In this report we present an attempt to find a characteristic set of the space weather parameters allowed to identify the dominant physical connections. This study is based on the data of vertical and oblique sounding of the ionosphere in 2015-2016.

The present-day response of a Galactic disc stellar population to a non-axisymmetric perturbation of the potential, in the form of a bar or spiral arms, can be treated, away from the main resonances, through perturbation theory within the action-angle coordinates of the unperturbed axisymmetric system. The first order moments of such a perturbed distribution function (DF) in the presence of spiral arms give rise to non-zero radial and vertical mean stellar velocities, called breathing modes. Such an Eulerian linearized treatment however diverges at resonances. The Lagrangian approach to the impact of non-axisymmetries at resonances avoids this problem. It is based on the construction of new orbital tori in the resonant trapping region, which come complete with a new system of angle-action variables. These new tori can be populated by phase-averaging the unperturbed DF over the new tori. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data with an action-based DF.

Using data from the Radial Velocity Experiment (RAVE) and the Tycho- Gaia astrometric solution catalogue (TGAS), we study the vertical velocity (Vz) patterns in the Milky Way disc. We search in particular for variation in velocity with distance above and below the disc midplane. In contrast to previous suggestions of a breathing mode seen in RAVE data, our results support a combination of bending and breathing modes, likely generated by a combination of external or internal and external mechanisms.

From 1977 to 1999, thousands of accurate radial velocities in both hemispheres were made on a large variety of programmes with the two CORAVEL scanners. The data base of ~350000 individual observations will now be made available to complement the Gaia data.

The Milky Way is a barred galaxy whose central bulge has a box/peanut shape and consists of multiple stellar populations with different orbit distributions. This review describes dynamical and chemo-dynamical equilibrium models for the Bulge, Bar, and inner Disk based on recent survey data. Some of the highlighted results include (i) stellar mass determinations for the different Galactic components, (ii) the need for a core in the dark matter distribution, (iii) a revised pattern speed putting corotation at ~6 kpc, (iv) the strongly barred distribution of the metal-rich stars, and (v) the radially varying dynamics of the metal-poor stars which is that of a thick disk-bar outside ~1 kpc, but changes into an inner centrally concentrated component with several possible origins. On-going and future surveys will refine this picture, making the Milky Way a unique case for studying how similar galaxies form and evolve.

The interplanetary magnetic field (IMF) controls magnetospheric currents which cause variations of the ground-based magnetic field. Regular magnetic observations made in the 19th century allow us to infer daily IMF polarities back to 1844. The results coincide with satellite data in about 79% days. Moreover, for the most part of the 19th and 20th centuries, proxies obtained from various geomagnetic data (Helsinki, Saint-Petersburg, Potsdam, and Ekaterinburg) show the same patterns. This suggests that the reliability of the proxies is sufficient to study the IMF in the past. The large-scale organization of the IMF polarities, the so-called sector structure, reveals semi-centennial north-south displacements of the heliospheric current sheet (HCS).

Preliminary results of distinguishing solar filaments on daily observation data at the Hα spectral line of the Kodaikanal Solar Observatory (1912-2002) are presented.

To distinguish the boundaries of solar filaments, methods have been developed, based on automatic procedures for distinguishing low-contrast objects on the solar disk as well as on editing the boundaries of selected structures in semi-automatic mode. An analysis of solar filaments’ characteristics has been performed. We are considered variation of the average tilt-angle and the radius of curvature of the filaments in 15-23 cycles of activity.

The prediction of solar flares, eruptions, and high energy particle storms is of great societal importance. The data mining approach to forecasting has been shown to be very promising. Benchmark datasets are a key element in the further development of data-driven forecasting. With one or more benchmark data sets established, judicious use of both the data themselves and the selection of prediction algorithms is key to developing a high quality and robust method for the prediction of geo-effective solar activity. We review here briefly the process of generating benchmark datasets and developing prediction algorithms.

Much progress has been achieved in the age-dating of old stellar systems, and even of individual stars in the field, in the more than sixty years since the evolution of low-mass stars was first correctly described. In this paper, I provide an overview of some of the main methods that have been used in this context, and discuss some of the issues that still affect the determination of accurate ages for the oldest stars.

Using RAVE DR5, we explore the age, kinematic, and chemical correlations of a sample of  30,000 FGK stars. We separate a sample of turnoff stars into two age groups: young and old. For each of the two age groups, we calculate kinematic trends as a function of Galactocentric radius (R), for different metallicity ([Fe/H]) bins. For both young and old stars, we measure a negative gradient in ∂〈VR〉/∂R. In addition, for young stars we find a correlation between the magnitude of the slope and metallicity, with the most metal-rich bins having the steepest gradient and the most metal-poor bins having a flatter trend.

The apostle cosmological hydrodynamical simulation suite is a collection of twelve regions ~5 Mpc in diameter, selected to resemble the Local Group of galaxies in terms of kinematics and environment, and re-simulated at high resolution (minimum gas particle mass of 104 M⊙) using the galaxy formation model and calibration developed for the eagle project. I select a sample of dwarf galaxies (60 < Vmax/km s−1 < 120) from these simulations and construct synthetic spatially- and spectrally-resolved observations of their 21-cm emission. Using the 3Dbarolo tilted-ring modelling tool, I extract rotation curves from the synthetic data cubes. In many cases, non-circular motions present in the gas disc hinder the recovery of a rotation curve which accurately traces the underlying mass distribution; a large central deficit of dark matter, relative to the predictions of cold dark matter N-body simulations, may then be erroneously inferred.

We use numerical simulations from the Community Coordinated Modeling Center to provide, for the first time, a coherent temporal description of the magnetic reconnection process of two dayside Electron Diffusion Regions (EDRs) identified in Magnetospheric Multiscale Mission data. The model places the MMS spacecraft near the separator line in these most intense and long-lived events. A listing of 31 dayside EDRs identified by the authors is provided to encourage collaboration in analysis of these unique encounters.

In order to investigate the origin of multiple stellar populations in the halo and bulge of the Milky Way, we have constructed chemical evolution models for the low-mass proto-Galactic subsystems such as globular clusters (GCs). Unlike previous studies, we assume that supernova blast waves undergo blowout without expelling the pre-enriched gas, while relatively slow winds of massive stars (WMS), together with the winds and ejecta from low and intermediate mass asymptotic-giant-branch stars (AGBs), are all locally retained in these less massive systems. We find that the observed Na-O anti-correlations in metal-poor GCs can be reproduced, when multiple episodes of starbursts are allowed to continue in these subsystems. A specific form of star formation history (SFH) with decreasing time intervals between the stellar generations, however, is required to obtain this result, which is in good agreement with the parameters obtained from our stellar evolution models for the horizontal-branch. The “mass budget problem” is also much alleviated by our models without ad-hoc assumptions on star formation efficiency (SFE) and initial mass function (IMF). We also applied these models to investigate the origin of super-helium-rich red clump stars in the metal-rich bulge as recently suggested by Lee et al. (2015). We find that chemical enrichments by the WMS can naturally reproduce the required helium enhancement (ΔY/ΔZ = 6) for the second generation stars. Disruption of proto-GCs in a hierarchical merging paradigm would have provided helium enhanced stars to the bulge field.

The Milky Way (MW) is interacting with its satellite galaxies and the tidal remnants of satellite galaxies have been observed especially in the MW halo. Understanding the spatial and velocity distributions of stars stripped from satellite galaxies will be of particular importance when interpreting the data from upcoming observations, such as Gaia, Subaru-HSC and PFS. We study tidal stripping events of satellite galaxies with various internal structures using high resolution N-body simulations. The dynamics of satellite galaxies is dominated by dark matter halos, but their density structure is still uncertain. The simulations reveal satellite galaxies with more tightly bound dark matter halos are more robust against the tidal force of the MW and have longer lifetimes than loosely bound ones (Ogiya et al., in prep.). Density scratches on the MW caused by the gravitational force of satellite galaxies and the observability are also discussed (Ogiya & Burkert 2016).

It is well known that the energy for solar eruptions comes from magnetic fields in solar active regions. Magnetic energy storage and dissipation are regarded as important physical processes in the solar corona. With incomplete theoretical modeling for eruptions in the solar atmosphere, activity forecasting is mainly supported with statistical models. Solar observations with high temporal and spatial resolution continuously from space well describe the evolution of activities in the solar atmosphere, and combined with three dimensional reconstruction of solar magnetic fields, makes numerical short-term (within hours to days) solar activity forecasting possible. In the current report, we propose the erupting frequency and main attack direction of solar eruptions as new forecasts and present the prospects for numerical short-term solar activity forecasting based on the magnetic topological framework in solar active regions.

Stars observed in the field of an open cluster are ideal for a controlled test of chemical tagging. Using chemical tagging, one should identify the cluster members, i.e., those stars of similar chemical composition, if their composition is indeed different from that of all the non-member stars of the field. Moreover, the abundance-based membership can be checked against membership based on radial velocities and proper motions. Here, I report preliminary results of such an experiment using data from the Gaia-ESO Survey. Although the three membership criteria usually agree, a few interesting examples of discrepant membership classification have been found. In addition, the mean composition of each open cluster was compared to a sample of 1 600 Gaia-ESO field stars. Some cases of field stars with abundances matching those of the open clusters were identified. This experiment suggests that open clusters do not necessarily have unique abundance patterns that set them apart from all other clusters.

In the recent years it has been generally accepted that seismic parameters add an important observational constraint for the study of stellar populations and galaxy evolution. Padova-Trieste (PARSEC) evolutionary tracks are widely used to characterise stellar objects and stellar populations. Stellar models at the base of these studies suffer from uncertainties and, more important, degeneracy among different input parameters: stellar mass, chemical composition, central chemical mixing, age, etc. Adding seismic properties to the classic parameters for stars at different evolutionary states, from the H main-sequence to the asymptotic giant branch, is a powerful tool to calibrate physical processes in stellar models, and hence to improve our interpretation of Galactic and extra-Galactic observations.

In studying Galactic open clusters based on LAMOST DR3, we deliberately selected several nearby cluster, which have relatively large projection area and reliable proper motion measurements. For each cluster, we firstly determine the typical proper motion distribution profiles in the cluster-core and the outskirt region, respectively, and perform field-star decontamination on the cluster area. We then calculate kinematic membership probability for each star in the cluster area and cross-match the highly probable members with LAMOST DR3 spectral catalog. Based on enhanced signal of cluster-member radial velocity distribution emerging from the whole field, we have also obtained reliable radial velocity membership probability for each star. Finally, we perform isochrones fitting with MCMC technique to study basic properties of these cluster, including age, metallicity, and distance modulus.

We describe the DR14 APOGEE-TGAS catalogue, a new SDSS value-added catalogue that provides precise astrophysical parameters, chemical abundances, astro-spectro- photometric distances and extinctions, as well as orbital parameters for ~30, 000 APOGEE-TGAS stars, among them ~5, 000 high-quality giant stars within 1 kpc.