The fate of massive stars up to 300M⊙ is highly uncertain. Do these objects produce pair-instability explosions, or normal Type Ic supernovae? In order to address these questions, we need to know their mass-loss rates during their lives. Here we present mass-loss predictions for very massive stars (VMS) in the range of 60-300M⊙. We use a novel method that simultaneously predicts the wind terminal velocities v∞ and mass-loss rate Ṁ as a function of the stellar parameters: (i) luminosity/mass Γ, (ii) metallicity Z, and (iii) effective temperature Teff. Using our results, we evaluate the likely outcomes for the most massive stars.

Based on the database of 56 supernovae (SNe) events discovered in 3838 galaxies of the southern hemisphere, we compute the rate of SNe of different types along the Hubble sequence normalized to the optical and near-infrared (NIR) luminosities as well as to the stellar mass of the galaxies. We find that the rates of Type Ia SNe show a dependence on both morphology and colors of the galaxies, and therefore, on the star-formation activity. The rate of SNe Ia can be explained by assuming that at least 15% of Ia events in spiral galaxies originate in relatively young stellar populations. We also find that the rates show no modulation with nuclear activity or environment.

During the last 10 years we have seen a revolution in the quality and quantity of data for time-series photometry. The two satellites MOST and WIRE were the precursors for dedicated time-series missions. CoRoT (launched in 2006) has now observed more than 100,000 targets for exoplanet studies and a few hundred stars for asteroseismology, while Kepler (launched in 2009) is producing extended time-series data for years, aiming to discover Earth-size planets in or near the habitable zone. We discuss the accuracy of some of the parameters one may extract from the high-quality data from such photometric space missions, including the prospects for detecting oscillation-period changes due to real-time stellar evolution.

Among the Western Tobas of the province of Formosa, Argentina, the asterism called Dapi'chi (the Pleiades) is highly important. Traditionally, it is related to the start of the annual cycle and it is also a very significant figure in terms of its symbolic meaning. In fact, this celestial representation offers a range of insights connected to winter frosts, a type of air carnation (Tillandsia spp.–Bromeliaceae) and also to the role of the warrior.

Two upcoming large scale surveys, the ESA Gaia and LSST projects, will bring a new era in astronomy. The number of binary systems that will be observed and detected by these projects is enormous, estimations range from millions for Gaia to several tens of millions for LSST. We review some tools that should be developed and also what can be gained from these missions on the subject of binaries and exoplanets from the astrometry, photometry, radial velocity and their alert systems.

We highlight and discuss the importance of accounting for nebular emission in the SEDs of high redshift galaxies, as lines and continuum emission can contribute significantly or subtly to broad-band photometry. Physical parameters such as the galaxy age, mass, star-formation rate, dust attenuation and others inferred from SED fits can be affected to different extent by the treatment of nebular emission.

We analyse a large sample of Lyman break galaxies from z ~ 3–6, and show some main results illustrating e.g. the importance of nebular emission for determinations of the mass–SFR relation, attenuation and age. We suggest that a fairly large scatter in such relations could be intrinsic. We find that the majority of objects (~ 60–70%) is better fit with SEDs accounting for nebular emission; the remaining galaxies are found to show relatively weak or no emission lines. Our modeling, and supporting empirical evidence, suggests the existence of two categories of galaxies, “starbursts” and “post-starbursts” (lower SFR and older galaxies) among the LBG population, and relatively short star-formation timescales.

Low-mass star forming regions are rich inventories of complex organic molecules. Furthermore, they show significant chemical diversity even among sources in a similar physical evolutionary stage (i.e. Class 0 sources). One distinct case is the hot corino chemistry characterized by rich existence of saturated complex organic molecules such as HCOOCH3 and C2H5CN, whereas the other is the warm carbon-chain chemistry (WCCC) characterized by extraordinary richness of unsaturated complex organic molecules such as carbon-chain molecules. We here summarize these observational achievements during the last decade, and present a unified picture of carbon chemistry in low-mass protostellar cores. The chemical diversity most likely originates from the source-to-source difference in chemical compositions of grain mantles. In particular, the gas-phase abundance of CH4 evaporated from grain mantles is thought to be a key factor for appearance of WCCC. The origin of the diversity and its evolution to protopranetary disks are discussed.

A sample of ~150 compact Galactic PNe has been observed with the Spitzer/IRS spectrograph to characterize their dust properties. These PNe are likely to be at the onset of the PN evolutionary phase, and are therefore ideal for probing dust evolution. The molecular emission features in these Galactic PN spectra are similar to those found in our Magellanic Cloud sample, except that we found a sizable fraction of PNe with mixed-chemistry dust which are not observed in the Clouds. We also found that the distribution among dust types depends strongly on the metallicity of the parent population, implying that the metallicity of the progenitors affects the evolution of a PN from its early stages.

Gaia is continuing well with its development and construction and is expected to achieve parallax accuracies of about 10 to 300 μas for 6 to 20 mag. It is scheduled to launch in 2013.

The ICRF2 was adopted by the IAU in 2009 as the new fundamental celestial reference frame.

The UCAC project concluded with the publication of its 4th data release (all-sky, over 100 million stars).

The JASMINE project will launch the Nano-JASMINE satellite in 2012 and continues with the development of its other satellites which will complement the Gaia project.

The PPMXL (Heidelberg) and XPM (Ukraine) catalogues provide improved astrometric accuracies from new reductions of USNO-B (USNO-A) and 2MASS data.

It is disappointing that the SIM project was cancelled during this triennium. It would have further complemented the above two satellite projects and would have gone even beyond Gaia in astrometric accuracy.

Magnetic helicity fluxes in turbulently driven α2 dynamos are studied to demonstrate their ability to alleviate catastrophic quenching. A one-dimensional mean-field formalism is used to achieve magnetic Reynolds numbers of the order of 105. We study both diffusive magnetic helicity fluxes through the mid-plane as well as those resulting from the recently proposed alternate dynamic quenching formalism. By adding shear we make a parameter scan for the critical values of the shear and forcing parameters for which dynamo action occurs. For this αΩ dynamo we find that the preferred mode is antisymmetric about the mid-plane. This is also verified in 3-D direct numerical simulations.

We present R-Band light curves of Type II supernovae (SNe) from the Caltech Core Collapse Program (CCCP). With the exception of interacting (Type IIn) SNe and rare events with long rise times, we find that most light curve shapes belong to one of three distinct classes: plateau, slowly declining and rapidly declining events. The latter class is composed solely of Type IIb SNe which present similar light curve shapes to those of SNe Ib, suggesting, perhaps, similar progenitor channels. We do not find any intermediate light curves, implying that these subclasses are unlikely to reflect variance of continuous parameters, but rather might result from physically distinct progenitor systems, strengthening the suggestion of a binary origin for at least some stripped SNe. We find a large plateau luminosity range for SNe IIP, while the plateau lengths seem rather uniform at approximately 100 days. We present also host galaxy trends from the Palomar Transien Factory (PTF) core collapse SN sample, which augment some of the photometric results.

This paper focuses on the Ticuna interpretation of the iconography inscribed on ritual artifacts collected by the ethnographer Curt Nimuendaju in the early 1940s. The Ticuna describe certain celestial bodies depicted in the iconography of artifacts that are used in the Ticuna girls' puberty festival as ‘Worecü stars’. They relate these stars to various aspects of indigenous mythology expressed in ritual songs and speeches about worecü, a Ticuna word meaning the girl for whom the initiation is being performed. I hold that by incorporating Ticuna mediations into anthropological analysis we enrich this analysis by associating iconic images with mythical meanings transmitted generation by generation through ritual performances in which mythical thinking has the persuasive force of prescriptive action. In thinking about how the Ticuna read the iconography I avoid seeking a strict correlation between Western scientific explanations and the Ticuna's own knowledge about a special star known by them as the Woramacüri star. However, by postulating an association between the Worecü stars and the planets, we can examine the possibility that the Woramacüri Star is correlated with a particular planet at certain times, in specific circumstances.

Herschel, an ESA space observatory equipped with science instruments provided by European-led Principal Investigator consortia with important participation from NASA, was launched on 14 May 2009. With its 3.5m diameter primary mirror, Herschel is the largest space telescope ever launched into space, and carries onboard three science instruments, whose focal plane units are cryogenically cooled inside a superfluid helium cryostat. The PACS and SPIRE instruments provide broadband imaging photometry in six bands centred at 75, 100, 160, 250, 350, and 500 microns and imaging spectroscopy over the range 55–672 microns. The HIFI instrument provides very high-resolution heterodyne spectroscopy over the ranges 157–212 and 240–625 microns. The results obtained already in the first year and a half of routine science operations demonstrate that Herschel will have strong impact on all research fields, from Solar System studies to the area of Cosmology, from the analysis of star formation to the mysteries of galaxy formation. In this talk I will review the Herschel highlights in the area of evolved stars in general and of planetary nebulae more in particular, resulting from observations performed with the three instruments onboard Herschel since launch. This will be exemplified by a few observational results, just the tip of the iceberg of what is yet to come in the remaining year and a half of science operations.

Stellar magnetic fields are produced by a magnetohydrodynamic dynamo mechanism working in their interior – which relies on the interaction between plasma flows and magnetic fields. The Sun, being a well-observed star, offers an unique opportunity to test theoretical ideas and models of stellar magnetic field generation. Solar magnetic fields produce sunspots, whose number increases and decreases with a 11 year periodicity – giving rise to what is known as the solar cycle. Dynamo models of the solar cycle seek to understand its origin, variation and evolution with time. In this review, I summarize observations of the solar cycle and describe theoretical ideas and kinematic dynamo modeling efforts to address its origin. I end with a discussion on the future of solar cycle modeling – emphasizing the importance of a close synergy between observational data assimilation, kinematic dynamo models and full magnetohydrodynamic models of the solar interior.

We present NBursts+phot, a novel technique for the parametric inversion of spectrophotometric data for unresolved stellar populations where high-resolution spectra and broadband SEDs are fitted simultaneously, helping to break the degeneracies between parameters of multi-component stellar population models.

The CoRoT and Kepler space missions have opened a new era in eclipsing binary research. While specifically designed for exoplanet search, they offer as by-products the discovery and monitoring of variable stars, in great majority eclipsing binaries (EB). The missions are therefore providing thousands of EB light curves of unprecedented accuracy (typically a few hundred parts per million, ppm), with regular sampling (from 1s to 29m), extending over time spans of months, and with a very high duty cycle (>90%).

Thanks to this excellent photometry, research topics as asteroseismology of EB components are quickly developing, and physical phenomena such as doppler boosting, theoretically predicted but extremely difficult to observe from the ground, have been unambiguously detected. We present the main properties of the Corot and Kepler EB samples and briefly review the highlights of the missions in this field.

The Commission supports and coordinates scientific investigations about Earth rotation and related reference frames. Above all C19 encourages and develops cooperation and collaboration in observation and theoretical studies of Earth orientation (the motions of the pole in the terrestrial and celestial reference systems and the rotation about the pole). The Commission serves the astronomical community by linking it to the official organizations providing the International Terrestrial and Celestial Reference Systems/Frames (ITRS/ITRF and ICRS/ICRF) and Earth orientation parameters (EOP): International Association of Geodesy (IAG), International Earth Rotation and Reference System Service (IERS), International VLBI Service for Geodesy and Astrometry (IVS), International GNSS Service (IGS), International Laser Ranging Service (ILRS), International DORIS Service (IDS). Among the most important activities are the development of methods for improving the accuracy and understanding of Earth orientation and related reference systems/frames. Further, C19 ensures the agreement and continuity of the reference frames used for Earth orientation with other astronomical reference frames and their densifications and provides means of comparing observational and analysis methods and results to ensure accuracy of data and models.

The nature and timescales behind the growth of the white dwarf toward the Chandrasekhar mass are not known. The two leading competing scenarios for Type Ia supernovae (SNe Ia) are accretion from a companion [single degenerate (SD)] or merger with another white dwarf [double degenerate (DD)]. Measurement of the SNe Ia delay time distribution could distinguish between these scenarios. Possibly both channels operate, on short (SD) and long (DD) time scales. A supernova search in parallel with our Cluster Lensing And Supernova survey with Hubble extends the Hubble diagram of SNe Ia to z > 1.5, probing progenitor evolution and testing the constancy of dark energy (DE) with time. We use HST ACS to detect SNe Ia at 1 < z < 1.5 and WFC3 to find SNe Ia at 1.5 < z < 2.5, thus providing constraints for the variation in the DE equation of state. This redshift epoch provides the unique chance to test SNe Ia distance measurements for the deleterious effects of evolution independent of our ignorance of dark energy. Our program provides the first measurement of the SNe Ia rate at z ~ 2.

The last 20 years have seen revolutionary developments of large-scale synoptic surveys of the sky, both from the ground (e.g., the MACHO and OGLE projects, which were targetted at micro-lensing studies) and in space (e.g., the X-ray All-Sky Monitor onboard RXTE). These utilised small and medium-sized telescopes to search for transient-like events, but they have now built up a huge database of long-term light-curves, thereby enabling archival research on a wide range of objects that has not been possible hitherto. This is illustrated with examples of long time-scale optical and X-ray variability studies from the field of X-ray binary research: the high-mass BeX binaries in the SMC (using MACHO and OGLE), and the bright galactic-bulge X-ray sources (mostly LMXBs, using RXTE/ASM). As such facilities develop greater capabilities in future and at other wavelengths (developments in South Africa will be described), real-time data processing will allow much more rapid follow-up studies with the new generation of queue-scheduled large telescopes such as SALT.

With the advances in high angular resolution (sub)millimeter observations of low-mass protostars, windows of opportunities are opening up for very detailed studies of the molecular structure of star forming regions on wide range of spatial scales. Deeply embedded protostars provide an important laboratory to study the chemistry of star formation – providing the link between dense regions in molecular clouds from which stars are formed, i.e., the initial conditions and the end product in terms of, e.g., disk and planet formation. High angular resolution observations at (sub)millimeter wavelengths provide an important tool for studying the chemical composition of such low-mass protostars. They for example constrain the spatial molecular abundance variations – and can thereby identify which species are useful tracers of different components of the protostars at different evolutionary stages. In this review I discuss the possibilities and limitations of using high angular resolution (sub)millimeter interferometric observations for studying the chemical evolution of low-mass protostars – with a particular keen eye toward near-future ALMA observations.