We are monitoring nearby long period variable stars (LPVs) in the near infrared K band to establish their precise Period-Luminosity relation. However, they are very bright in the near-infrared and it is difficult to observe them because they are easily saturated on the modern near-infrared camera. We developed a special ND filter, named Local Attenuation Filter (LAF), to observe very bright stars. Using LAF, we can observe not only the very bright targets without saturation but also reference stars in the same image. We can perform the accurate relative photometry for the bright stars. We present this new method to observe bright stars as well as the status of our monitoring of nearby LPVs.

Comparison of the Gaia DR1 auxiliary quasar solution to recent ground based VLBI solutions for ICRF2 sources.

Proper motions (PMs) are required to calculate accurate orbits of globular clusters (GCs) in the Milky Way (MW) halo. We present our HST program to create a PM database for 20 GCs at distances of R GC = 10–100 kpc. Targets are discussed along with PM measurement methods. We also describe how our PM results can be used for Gaia as an external check, and discuss the synergy between HST and Gaia as astrometric instruments in the coming years.

We took advantage of the Gaia DR1 to combine TGAS parallaxes with Tycho-2 and APASS photometry to calculate the star formation history (SFH) of the solar neighbourhood within 250 pc using the colour-magnitude diagram fitting technique. We present the determination of the completeness within this volume, and compare the resulting SFH with that calculated from the Hipparcos catalogue within 80 pc of the Sun. We also show how this technique will be applied out to ~5 kpc thanks to the next Gaia data releases, which will allow us to quantify the SFH of the thin disc, thick disc and halo in situ, rather than extrapolating based on the stars from these components that are today in the solar neighbourhood.

In connection with long on-orbit European space satellite Gaia and the opportunity that now provides ESA, to use the results of observations of the space telescope, we would like to present some results of our long-term observations of the major planets satellites at Pulkovo Observatory. We hope to translate into reality these opportunities, namely the use of new observations and new ephemeris and a practical possibility of a new reduction for modern and old observations. The essential facilities can appear in the space, we give the shortest presentation of space project Orbital Stellar Stereoscopic Observatory.

Binarity is now a well-established quality affecting a large fraction of stars, and recent studies have shown that the fraction of binaries is a function of the spectral type of the primary star, with most massive stars being member of a close binary system. By cross-matching TGAS with S B9 , we went one step further and derived the mass ratio distribution of binary systems as a function of the spectral type of the primary star. This, combined with the binary fraction, provides very strong constraints on star formation and critical input for stellar population models.

In this work we present chemical abundances of heavy elements (Z>28) for a homogeneous sample of 1059 stars from HARPS planet search program. We also derive ages using parallaxes from Hipparcos and Gaia DR1 to compare the results. We study the [X/Fe] ratios for different populations and compare them with models of Galactic chemical evolution. We find that thick disk stars are chemically disjunt for Zn adn Eu. Moreover, the high-alpha metal-rich population presents an interesting behaviour, with clear overabundances of Cu and Zn and lower abundances of Y and Ba with respect to thin disk stars. Several abundance ratios present a significant correlation with age for chemically separated thin disk stars (regardless of their metallicity) but thick disk stars do not present that behaviour. Moreover, at supersolar metallicities the trends with age tend to be weaker for several elements.

We report on recent advancement in the theory of light propagation in the Solar System aiming at sub-micro-arcsecond level of accuracy:

1. (1) A solution for the light ray in 1.5PN approximation has been obtained in the field of N arbitrarily moving bodies of arbitrary shape, inner structure, oscillations, and rotational motion.

2. (2) A solution for the light ray in 2PN approximation has been obtained in the field of one arbitrarily moving pointlike body.

ESA's Gaia space astrometry mission is performing an all-sky survey of stellar objects. At the beginning of the nominal mission in July 2014, an operation scheme was adopted that enabled Gaia to routinely acquire observations of all stars brighter than the original limit of G~6, i.e. the naked-eye stars. We present the current status and extent of those observations.

The Lijiang 2.4m telescope of Yunnan Observatories is located at longitude E100°01′51″, latitude N26°42′32″ and height 3250m above sea level (IAU code O44). Because of low latitude of the site, long-focus system and planetary tracking mode of telescope, high accuracy positioning and spectral classification of the near Earth objects (NEAs) especially in the Southern Hemisphere can be studied with the Lijiang 2.4m telescope. As a set of observational campaigns organized by the GAIA-FUN-SSO, astrometry of several near Earth asteroids including (367943) Duende and (99942) Apophis were made with Lijiang 2.4m telescope during 2013. From December 12, 2015, spectra of three near earth asteroids were also observed with the YFOSC terminal attached to the Lijiang 2.4m telescope. This paper will give the detailed introduction of Lijiaing 2.4m telescope and observational results of near Earth asteroids obtained with it.

Gaia is an ESA cornerstone mission conducting a full sky survey over its 5 year operational period. Gaia performs astrometric, photometric and spectroscopic measurements. The data processing is entrusted to scientists and engineers who have formed the Gaia Data Processing and Analysis Consortium (DPAC). The photometric science alerts started in 2014. The first intermediate data release (Gaia DR1) took place 14 September 2016 and it has been extensively used by the community. Gaia DR2 is scheduled for April 2018. Gaia is expected to be able to continue observations roughly for another 5 years after the nominal phase. The procedure to grant funding for the extension period has been initiated. In case funding is granted, the total operational time of Gaia may be 10 years.

The star forming regions NGC6334 and NGC6357 are amid the most active star-forming complexes of our Galaxy where massive star formation is occuring. Both complexes gather several HII regions but they exhibit different aspects: NGC6334 is characterised by a dense molecular ridge where recent massive star formation is obvious while NGC6357 is dominated by the action of the stellar cluster Pismis 24 which have shaped a large cavity. To understand and compare the formation of massive stars in these two regions requires to precise the distance and characterise the proper motions of the O to B3 stellar population in these regions.

We examined the O-C diagrams of eclipsing binary systems and selected these exhibiting cyclic shape, either sinusoidal or quasi sinusoidal. Assuming these variations being due to the Light Time Travel effect (LTE), we estimated the parameters of companions with the Monte Carlo method. As a result, we identified nearly two dozen of eclipsing systems that might have companions with a minimum mass larger than that of a neutron star. Their masses fall into the range between 1.7 and 34 solar masses. This sample of triples with high mass companions can be confirmed with the help of observations gathered by Gaia: parallaxes and astrometric measurements.

It is a great pleasure for me to report about your colleague and my friend François Mignard. I know him since now 43 years and shared with him some scientific adventures. If, because of my age, I had to leave the Gaia project, I have followed the tremendous work done since by François Mignard and noticed that, despite his masterly played role as the conductor of the Gaia orchestra, he kept an important scientific activity. Actually, Gaia is far from being all his scientific achievements. And this is what I shall try to convince you.

We investigate the kinematics of stars in the Solar neighbourhood by combining radial velocities from the latest data release of the RAVE survey with the Tycho-Gaia Astrometric Solution presented in Gaia Data Release 1. We use moments of the velocity distribution to characterise the kinematics over a radial distance range of 6-10 kpc and up to 1 kpc away from the plane. Our ultimate goal is to use these to put new constraints on the (local) distribution of mass using the Jeans Equations.

It is expected that most massive stars have companions and thus that some core-collapse supernovae should have a runaway companion. The precise astrometry and photometry provided by Gaia allows for the systematic discovery of these runaway companions. We combine a prior on the properties of runaway stars from binary evolution with data from TGAS and APASS to search for runaway stars within ten nearby supernova remnants. We strongly confirm the existing candidate HD 37424 in S147, propose the Be star BD+50 3188 to be associated with HB 21, and suggest tentative candidates for the Cygnus and Monoceros Loops.

Binary and multiple stars have long provided an effective method of testing stellar formation and evolution theories. In particular, wide binary systems with separations > 20,000 au are particularly challenging as their physical separations are beyond the typical size of a collapsing cloud core (5,000 - 10,000 au). We present here a preliminary work in which we make use of the TGAS catalogue and Virtual Observatory tools and services (Aladin, TOPCAT, STILTS, VOSA, VizieR) to identify binary and multiple star candidate systems. The catalogue will be available from the Spanish VO portal (http://svo.cab.inta-csic.es) in the coming months.

Fourier Transform spectroscopy is able to provide high accuracy atomic parameters needed by many ongoing galactic surveys. Our laboratory has carried out a study of the neutral iron spectrum over the last years to measure oscillator strengths much needed for the calculation of chemical abundances. The main aim of this contribution is to encourage further dialogue with astronomers regarding their current necessities of spectroscopic data, as this would help spectroscopists to prioritise present-day needs within the field.

Understanding how young stars and their circumstellar disks form and evolve is key to explain how planets form. The evolution of the star and the disk is regulated by different processes, both internal to the system or related to their environment. The former include accretion of material onto the central star, wind emission, and photoevaporation of the disk due to high-energy radiation from the central star. These are best studied spectroscopically, and the distance to the star is a key parameter in all these studies. Here we present new estimates of the distance to a complex of nearby star-forming clouds obtained combining TGAS distances with measurement of extinction on the line of sight. Furthermore, we show how we plan to study the effects of the environment on the evolution of disks with Gaia, using a kinematic modelling code we have developed to model young star-forming regions.