We use the full SED of a well observed dwarf galaxy, I Zw 18, to evaluate what inferences can be made about very high-redshift galaxies from their UV SED's alone.

The long-period binary system AU Mon was photometrically observed on-board the CoRoT satellite in a continuous run of almost 60 days long which has covered almost 5 complete cycles. Unprecedented sub milimag precision of CoRoT photometry reveals all complexity of its light variations in this, still active mass-transfer binary system. We present images of an accretion disk reconstructed by eclipse mapping, and an optimization of intensity distribution along disk surface. Time resolution and accurate CoRoT photometric measurements allow precise location of spatial distribution of ‘hot’ spots on the disk, and tracing temporal changes in their activity. Clumpy disk structure is similar to those we detected early for another W Serpentis binary W Cru (Pavlovski, Burki & Mimica, 2006, A&A, 454, 855).

The properties of the Supernovae discovered in coincidence with long-duration Gamma-ray Bursts and X-Ray Flashes are reviewed, and compared to those of SNe for which GRBs are not observed. The SNe associated with GRBs are of Type Ic, they are brighter than the norm, and show very broad absorption lines in their spectra, indicative of high expansion velocities and hence of large explosion kinetic energies. This points to a massive star origin, and to the birth of a black hole at the time of core collapse. There is strong evidence for gross asymmetries in the SN ejecta. The observational evidence seems to suggest that GRB/SNe are more massive and energetic than XRF/SNe, and come from more massive stars. While for GRB/SNe the collapsar model is favoured, XRF/SNe may host magnetars.

Mass loss on the AGB removes most of the envelope and leaves a compact remnant to become a white dwarf and perhaps first the central star of a planetary nebula. The envelope mass provides an upper limit on the material available to form the PN, and the terminal mass loss rate plus the small remnant mass left on the core determines how much of that would still be available to form the PN after the star has evolved far enough to the blue. Given a mass loss formula based on observations or models, we can find the deathline where −dMstar/dt = (M/L) dL/dt and can find the contours of constant mass loss rate on a plot of M vs. L. From such plots we can derive the mass available for a PN and the lowest mass single star that can produce a PN of a given mass. However, some details important for PN formation remain uncertain, including the maximum mass loss rate achieved and the envelope mass left when AGB mass loss ceases.

The slow decline of solar Cycle 23 combined with the slow rise of Cycle 24 resulted in a very long period of low magnetic activity during the years 2007–2009 with sunspot number reaching the lowest level since 1913. This long solar minimum was characterized by weak polar magnetic fields, smaller polar coronal holes, and a relatively complex coronal morphology with multiple streamers extending to mid latitudes. At the same time, low latitude coronal holes remained present on the Sun until the end of 2008 modulating the solar wind at the Earth in co-rotating, fast solar wind streams. This magnetic configuration was remarkably different from the one observed during the previous two solar minima when coronal streamers were confined near the equator and the fast solar wind was mainly originating from the large coronal holes around the Sun's poles. This paper presents the evolution of the polar magnetic fields and coronal holes during the past minimum, compare it with the previous minima, and discuss the implications for the solar wind near the Earth. It also considers the minimum of Cycle 23 in an historical perspective and, in particular, compares it to the long minima at the turn of the 19th century.

The Tübingen NLTE Model-Atmosphere Package (TMAP) calculates fully metal-line blanketed white dwarf model atmospheres and spectral energy distributions (SEDs) at a high level of sophistication. Such SEDs are easily accessible via the German Astrophysical Virtual Observatory (GAVO) service TheoSSA. We discuss applications of TMAP models to (pre) white dwarfs during the hottest stages of their stellar evolution, e.g. in the parameter range of novae and supersoft sources.

Commission 10 of the International Astronomical Union has more than 650 members who study a wide range of activity phenomena produced by our nearest star, the Sun. Solar activity is intrinsically related to solar magnetic fields and encompasses events from the smallest energy releases (nano- or even picoflares) to the largest eruptions in the Solar System, coronal mass ejections (CMEs), which propagate into the Heliosphere reaching the Earth and beyond. Solar activity is manifested in the appearance of sunspot groups or active regions, which are the principal sources of activity phenomena from the emergence of their magnetic flux through their dispersion and decay. The period 2008–2009 saw an unanticipated extended solar cycle minimum and unprecedentedly weak polar-cap and heliospheric field. Associated with that was the 2009 historical maximum in galactic cosmic rays flux since measurements begun in the middle of the 20th Century. Since then Cycle 24 has re-started solar activity producing some spectacular eruptions observed with a fleet of spacecraft and ground-based facilities. In the last triennium major advances in our knowledge and understanding of solar activity were due to continuing success of space missions as SOHO, Hinode, RHESSI and the twin STEREO spacecraft, further enriched by the breathtaking images of the solar atmosphere produced by the Solar Dynamic Observatory (SDO) launched on 11 February 2010 in the framework of NASA's Living with a Star program. In August 2012, at the time of the IAU General Assembly in Beijing when the mandate of this Commission ends, we will be in the unique position to have for the first time a full 3-D view of the Sun and solar activity phenomena provided by the twin STEREO missions about 120 degrees behind and ahead of Earth and other spacecraft around the Earth and ground-based observatories. These new observational insights are continuously posing new questions, inspiring and advancing theoretical analysis and modelling, improving our understanding of the physics underlying magnetic activity phenomena. Commission 10 reports on a vigorously evolving field of research produced by a large community. The number of refereed publications containing ‘Sun’, ‘heliosphere’, or a synonym in their abstracts continued the steady growth seen over the preceding decades, reaching about 2000 in the years 2008–2010, with a total of close to 4000 unique authors. This report, however, has its limitations and it is inherently incomplete, as it was prepared jointly by the members of the Organising Committee of Commission 10 (see the names of the primary contributors to the sections indicated in parentheses) reflecting their fields of expertise and interest. Nevertheless, we believe that it is a representative sample of significant new results obtained during the last triennium in the field of solar activity.

The chemical composition of a protoplanetary disk is determined not only by in situ chemical processes during the disk phase, but also by the history of the gas and dust before it accreted from the natal envelope. In order to understand the disk's chemical composition at the time of planet formation, especially in the midplane, one has to go back in time and retrace the chemistry to the molecular cloud that collapsed to form the disk and the central star. Here we present a new astrochemical model that aims to do just that. The model follows the core collapse and disk formation in two dimensions, which turns out to be a critical upgrade over older collapse models. We predict chemical stratification in the disk due to different physical conditions encountered along different streamlines. We argue that the disk-envelope accretion shock does not play a significant role for the material in the disk at the end of the collapse phase. Finally, our model suggests that complex organic species are formed on the grain surfaces at temperatures of 20 to 40 K, rather than in the gas phase in the T > 100 K hot corino.

While celebrating the International Year of Astronomy 2009, some government and private institutions in Bolivia pointed out the need to raise a petition to UNESCO and the IAU aimed at declaring the monument known as ‘La Horca del Inca’ (The Inca's Gallows) to be an astronomical World Heritage Site. The request was made because La Horca del Inca was assumed to be a pre-Columbian astronomical observatory. In this paper we analyze the reliability of that postulate through a twofold approach: 1) by examining the most relevant publications, both archaeological and astronomical, that conclude that the site was indeed a pre-Columbian astronomical observatory; and 2) by independently visiting and surveying the monument and its surrounding area.

The prospects are described for studies of large samples of supernovæ and other variable objects with two proposed future facilities: (1) the European Extremely Large Telescope, a general-purpose 40-m-class ground-based optical-IR telescope, and (2) Euclid, an M-class mission within ESA's Cosmic Vision programme, primarily for cosmology. The capabilities and status of the two facilities are briefly described. Their suitability for the study of time-varying objects in general, and of supernovæ in particular, is discussed. It is shown that Euclid has the potential for NIR imaging of a few thousand Type Ia supernovæ to intermediate z, while the E-ELT will be capable of spectroscopic and classification measurements of Type Ia supernovæ to z=4.

It has been observed that the ratio of Hα to FUV luminosity (LHα/LFUV) is lower in low surface brightness galaxies. This behaviour has been attributed to systematic variations of the upper mass end and/or the slope of the Initial Mass Function (IMF) Meurer et al. (2009) and Lee et al. (2009)). However these hypotheses do not explain the observed scatter in luminosity ratio (LHα/LFUV). We present a model for the total LHα and LFUV luminosity arising from a randomly populated IMF following the Salpeter power law and the clustering law of Oey & Clarke (2007).

Commission 12 of the International Astronomical Union encompasses investigations of the internal structure and dynamics of the Sun, mostly accessible through the techniques of local and global helioseismology, the quiet solar atmosphere, solar radiation and its variability, and the nature of relatively stable magnetic structures like sunspots, faculae and the magnetic network. The Commission sees participation of over 350 scientists worldwide.

The topology of the large-scale magnetic field of the Sun and its role in the development of magnetic activity were investigated using Hα charts of the Sun in the period 1887-2011. We have considered the indices characterizing the minimum activity epoch, according to the data of large-scale magnetic fields. Such indices include: dipole-octopole index, area and average latitude of the field with dominant polarity in each hemisphere and others. We studied the correlation between these indices and the amplitude of the following sunspot cycle, and the relation between the duration of the cycle of large-scale magnetic fields and the duration of the sunspot cycle.

The comparative analysis of the solar corona during the minimum epochs in activity cycles 12 to 24 shows that the large-scale magnetic field has been slow and steadily changing during the past 130 years. The reasons for the variations in the solar coronal structure and its relation with long-term variations in the geomagnetic indices, solar wind and Gleissberg cycle are discussed.

We also discuss the origin of the large-scale magnetic field. Perhaps the large-scale field leads to the generation of small-scale bipolar ephemeral regions, which in turn support the large-scale field. The existence of two dynamos: a dynamo of sunspots and a surface dynamo can explain phenomena such as long periods of sunspot minima, permanent dynamo in stars and the geomagnetic field.

The spectrum of strongly interacting binaries, as for example, high and low mass X-ray binaries, symbiotic (X-ray) binaries and/or classical and recurrent novae, consists of more components of radiation contributing from hard X-rays to radio wavelengths. To understand the basic physical processes responsible for the observed spectrum we have to disentangle the composite spectrum into its individual components, i.e. to determine their physical parameters. In this short contribution I demonstrate the method of modeling the multiwavelength SED on the example of the extragalactic super-soft X-ray source RX J0059.1-7505 (LIN 358).

In this essay we present a tentative archaeoastronomical analysis of the Moxos' Lagoons, a controversial and huge geographical network in the landscape of the Bolivian Amazon. In the late 1990s, a preliminary analysis of the orientation of a comprehensive and statistically significant number of lagoons showed that only human action could explain the peculiarities of their geometry, and especially their orientation according to a main axis aligned to an azimuth of 50° and its complementary angle. Since then, there has been an open debate on how these orientations could have been determined in practice. The absence of distinctive geographical features on the horizon strongly suggests that this peculiar pattern must have an astronomical justification. This short report presents a first approximation to the problem, suggesting that the lagoons could have been deliberately orientated in accordance with certain stellar positions which may have marked selected moments in the local climatic or economic cycle, a fact that could be corroborated by ethnohistoric references. The implications for new ethnographical research in the region are self-evident.

Angular momentum transport plays an important role in mass transfer systems, and can significantly spin up an accreting star. When the accretor is a white dwarf (WD) on its way to becoming a Type Ia supernova (SN Ia), the spin up of the WD can have significant consequences for the appearance of the progenitor, the characteristics of the explosion and its aftermath, the geometry of the supernova remnant, and for single-degenerate models, the appearance of the donor star post-explosion. These consequences can be “game changers”, altering results that have long been taken for granted. We discuss key features of our spin-up/spin-down models and their implications. We relate our models to work still needed to address the difficult physical issues related to angular momentum transport and its effects on the properties and appearance of Type Ia supernova progenitors.

The infrared spectra of many galactic and extragalactic objects are dominated by emission features at 3.3, 6.2, 7.7, 8.6 and 11.2 μm. The carriers of these features remained a mystery for almost a decade, hence the bands were dubbed the unidentified infrared (UIR) bands. Since the mid-80's, the UIR bands are generally attributed to the IR fluorescence of Polycyclic Aromatic Hydrocarbon molecules (PAHs) upon absorption of UV photons – the PAH hypothesis. Here we review the progress made over the past 25 years in understanding the UIR bands and their carriers.

This paper summarizes a search for radio-wavelength counterparts to candidate gravitational-wave events. The identification of an electromagnetic counterpart could provide a more complete understanding of a gravitational-wave event, including such characteristics as the location and the nature of the progenitor. We used the Expanded Very Large Array (EVLA) to search six galaxies which were identified as potential hosts for two candidate gravitational-wave events. We summarize our procedures and discuss preliminary results.

It is important to properly describe the mass-loss rate of AGB stars, in order to understand their evolution from the AGB to PN phase. The primary goal of this study is to investigate the influence of metallicity on the mass-loss rate, under well determined luminosities. The luminosity of the star is a crucial parameter for the radiative driven stellar wind. Many efforts have been invested to constrain the AGB mass-loss rate, but most of the previous studies use Galactic objects, which have poorly known distances, thus their luminosities. To overcome this problem, we have studied mass loss from AGB stars in the Galaxies of the Local Group. The distance to the stars have been independently measured, thus AGB stars in these galaxies are ideal for understanding the mass-loss rate. Moreover, these galaxies have a lower metallicity than the Milky Way, providing an ideal target to study the influence of metallicity on the mass-loss rate. We report our analysis of mass loss, using the Spitzer Space Telescope and the Herschel Space Observatory. We will discuss the influence of AGB mass-loss on stellar evolution, and explore AGB and PN contribution to the lifecycle of matter in galaxies.

The GRB-SNe connection has been strengthened since 2008 by the detection of 6 additional GRB-SNe at both local and cosmological redshifts. This review summarizes the recent observations of SNe associated with GRBs 081007, 090618, 091127, 100316D, 101219B and 111211A, as well as the observations of SN 2008D, which was associated with a bright X-ray flash (XRF 080109) and may represent a link between “plain” SN and GRB-SNe. It is now clear that most – if not all – long-duration GRBs are produced by the core collapse of massive stars.