This poster reported our spectroscopy of the neutron-star X-ray binary 4U 1728-34, observed with Suzaku in 2010 October. It is classified as an atoll source. Its continuous X-ray spectrum can be fitted by a combination of a multicolour accretion-disk model for the soft energy, plus a power-law model for the hard energy. A broad emission line at 6–7 keV can be fitted well using a simple Gaussian component with an equivalent width of ∼322 eV. However, for this object the presence of that feature is disputed, even though our results from Suzaku do suggest the presence of a broad Fe emission line that is consistent with results from XMM-Newton. Nevertheless, the parameters of the line (the line centroid and the equivalent width) are a little different, but that could be due to a difference in modelling the continuum.

We investigate whether the globular clusters 47 Tuc, ω Cen and NGC 6624 contain intermediate-mass black holes (IMBHs) by fitting a large grid of N-body simulations against their surface density and velocity dispersion profiles. In our simulations we vary the initial cluster size, the initial mass function and the initial density profile of the clusters as well as the mass fraction of a central intermediate-mass black hole. We find that the surface density and velocity dispersion profiles of all three clusters can be better reproduced by models that do not contain a central IMBH than by any of our IMBH models. If ω Cen and NGC 6624 contain any IMBHs at all, they have to be significantly less massive than suggested in the past.

Properties of dwarf galaxies formed and evolved in the lowest density environment remain largely unexplored and poorly understood. Especially this concerns the low-mass end (Mbar < 109M⊙). We overview the results of systematic study of a hundred void dwarfs from the nearby Lynx-Cancer void. We describe the ongoing project aiming to form Nearby Void galaxy sample (R < 25 Mpc) over the whole sky. 1354 objects with distances less than 25 Mpc fall within 25 voids delineated by 460 luminous galaxies/groups. The void major sizes range from 13 to 37 Mpc. 1088 of 1354 void galaxies reside deeply in voids, having distances to the nearest luminous neighbour of 2–11 Mpc. 195 nearest void galaxies reside in the Local Volume. We summarize the main statistical properties of the new sample and outline the prospects of study of both, the void dwarf properties and the fine structure of voids.

We have been investigating populations of cataclysmic variables (CVs) in a set of more than 300 globular cluster (GC) models evolved with themoccacode.[-120pt] One of the main questions we have intended to answer is whether most CVs in GCs are dynamically formed or not. Contrary to what has been argued for a long time, we found that dynamical destruction of primordial CV progenitors is much stronger in GCs than dynamical formation of CVs. In particular, we found that, on average, the detectable CV population is predominantly composed of CVs formed via a typical common envelope phase (≳70 per cent). However, core-collapsed models tend to have higher fractions of bright CVs than non-core-collapsed ones, which suggests then that the formation of CVs is indeed slightly favoured through strong dynamical interactions in core-collapsed GCs, due to the high stellar densities in their cores.

There is a strong correlation between coronal mass ejection transients and chromospheric H-α activity. Solar physicists hope to ascertain what causes coronal disturbances, and in our current investigation we are trying to address that problem by assessing the likelihood that a coronal disturbance is associated with other manifestations of the same abrupt, perturbing event such as a flare. The correlation, if any, between filament and flare can be derived by a method of image processing. Our next approach is to give the results of statistical research by studying a century of chromospheric Hα observations. This poster describes the concept and preliminary experiences of deriving the characteristics of a filament and a flare.

This poster paper described initial results of recent meteor observations in Kazan obtained with a new meteor radar, SKiYMET. Significant improvements in the number of registrations are being recorded, enabling better statistics.

Radar observations of meteors have been carried out and archived since the mid-20th Century; at Kazan University (56°N, 49°E) they commenced in 1956, and have continued with only a few interruptions. A quasi-tomographic method (developed in-house in 2000) has been used to determine the coordinates of radiants of meteor showers, and to derive the orbital elements of small showers (microshowers).

The observations provide valuable information about the distribution of meteoric matter near the Earth’s orbit. That information supports studies of stratospheric temperatures. A new radar, SKiYMET, was deployed in 2015 and measured parameters such as meteor speeds, but in 2016 its software was supplemented by an in-house package which performed more efficient pre-filtering of the primary data to eliminate non-meteor reflections from various sources. The new filtering algorithm has reduced substantially the threshold S/N ratio for detecting meteors (so fainter meteors can now be recorded), while the package also enables meteor velocities to be calculated much more efficiently than with SKiYMET, improving significantly the quality and statistical indicators of the processed data. By detecting a much larger number of meteors, it enables more detailed studies of the distribution of meteor velocities per day and per season.

Daily meteor counts for 2016–2017, extracted from the observations by the KFU programme, yielded significantly higher rates than with SKiYMET. These results support much better statistics, and also enable much finer details to be discerned. In particular, plots of meteor rates against speed are found to exhibit two maxima, one near 30 km s−1 and one near 55 km s−1. This bifurcation in the relationship can also be discerned in the seasonal dependences of the speed distribution.

Improvements in the measurements of the speeds of meteor particles entering the atmosphere reveal an increase in the numbers with higher speeds (> 50 km s−1). The distributions of speeds and heights show a rather strong dependence of the meteor speed upon altitude; as predicted by meteor physics, those with higher speeds begin to burn at higher altitudes. A local increase in the number of meteors that have speeds of about 55 km s−1 has also been reported in the literature. The increase could be associated with heterogeneities in the distribution of meteoric matter in the vicinity of the Earth’s orbit.

Half-dozen of extreme representatives of void dwarf galaxy population were found in our study of evolutionary status of a hundred galaxies in the nearby Lynx-Cancer void. They are very gas-rich, extremely low-metallicity [7.0 < 12 + log(O/H) < ∼ 7.3] objects, with blue colours of outer parts. The colours indicate the ages of the oldest visible stellar population of one to a few Gyr. They all are intrinsically faint, mostly Low Surface Brightness dwarfs, with MB range of –9.5m to –14m. Thus, their finding is a subject of the severe observational selection. The recent advancement in search for such objects in other nearby voids resulted in doubled their total number. We summarize all available data on this group of unusual void dwarf galaxies and discuss them in the general context of very low metallicity galaxies and their possible formation and evolutionary scenarios.

We carried out a high contrast imaging search for (sub)stellar companions of young pre-main sequence stars in the Lupus star forming region. For this project we utilized NACO/ESO-VLT, operated at the Paranal observatory. On this poster, we presented the results of this survey. In several observing campaigns we could obtain diffraction limited deep IR imaging data and detected faint co-moving companions around our targets, whose astro- and photometry was determined in all observing epochs. The co-moving companions found in our survey exhibit angular separations in the range between about 0.1 and a few arcsecs, i.e. projected separations between about 10 and a few hundreds of au, at the average distance of our targets of about 140 pc. Beside several new binary and triple star systems, whose multiplicity was revealed in this survey, also faint co-moving companions in the substellar mass regime could be identified close to some of our targets.

We have been intensely monitoring photometric variability in proto-planetary nebulae (PPNe) over the past 25 years and radial velocity variability over the past ten years. Pulsational variability has been obvious, in both the light and velocity, although the resulting curves are complex, with multiple periods and varying amplitudes. Observed periods range from 25 to 160 days, and the periods and amplitudes reveal evolutionary trends. We will present our observational results to date for approximately 30 PPNe, and discuss these results, including the search for period changes that might help constrain post-AGB evolutionary timescales.

Having disk-to-star accretion rates on the order of 10-4M⊙/yr, FU Orionis-type stars (FUors) are thought to be the visible examples for episodic accretion. FUors are often surrounded by massive envelopes, which replenish the disk material and enable the disk to produce accretion outbursts. We observed the FUor-type star V346 Nor with ALMA at 1.3 mm continuum and in different CO rotational lines. We mapped the density and velocity structure of its envelope and analyzed the results using channel maps, position-velocity diagrams, and spectro-astrometric methods. We discovered a pseudo-disk and a Keplerian disk around a 0.1 M⊙ central star. We determined an infall rate from the envelope onto the disk of 6×10-6M⊙/yr, a factor of few higher than the quiescent accretion rate from the disk onto the star. This hints for a mismatch between the infall and accretion rates as the cause of the eruption.

A sample of 28 oxygen-rich evolved stars is selected based on the presence of crystalline silicate emission features in their ISO/SWS spectra. The crystallinity, measured as the flux fraction of crystalline silicate features, is found not to be related to mass loss rate that is derived from fitting the spectral energy distribution.

The advent of the Gaia mission is bringing astrometry to a new renaissance. Although Gaia will make important breakthroughs in many different scientific areas, stars in the crowded central fields of globular clusters (GCs) and at the faint end of the color-magnitude diagram are and will be out of Gaia’s reach. The Hubble Space Telescope (HST) is an excellent astrometric tool that has allowed us to distinguish and measure positions and brightness of faint stars in pencil-beam fields down to the very center of some GCs. Gaia and HST are two wonderful, complementary tools, but are yet far from being able to offer a complete dynamical picture of GCs. There is now great prefiguration for what the next-generation telescopes will be able to do, both ground- and space-based. This document highlights strengths and weaknesses of different facilities at different spatial and spectral regimes.

HR 6902 was the first target of a systematic study by Griffin (1986, JApA, 7, 195) of binaries showing composite spectra. It is also a well-studied member of the ζ Aur class. ζ Aur systems are long-period eclipsing binaries that are comprised of an evolved giant primary and a hot dwarf companion. Although those component stars have very different effective temperatures they have similar luminosities in the blue and near-UV regions, and hence display a composite spectrum at those wavelengths. In principle the ζ Aur systems are excellent tests of evolutionary and structural stellar models. In recent years the somewhat fragmentary eclipse photometry of HR 6902 has been out-classed by the high-precision continuous monitoring by the space mission CoRoT. HR 6902 was selected as a primary target of its seismology field, because the possible detection of solar-like pulsations in a giant component of a double-lined eclipsing binary could help to calibrate the scaling relation of giant pulsators. Our poster reported the results of a new analysis based on the CoRoT observations and follow-up spectroscopy with HARPS at the ESO 3.6-m telescope at La Silla.

The unprecedented accuracy of the CoRoT photometry enabled us to:

• improve drastically the accuracy of the binary orbit and stellar parameters (by a factor ~10 for the radii)

• extend the test of validity/calibration of the scaling relations to high stellar mass and radius, and put constraints on the evolutionary state (particularly since this binary is certainly free from tidal effects).

The 6th Focus Meeting (FM6) at the XXXth IAU GA 2018 aimed at overviewing the rise in angular momentum (AM) science seen in the last 10 years and debating new emerging views on galaxy evolution. The foundational works on galaxy formation of the 1970s and 80s clearly exposed the fundamental role of AM, suspected since the time of Kant. However, quantitative progress on galactic AM remained hampered by observational and theoretical obstacles. Only in the last 10 years, numerical simulations began to produce galactic disks with realistic AM. Simultaneously, the fast rise of Integral Field Spectroscopy (IFS) and millimetre/radio interferometry have opened the door for systematic AM measurements, across representative samples and cosmic volumes. The FM bridged between cutting-edge observational programs and leading simulations in order to review, debate and resolve core issues on AM science, ranging from galactic substructure (e.g. gas fraction, turbulence, clumps) to global properties (e.g. size evolution, morphologies) and cosmology (spin alignment, cosmic origin of AM). The co-chairs and SOC members strived to assemble a representative selection of leading scientists in the field, while adhering to principles of equal opportunity and inclusivity.

Based on radio and X-ray observations, it has been suggested that a black hole of mass ∼106 Mʘ resides in the dwarf starburst galaxy Henize 2-10. This unusual finding has important implications for the formation of massive black holes in the early universe since Henize 2-10 can be viewed as a low redshift analog to the first high-z galaxies. We present long-slit HST STIS spectra that include the central radio/X-ray source. While recent VLT-MUSE spectroscopic observations with 0″.7 seeing show no change in ionization near the central source, our higher spatial resolution STIS observations identify a distinct compact region at the location of the radio/X-ray source. Initial analysis reveals broader (FWHM ∼ 380 km s-1) blue-shifted lines of low ionization. Our analysis focuses on testing two scenarios: a LINER-like AGN and a young (few decades) SNR.

In the last decade great strides have been made in understanding the role of binary stars in the evolution and shaping of planetary nebulæ (PNe). Observational efforts have mainly focused on finding close binaries with orbital periods of 1 day or less. Those close binary systems make up around 1 in 5 PNe, and constitute the youngest accessible window into the aftermath of the critical and unobserved common-envelope (CE) phase of binary-star evolution. The poster focused on our recent work with the High Resolution Spectrograph (HRS) on the Southern African Large Telescope (SALT) to search for long-period binaries in PNe. Considerably less is known about such long-period binaries with orbital periods of weeks to years, but they may be fundamental to improving CE population synthesis models and for determining the total binary fraction of PNe. The queue-mode operation of SALT and the excellent sensitivity and stability of HRS (which is enclosed in a vacuum tank) are ideally suited to detecting binaries with low radial-velocity amplitudes over the expected timescales of weeks to years. Many exciting new discoveries about binaries have already been made in this newly-accessible southern horizon in time-domain astronomy thanks to the many unique advantages of SALT.

Angular momentum (AM) is a key parameter to understand galaxy formation and evolution. AM originates in tidal torques between proto-structures at turn around, and from this the specific AM is expected to scale as a power-law of slope 2/3 with mass. However, subsequent evolution re-shuffles this through matter accretion from filaments, mergers, star formation and feedback, secular evolution and AM exchange between baryons and dark matter. Outer parts of galaxies are essential to study since they retain most of the AM and the diagnostics of the evolution. Galaxy IFU surveys have recently provided a wealth of kinematical information in the local universe. In the future, we can expect more statistics in the outer parts, and evolution at high z, including atomic gas with SKA.

Binary evolution can produce different blue-straggler binaries, for example, blue stragglers with a bright, red component, or with a faint, blue component. In globular clusters, these blue-straggler binaries are generally observed as a single star, because two components can not be distinguished. Therefore, these blue-straggler binaries can be located in different regions of the color-magnitude diagram of globular clusters, e.g. blue sequence and red sequence observed in M30. We suggest that binary evolution can contribute to the blue stragglers in both of the sequences. Some blue stragglers in the blue sequence may have a faint white dwarf companion, while the red sequence includes some binaries experiencing mass transfer. It should be noted that the red sequence may also have other binaries, for example, the binaries just finished the mass transfer, and the binaries including a blue straggler (the accretors) that have evolved away from the blue sequence.

he study of the kinematics of globular clusters (GCs) offers the possibility of unveiling their long term evolution and uncovering their yet unknown formation mechanism. Gaia DR2 has strongly revitalized this field and enabled the exploration of the 6D phase-space properties of Milky Way GCs, thanks to precision astrometry. However, to fully leverage on the power of precision astrometry, a thorough investigations of the data is required. In this contribution, we show that the study of the mean radial proper motion profiles of GCs offers an ideal benchmark to assess the presence of systematics in crowded fields. Our work demonstrates that systematics in Gaia DR2 for the closest 14 GCs are below the random measurement errors, reaching a precision of ∼0.015 mas yr−1 for mean proper motion measurements. Finally, through the analysis of the tangential component of proper motions, we report the detection of internal rotation in a sample of ∼50 GCs, and outline the implications of the presence of angular momentum for the formation mechanism of proto-GC. This result gives the first taste of the unparalleled power of Gaia DR2 for GCs science, in preparation for the subsequent data releases.