Amongst the dwarf galaxies in the Local Group, the isolated irregular one, IC 10 is one of the most interesting galaxies, with strong star forming activity and the highest density of Wolf-Rayet stars. Undergoing a starburst phase, having numerous HII regions and being bright in all wavebands, makes it an exquisite galaxy to study the internal and external processes that continue to affect dwarf galaxies 14 Gyr since the Big Bang. In this study, we present a new deep and precise optical monitoring survey of IC 10 using the Isaac Newton Telescope (INT) with the wide field camera (WFC). We performed observations at nine epochs spaced between three to four months apart between 2015 and 2017. We identified Long Period Variable stars (LPVs), Asymptotic Giant Branch stars (AGBs) and Red Super Giant stars (RSGs) to determine the star formation history and chemical evolution of IC 10.

. A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading model for the physics governing this X-ray behaviour suggests that the winds of the donor OB supergiants are magnetized. In agreement with this model, the first spectropolarimetric observations of the SFXT IGR J11215-5952 using the FORS 2 instrument at the Very Large Telescope indicate the presence of a kG longitudinal magnetic field. Based on these results, it seems possible that the key difference between supergiant fast X-ray transients and other high-mass X-ray binaries are the properties of the supergiant’s stellar wind and the physics of the wind’s interaction with the neutron star magnetosphere.

The unidentified infrared (UIR) bands have been ubiquitously observed in various astrophysical environments and consist of a series of emission features arising from aromatic and/or aliphatic C-C and C-H bonds [1]. Therefore, their carriers are thought to be related to interstellar organics. However, our knowledge on the true carriers of the UIR bands is still limited. Recently [4] has proposed Mixed Aromatic Aliphatic Organic Nanoparticles, which contains hetero atoms in addition to conventional hydrocarbon models, as a more realistic interpretation of the band carriers. The challenges toward identifying the carriers of the UIR bands are still ongoing. Past studies have shown that the UIR bands observed around classical novae, which characterized by the presence of broad feature around 8μm[2], are somewhat different from those observed in other astrophysical environment. Here we report the success of experimentally synthesizing the organics called Nitrogen-included Carbonaceous Compounds (NCC; [7]) whose infrared properties can reproduce the UIR bands observed in classical novae.

The Office of Astronomy for Development (OAD) aims to use astronomy, including its tools, practitioners and skills, to benefit society. The OAD, a joint project of the International Astronomical Union and the South African National Research Foundation, has the vision of using ‘Astronomy for a better world’. Since 2013, the OAD has funded more than 120 projects that use astronomy to address developmental issues as defined under the United Nations Sustainable Development Goals (SDG).

The Virtual Observatory (VO) is an international astronomical community-based initiative. VO aims to allow global electronic access to the available astronomical data archives of space and ground-based observatories and other sky survey databases. VO for education is a project developed within the framework of the European Virtual Observatory (EuroVO) with the aim of diffusing VO data and software to the public, in particular students, teachers and astronomy enthusiasts. VO for education offers use cases, pedagogical units, and simplified professional software that will allow a taste of the emotion of scientific research even to those approaching astronomy for the first time or simply wishing to wander between stars.

We analyse the chemical abundances of stars in the local group dwarf galaxies using the SAGA database. The inspection of the relationship between Eu and Ba abundances confirms an anomalously Ba-rich population in Fornax, which indicates a pre-enrichment of interstellar gas with r-process elements.

Understanding Asymptotic Giant Branch (AGB) stars is important as they play a vital role in the chemical life cycle of galaxies. AGB stars are in a phase of their life time where they have almost ran out of fuel and are losing vast amounts of material to their surroundings, via stellar winds. As this is an evolutionary phase of low mass stars, almost all stars go through this phase making them one of the main contributors to the chemical enrichment of galaxies. It is therefore important to understand what kind of material is being lost by these stars, and how much and how fast. This work summarises the steps we have taken towards developing a self-consistent AGB wind model. We improve on current models by firstly coupling chemical and hydrodynamical evolution, and secondly by upgrading the nucleation theory framework to investigate the creation of TiO2, SiO, MgO, and Al2O3 clusters.

We search for possible differences in rotational frequencies, diameters, albedos, and orbital parameters between Trojans belonging to the L4 and L5 swarms using our own observations and literature data. With increasing number of observational data it becomes evident that the L4 and L5 populations have very similar distributions of most parameters with an exception of orbital inclination distribution.

Nitrogen is among the most abundant chemical elements in the cosmos, and asymptotic giant branch (AGB) stars are fundamental nucleosynthetic sources of N in galaxies. In this work, we show how the observed N/O versus O/H chemical abundance diagram, both in extragalactic systems and in our own Galaxy, can be used to constrain the nucleosynthetic origin of N in the cosmos. In particular, we review the results of our studies with chemical evolution models, embedded in full cosmological chemodynamical simulations.

Blazar observations point toward the possible presence of magnetic fields over intergalactic scales of the order of up to ∼1 Mpc, with strengths of at least ∼10−16 G. Understanding the origin of these large-scale magnetic fields is a challenge for modern astrophysics. Here we discuss the cosmological scenario, focussing on the following questions: (i) How and when was this magnetic field generated? (ii) How does it evolve during the expansion of the universe? (iii) Are the amplitude and statistical properties of this field such that they can explain the strengths and correlation lengths of observed magnetic fields? We also discuss the possibility of observing primordial turbulence through direct detection of stochastic gravitational waves in the mHz range accessible to LISA.

. The INTEGRAL satellite has revealed a previously hidden population of absorbed High Mass X-ray Binaries (HMXBs) hosting supergiant (SG) stars. Among them, IGR J16320–4751 is a classical system intrinsically obscured by its environment, with a column density of ~1023 cm-2, more than an order of magnitude higher than the interstellar absorption along the line of sight. It is composed of a neutron star (NS) rotating with a spin period of ~1300 s, accreting matter from the stellar wind of an O8I SG, with an orbital period of ~9 days. We analyzed all existing archival XMM- Newton and Swift/BAT observations of the obscured HMXB IGR J16320–4751 performing a detailed temporal and spectral analysis of the source along its orbit. Using a typical model for the supergiant wind profile, we simultaneously fitted the evolution of the hard X-ray emission and intrinsic column density along the full orbit of the NS around the SG, which allowed us to constrain physical and geometrical parameters of the binary system.

Magnetic fields play a key role in the early life of stars and their planets, as they form from collapsing dense cores that progressively flatten into large-scale accretion discs and eventually settle as young suns orbited by planetary systems. Pre-main-sequence phases, in which central protostars feed from surrounding planet-forming accretion discs, are especially crucial for understanding how worlds like our Solar System are born.

Magnetic fields of low-mass T Tauri stars (TTSs) are detected through high-resolution spectroscopy and spectropolarimetry (e.g., Johns Krull 2007), whereas their large-scale topologies can be inferred from time series of Zeeman signatures using tomographic techniques inspired from medical imaging (Donati & Landstreet 2009). Large-scale fields of TTSs are found to depend on the internal structure of the newborn star, allowing quantitative models of how TTSs magnetically interact with their inner accretion discs, and the impact of this interaction on the subsequent stellar evolution (e.g., Romanova et al. 2002, Zanni & Ferreira 2013).

With its high sensitivity to magnetic fields, SPIRou, the new near-infrared spectropolarimeter installed in 2018 at CFHT (Donati et al. 2018), should yield new advances in the field, especially for young embedded class-I protostars, thereby bridging the gap with radio observations.

Luminosity outbursts of the FU Ori type stars, which have a magnitude of ∼ 100 L⊙ and last for decades, may affect chemical composition of the surrounding protoplanetary disk. Using astrochemical modelling we analyse the changes induced by the outburst and search for species sensitive to the luminosity rise. Some changes in the disk molecular composition appear not only during the outburst itself but can also retain for decades after the end of the outburst. We analyse main chemical processes responsible for these effects and assess timescales at which chemically inert species return to the pre-outburst abundances.

Variability due to stellar pulsation on the Asymptotic Giant Branch (AGB) has a great potential for applications such as distance measurements, the study the evolution of stars and galaxies, and the estimate of global stellar parameters, as well as to constrain stellar evolutionary models. Given the importance of long-period variables (LPVs) in this sense, and given the lack of recent, updated sets of pulsation models, we computed an extended grid of pulsation models widely covering the space of AGB stellar parameters, including up-to-date opacities and accounting for the chemical evolution associated with third dredge-up events. We present the relevant properties of this grid and discuss the main results it allowed to obtain in terms of the interpretation of the observed properties of LPVs in the Large Magellanic Cloud (LMC).

This paper brings together the chief points raised during FM5 by astronomers, archaeologists, and historians whose research interests centred on novæ and supernovæ. The common focus was the use of historical observations to study transient astronomical phenomena. The presenters covered a wide variety of topics within that theme, and this report summarizes some of the aspects specific to historical novæ and supernovæ.

Understanding the effect of environment on galaxy formation and evolution is one of the hot topics in extragalactic astronomy. Here we constructed a chemical evolution model of disk galaxies. By comparing the model predictions with the observed profiles, we investigated the star formation history of M33, NGC 300 and NGC 2403. We found that M33 has much longer infall timescale than NGC 300 and NGC 2403, and the star formation process of M33 is still active at later phase. Our results suggested that the cold gas supply of M33 is sufficient in the present-day, which may originate from the HI bridge between M33 and M31. In other words, we argue that the local environment plays an important role on the star formation history of a galaxy, at least for M33.

Planet formation takes place in the gaseous and dusty disks that surround young stars, known as protoplanetary disks. With the advent of sensitive observations and together with developments in theory, our field is making rapid progress in understanding how the evolution of protoplanetary disks takes place, from its inception to the end result of a fully-formed planetary system. In this review, I discuss how observations that trace both the dust and gas components of these systems inform us about their evolution, mass budget, and chemistry. Particularly, the process of disk evolution and planet formation will leave an imprint on the distribution of solid particles at different locations in a protoplanetary disk, and I focus on recent observational results at high angular resolution in the sub-millimeter regime, which have revealed a variety of substructures present in these objects.

. We analyzed a 40-year set of multicolor photometry and a 15-year set of synoptic monitoring of SS 433 along with fragmentary spectral and radio data. This system contains a neutron star and an A3–A7 I giant. The system is found to be either close, in contact, or it has a common envelope from time to time. The A-type giant is now in transition to the dynamical mass transfer.