties of stellar populations in 15 nearby S0 galaxies, I have found that the outer stellar disks are mostly old, with SSP-equivalent ages of 8–15 Gyr, often being older than the bulges. This fact throws doubt on the currently accepted paradigm that S0 galaxies were formed at z=0.4 through the quenching of star formation in spiral galaxies.

In this contribution we present 4 complete planetary transits observed with the 40-cm telescope “Horacio Ghielmetti” located in San Juan(Argentina). These objects correspond to a continuous photometric monitoring program of Southern planet host-stars that we are carrying out since mid-2011. The goal of this project is to detect additional planetary mass objects around stars with known transiting-planets through Transit Timing Variations (TTVs). For all 4 transits the depth and duration are in good agreement with the values published in the discovery papers.

111 posters were displayed at IAU S285. They were divided arbitrarily into two groups, the changeover taking place between Tuesday and Wednesday.

We argue that detonations of sub-Chandrasekhar mass white dwarfs can lead to bright explosions with light curves and spectra similar to those of observed Type Ia supernovae. Given that binary systems containing accreting sub-Chandrasekhar mass white dwarfs should be common, this suggests that a non-negligible fraction of the observed Type Ia supernova rate may arise from sub-Chandrasekhar mass explosions, if they can be ignited. We discuss aspects of how such explosions might be realized in nature and both merits and challenges associated with invoking sub-Chandrasekhar mass explosion models to account for observed Type Ia supernovae.

We present the results of modelling the polarization resulting from the planetary transits and stellar spots in the system Corot-2 using the Monte Carlo method. The planetary transit was estimated to produce a polarization maximum at the limb of ~5 × 10−6, adopting solar center-to-limb polarization. Assuming different parameters of the spots, we evaluated the flux and polarization changes due to the stellar activity.

The WG was created in 2008 to progress UNESCO's Astronomy and World Heritage Initiative (AWHI) jointly with the World Heritage Centre, following the signing of a formal Memorandum of Understanding between the IAU and UNESCO.

Using three-dimensional (special relativistic) magnetohydrodynamics simulations, the amplification of magnetic field behind strong shock wave is studied. In supernova remnants and gamma-ray bursts, strong shock waves propagate through an inhomogeneous density field. When the shock wave hit a density bump or density dent, the Richtmyer-Meshkov instability is induced that cause a deformation of the shock front. The deformed shock leaves vorticity behind the shock wave that amplifies the magnetic field due to the stretching of field lines.

In this talk, we review the basic assumptions and physics covered by classical 1D LTE model atmospheres. We will focus on ATLAS and MARCS models of F-G-K stars and describe what resources are available through the web, both in terms of codes and model-atmosphere grids. We describe the advances made in hydrodynamical simulations of convective stellar atmospheres with the CO5BOLD code and what grids and resources are available, with a prospect of what will be available in the near future.

We present results from systematic Herschel/HIFI observations of molecular lines in the FIR/sub-mm from young planetary nebulae. The high spectral resolution provided by the hetorodyne spectrometer HIFI allows properly studying the line profiles, whose structure corresponds to the various kinematics of the most massive nebular components, including fast bipolar outflows and slow shells. In particular, we have studied the excitation properties of the high-velocity (dense) flows. In some cases we find typical temperatures of the fast gas over 100-200 K, though in others it remains cool, ≲30K. We argue that the thermodynamics of the molecule-rich bipolar outflows is driven by fast radiative cooling, after the passage of the shock that accelerated it.

The Large Aperture GRBs Observatory is a continental-wide observatory devised to detect high energy (around 100 GeV) component of Gamma Ray Bursts (GRBs), by using the single particle technique in arrays of Water Cherenkov Detectors (WCDs) at high mountain sites of Argentina, Bolivia, Colombia, Guatemala, Mexico, Venezuela and Peru. Details of the instalation and operation of the detectors in Marcapomacocha in Peru at 4550 m.a.s.l. are given. The detector calibration method will also be shown.

The activities of the Commission have continued to focus on controlling unwanted light and radio emissions at observatory sites, monitoring of conditions at observatory sites, and education and outreach. Commission members have been active in securing new legislation in several locations to further the protection of observatory sites as well as in the international regulation of the use of the radio spectrum and the protection of radio astronomical observations.

We perform an all-sky search for classical (type I) Cepheids that are members of Galactic Open Clusters. Our approach is multi-dimensional, using all available spatial and kinematic parameters. The quantification of errors is crucial for this analysis, so care is taken to find adequate and realistic representations of parameter uncertainties. The data employed in the calculation are taken from published catalogues and the literature, supplemented by specific radial-velocity observations. Our work in progress is outlined here, and issues related to the inhomogeneity of cluster radii in the literature are discussed in some detail.

Many elliptical galaxies possess an appreciable amount of X-ray-emitting hot plasma, providing a harsh interstellar environment for the survival of dust grains and polycyclic aromatic hydrocarbons (PAHs). Despite such a hostile environment, it has been found that a significant fraction of X-ray elliptical galaxies contain a considerable amount of dust, which cannot be explained solely from replenishment by old stars. Some of them even show the presence of PAHs. We present the results of AKARI and Spitzer observations of dust and PAHs in X-ray elliptical galaxies. We investigate their possible origins and discuss the implications of their presence for the evolution of elliptical galaxies.

We present observational and theoretical studies constraining Type Ia supernova progenitors.

First, we use a new observational technique to show that “prompt” SNe Ia that trace star-formation on cosmic timescales exhibit a significant delay time of 200-500 million years. This implies that either the majority of SNe Ia companion stars have main-sequence masses less than three solar masses, or that most SNe Ia arise from double-white dwarf binaries.

Second we present a comprehensive study of white dwarf collisions as an avenue for creating SNe Ia. Using a smooth particle hydrodynamics code with a 13-isotope nuclear network, we show that several combinations of white dwarf masses and impact parameters produce enough 56Ni to result in luminosities ranging from those of sub-luminous to super-luminous SNe Ia, depending on the parameters of the collision.

Finally, we conduct a simulation survey of double-degenerate white dwarf mergers with varying mass combinations. Unlike previous works, we do not add detonations by hand to our simulations, and we do not find any thermonuclear explosions during the mergers. Instead, all but one of our simulations forms a cold, degenerate core surrounded by a hot disk, while our least massive pair of stars forms only a hot disk. We characterize the remnants by core mass, rotational velocity, and half-mass radius, and discuss how we will evolve them further with simulations that incorporate dissipative processes. Such simulations may indeed lead to double-degenerate Type Ia explosions that occur many orbits after the mergers themselves.

We investigate a proto-neutron star kick velocity estimated from kinetic momentum of a flow around the proto-neutron star after the standing accretion shock instability grows. In this study, ten different types of random perturbations are imposed on the initial flow for each neutrino luminosity. We found that the kick velocities of proto-neutron star are widely distributed from 40 km s−1 to 180 km s−1 when the shock wave reaches 2000 km away from the center of the star. The average value of kick velocity is 115 km s−1, whose value is smaller than the observational ones. The kick velocities do not depend on the neutrino luminosity.

Commission 55 was approved at the IAU General Assembly in Prague following the great success of the Communicating Astronomy Working Group, which had been set up in 2003. It resides within Division XII and the mission statement of the Working Group has been incorporated into the Commission:

• • To encourage and enable a much larger fraction of the astronomical community to take an active role in explaining what we do (and why) to our fellow citizens.

• • To act as an international, impartial coordinating entity that furthers the recognition of outreach and public communication on all levels in astronomy.

• • To encourage international collaborations on outreach and public communication.

• • To endorse standards, best practices and requirements for public communication.

Early-type galaxies (ETGs) are thought to be devoid of dust and star-formation, having formed most of their stars at early epochs. We present the detection of the dustiest ETGs in a large area blind submillimetre survey with Herschel (H-ATLAS, Eales et al. 2010), where the lack of pre-selection in other bands makes it the first unbiased survey for cold dust in ETGs. We compare to a control sample of optically selected ETGs to investigate how the two populations are different. We also highlight the properties of an interesting population of passive spirals detected by Herschel.

After very dense and slow winds erode the outer layer of an asymptotic giant branch (AGB) star down to a thin H-rich layer (≃10−3 M⊙) the star becomes a post-AGB star and evolves at constant luminosity towards hotter temperatures. It may then becomes a planetary nebula nucleus (PNN) at the centre of a planetary nebula (PN). During these phases, the thin H-rich surface layer of the star is eroded by winds. Stardust oxide and silicate grains are recovered from meteorites. The origin of the “Group II grains” that show enrichments in 17O and depletions in 18O is currently explained by invoking the occurrence of some kind of extra-mixing process in AGB stars. We suggest instead that these grains originated from the winds of post-AGB stars and PNN. These winds show the signature of H-burning. We will do this by comparing our predictions from stellar models to the compositions observed in Group II stardust oxide and silicate grains. We find that the composition of the thin H-rich layer lost in the post-AGB and PNN winds is close to that of Group II grains, however the match with the Al ratios needs to be improved. Considering the uncertainities in the 25Mg and 26Al proton capture rates may be helped in this respect.

One of the greatest factors that significantly affect the quality of astronomical images is the atmospheric turbulence causing what we call “seeing”. We present results of the reduction and photometry of astronomical images obtained at the Sasahuine mountain astronomical site (4511 m.a.s.l.), located in the Southern Peruvian Andes, in the department of Moquegua, near the town of Cambrune. These data show preliminary seeing measurements for this site. The present work is part of a bigger investigation program called JANAX which seeks to evaluate potential astronomical observation sites in Peruvian territory through a series of observation missions. The program's aim is to gather data to validate the site for the future construction of a National Astronomical Observatory. The observations were made using an SBIG ST-7MX CCD camera and a BVR standard filter set, attached to a MEADE LX200 356mm telescope.

We investigate the effects of neutrino-nucleus interactions on the production of Fluorine during normal supernovae and hypernovae, and discuss stellar mass, metallicity and explosion energy dependence of [F/Fe,Ne,O]. We find the clear trend of [F/Fe,O,Ne] with stellar mass and explosion energy, while no clear trend with metallicity. This trend of [F/O] can be used to constrain the contributed stellar mass by comparing with the observational abundance.