We present continuation of the multi-wavelength (from X-ray to optical) monitoring of the nearby changing look (CL) active galactic nucleus in the galaxy NGC 1566 performed with the Neil Gehrels Swift Observatory,the MASTER Global Robotic Network over the period 2007–2019. We also present continuation of optical spectroscopy using the South African Astronomical Observatory 1.9-m telescope between Aug. 2018 and Mar. 2019. We investigate remarkable re-brightenings in of the light curve following the decline from the bright phase observed at Dec. 2018 and at the end of May 2019. For the last optical spectra (31 Nov. 2018–28 Mar. 2019) we see dramatic changes compared to 2 Aug. 2018, accompanied by the fading of broad emission lines and high-ionization [FeX]6374Å line. Effectively, one more CL was observed for this object: changing from Sy1.2 to the low state as Sy 1.8–Sy1.9 type. Some possible explanations of the observed CL are discussed.

Cyclopropenylidene,, is a simple hydrocarbon, ubiquitous in astrophysical gases, and possessing a permanent electric dipole moment. Its readily observed multifrequency rotational transitions make it an excellent probe for the physics and history of interstellar matter. The collisional properties of with He are presented here. We computed the full Potential Energy Surfaces, and we perform quantum scattering in order to provide rates of quenching and excitation for low to medium temperature regimes. We discuss issues with the validity of the usual Local Thermodynamical Equilibrium assumption, and also the intricacies of the spectroscopy of an asymmetric top. We present the wide range of actual critical densities, as recently observed.

Together with the stellar rotation, the spotted surfaces of low-mass magnetically active stars produce modulations in their brightness. These modulations can be resolved by photometric variability surveys, allowing direct measurements of stellar spin rates. In this proceedings, we present results of a multisite photometric survey dedicated to the measurement of spin rates in the 30 Myr cluster NGC 3766. Inside the framework of the Monitor Project, the cluster was monitored during 2014 in the i-band by the Wide Field Imager at the MPG/ESO 2.2-m telescope. Data from Gaia-DR2 and grizY photometry from DECam/CTIO were used to identify cluster members. We present spin rates measured for ⁓200 cluster members.

Ibn al-Haytham (known as Alhazen in occident), extensively studied the camera obscura phenomenon in the early 11th century. This instrument was used to obtain the projected image of a landscape on the screen and also was addopte by the scientists and famous painters along the centuries, to experiment with it until their final evolution as the modern photografic camera. The resource in the simple version of the “pinhole camera” can be used at the classroom to experience several phenomena, such us solar eclipses and Moon phases, and to each about optics and geometry. This contribution presents an application of this ingeniuos tool in the framework of solar eclipses, where the scale models are important to understand what really happens with the Sun-Earth-Moon system.

Empirically characterizing the spectral evolution of cool white dwarfs is a prerequisite to understanding the physical processes that shape the evolution of these old objects. However, the high photospheric densities of cool helium-rich atmospheres seriously complicate the study of those stars. We have recently developed an updated atmosphere code that is appropriate for high densities and that can model any cool white dwarf (including DZs and DQpecs). Here, we present recent advances in our understanding of the spectral evolution of cool white dwarfs that were made possible thanks to these improved models. We discuss in particular the evolution of the hydrogen-rich to helium-rich ratio at low effective temperatures as well as the DQ→ DQpec transition.

We address the question of identifying the long-term (secular) stability regions in the semi-major axis-eccentricity projected phase space of the Sun-Jupiter planar circular restricted three-body problem in the domains i) below the curve of apsis equal to the planet’s orbital radius (ensuring protection from collisions) and ii) above that curve. This last domain contains several Jupiter’s crossing trajectories. We discuss the structure of the numerical stability map in the (a,e) plane in relation to manifold dynamics. We also present a closed-form perturbation theory for particles with non-crossing highly eccentric trajectories exterior to the planet’s trajectory. Starting with a multipole expansion of the barycentric Hamiltonian, our method carries out a sequence of normalizations by Lie series in closed-form and without relegation. We discuss the applicability of the method as a criterion for estimating the boundary of the domain of regular motion.

Jellyfish galaxies are the most striking examples of galaxies undergoing ram pressure stripping – the removal of gas as a result of a hydrodynamic friction in dense environments. As part of the OMEGA (OSIRIS Mapping of Emission-line Galaxies in Abell 901/2) survey, we have identified the largest sample of jellyfish galaxies in a single system to this date, located in the Abell 901/2 multi-cluster system at z ˜ 0.165. We present our results with a detailed description of this sample regarding their very high star formation rates and their unique spatial distribution pattern that can be explained as a result of the merging system triggering ram pressure stripping events. Furthermore, we also show the results of our most recent morphometric studies where we use Morfometryka as a tool to characterise the morphologies and structural evolution of jellyfish galaxies. Our morphometric analysis shows that jellyfish galaxy candidates have peculiar concave regions in their surface brightness profiles. Therefore, these profiles are less concentrated (lower Sérsic indices) than other star forming galaxies that are not experiencing such extreme ram pressure effects.

We present the case of hot semi-detached Algols showing photometric cycles longer than the orbital period. The evidence indicating that this long cycle might be due to a magnetic dynamo operating in the rapidly rotating donor star is examined.

We discuss the time-series behavior of 8 extragalactic 3FGL sources away from the Galactic plane (i.e., |b|⩾10°) whose uncertainty ellipse contains a single X-ray and one radio source. The analysis was done using the standard Fermi ScienceTools, package of version v10r0p5. The results show that sources in the study sample display a slight indication of flux variability in γ-ray on monthly timescale. Furthermore, based on the object location on the variability index versus spectral index diagram, the positions of 4 objects in the sample were found to fall in the region of the already known BL Lac positions.

Despite significant progress over the past decades, all state-of-the-art population synthesis (PS) codes suffer from deficiencies limiting their potential of gaining sharp insights into the star formation history (SFH) and Chemical Enrichment History (CEH) of star-forming galaxies, i.e. the neglect of nebular continuum and, the lack of a mechanism to ensure consistency between the best-fitting SFH and the observed nebular characteristics (ONC; Balmer-lines, Balmer/Paschen jumps). These introduce biases in their recovered physical properties (stellar mass M* and sSFR). FADO is a novel self-consistent PS code employing genetic optimization, publicly available (http://www.spectralsynthesis.org), capable of identifying the SFH & CEH that reproduce the ONC of a galaxy, alleviating degeneracies in the spectral fits. The current version of FADO (v1.b) uses standard BPT emission-line ratios for the classification of low redshift (z) galaxies. Whereas this permits a reliable distinction between star-forming, Composite, Seyfert and LINERs, it is inapplicable to many intermediate-z galaxies. We present an adaptation of FADO (version v1.c) to classify higher z galaxies employing the “Blue Diagram” (e.g., Lamareille 2010) for which the most prominent blue emission-lines (< [OIII]5007Å) are observable while the Hα and [NII] are inaccessible. FADO v1.c was applied to synthetic spectra simulating the evolution of galaxies formed at higher-z with different SFHs. FADO can recover the physical and evolutionary properties of galaxies, such as M* and mean age/metallicity, with an accuracy significantly better than purely-stellar codes. An outline of FADO v1.c and applications to local and intermediate-z galaxies will be presented.

As observational facilities improve, providing new insights into the chemistry occurring in protoplanetary disks, it is important to develop more complete pictures of the processes that shapes the chemical evolution of materials during this stage of planet formation. Here we describe how primitive meteorites in our own Solar System can provide insights into the processes that shaped planetary materials early in their evolution around the Sun. In particular, we show how this leads us to expect protoplanetary disks to be very dynamic objects and what modeling and laboratory studies are needed to provide a more complete picture for the early chemical evolution that occurs for planetary systems.

The derivation of accurate stellar populations of galaxies is a non-trivial task because of the well-known age-metallicity degeneracy. We aim to break this degeneracy by invoking a chemical evolution model (CEM) for isolated disk galaxy, where its metallicity enrichment history (MEH) is modelled to be tightly linked to its star formation history (SFH). Our CEM has been successfully tested on several local group dwarf galaxies whose SFHs and MEHs have been both independently measured from deep colour-magnitude diagrams of individual stars. By introducing the CEM into the stellar population fitting algorithm as a prior, we expect that the SFH of galaxies could be better constrained.

The spectral energy distribution (SED) model should treat the evolution of a galaxy from its birth. Dust in galaxies affects the formation and evolution of galaxies in various ways. For example, dust grains scatter and absorb stellar emitted ultraviolet (UV) photons and re-emit the radiation at infrared (IR) wavelengths. In this work, we construct a galaxy SED model based on our dust evolution model (Asano et al. 2013a,b, 2014) with a rigorous treatment of the chemical evolution. To reduce the computational cost, we adopt mega-grain approximation (MGA; (MGA; Inoue, 2005). MGA regards a high density dusty region as a huge size (10 pc) dust grain for calculating dust scattering. In this approximation, we can solve the radiative transfer easily and provide SEDs and attenuation curves of galaxies. This model can be used to fit any galaxy in the wavelength range of 10 nm-3 mm.

Very Long Baseline Interferometry (VLBI) offers unrivalled resolution in studies of celestial radio sources. The subjects of interest of the current IAU Symposium, the Active Galactic Nuclei (AGN) of all types, constitute the major observing sample of modern VLBI networks. At present, the largest in the world in terms of the number of telescopes and geographical coverage is the European VLBI Network (EVN), which operates under the “open sky” policy via peer-reviewed observing proposals. Recent EVN observations cover a broad range of science themes from high-sensitivity monitoring of structural changes in inner AGN areas to observations of tidal eruptions in AGN cores and investigation of redshift-dependent properties of parsec-scale radio structures of AGN. All the topics above should be considered as potentially rewarding scientific activities of the prospective African VLBI Network (AVN), a natural “scientific ally” of EVN. This contribution briefly describe the status and near-term strategy for the AVN development as a southern extension of the EVN-AVN alliance and as an eventual bridge to the Square Kilometre Array (SKA) with its mid-frequency core in South Africa.

We present results of a multiwavelength study of the isolated dual AGN system Was 49. Observations show that the dominant component in this interacting system, Was 49a, is a spiral galaxy, while Was 49b is hosted in a dwarf galaxy located at 8 kpc from the nucleus of Was 49a, at the edge of its disk. The intriguing fact about this system is the luminosity of their corresponding AGNs. While Was 49a hosts a low luminosity Seyfert 2 with Lbol˜1043 erg s–1, Was 49b has a Seyfert 2 with Lbol ˜ 1045 erg s–1, in the luminosity range of Quasars. Furthermore, estimates of the black hole and host galaxy masses of Was 49b indicate a black hole significantly more massive than one would expect from scaling relations. This result is in contrast with findings that the most luminous merger-triggered AGNs are found in major mergers and that minor mergers predominantly enhance AGN activity in the primary galaxy.

Roughly speaking, young stars are associated to intense chromospheric activity (CA), whereas it decreases with stellar aging. However, some objects that show high kinematical components – in turn, associated to older stars – reveal CA similar to that of young ones; we call these stars chromospherically young and kinematically old (CYKOs). One hypothesis that could explain their occurrence is the merge of a short-period binary, from which the outcome would be a chromospherically active, kinematically evolved star. Considering that they evolved separately, we expect them to be lithium depleted, and therefore we look for CYKO stars by analyzing their lithium content (λ 6707 Å). We present a preliminary list of 48 stars matching this criteria, aiming to either confirm or discard the coalescence of a short-period pair hypothesis.

The Gaia DR2 has dramatically increased the ability to detect faint nearby white dwarfs. The census of the local white dwarf population has recently been extended from 25 pc to 50 pc, effectively increasing the sample by roughly an order of magnitude. Here we examine the completeness of this new sample as a function of variables such as apparent magnitude, distance, proper motion, photometric color index, unresolved components, etc.

We present the developed methods of digitization, image processing, reduction, and scientific data mining with the latest reference catalogs, which allowed us to obtain a good positional and photometric accuracy in B-band of 6,500 asteroids down to 17.5 m from the Ukrainian Virtual Observatory database of astroplates. The archive includes FON-Kyiv, FON-Kitab, FON-Dushanbe sky surveys (1981–1996) and astroplates of the Baldone and Tautenburg observatories. For some of asteroids, observations are either completely absent or not enough over the certain time interval to the moments of their official discoveries (about 300 such objects were found). Positional observations during these time scales are highly useful for a more detailed study of the dynamics and orbital parameters of asteroids as well as the obtained photometric parameters are very complementary with present-day data for studying changes in brightness and light curves.

The communication project “Herschel and the invisible end of the rainbow” features the year 1800 discovery and today’s application of infrared radiation through diverse methods and different media in order to reach a wide audience. The discovery of the sun’s infrared radiation by the Herschels is demonstrated in a creative way through the publication and performance of a theatre play and accompanying audio play. The documentation of the historical discovery, which changed both science and our daily life, is further supplemented by background information e.g. on the role of women in science in the late 18th and early 19th century. By this, the history of the discovery of infrared radiation becomes alive and easily comprehensible. Additionally, we carry out interactive experiments and demonstrations using a capable thermal infrared camera by which a mostly unknown and strange infrared world becomes visible for all generations. Our recent findings with the infrared space telescope Herschel are used to exemplify modern science use. With this colourful, diverse and interactive communication concept, which is easily extendable and adaptable, we already took part in several science festivals, workshops and training events.

The mass-SFR relation of galaxies encodes information of present and historical star formation in the galaxy population. We expect the intrinsic scatter in the relation to increase to low mass where SFR becomes more stochastic. Measurements at z ‰ 4 from the Hubble Frontier fields have hinted at this (Santini et al., 2017), however, with the added uncertainty of lensing magnification we await JWST to provide robust measurements. Even with data-sets provided by JWST, uncertainties on mass and SFR estimates are often large, potentially covariant and dependent on assumptions used. I will present our method of Bayesian hierarchical modelling of the mass-SFR relation that self-consistently propagates uncertainties on mass and SFR estimates to uncertainties on the mass-SFR relation parameters. I will expose the biases imposed by standard SED-modelling practices, and address to what significance we can measure an increase in intrinsic scatter to low masses with JWST.