PLATO is ESA’s M3 mission for launch in 2026. It will search for extrasolar planets by means of ultra-high-precision transit photometry. This requires a well-selected and well-defined stellar input sample for optimized planet harvesting. Two long-duration PLATO fields form the core of the mission. The one field in the southern hemisphere will be observed with BMK10k well in advance of the mission for support of its target input catalog. The BMK10k survey will provide well-sampled light curves of all resolvable targets in the 2250 square degree southern field. The task is to determine false positives (mostly close-by eclipsing binaries) and extract a variability flag for all accessible stars on the basis of their long-term brightness rms. It will enable the pre-determination of precise photometric periods, in particular stellar rotation periods, and the expected degree of (spot) activity. Besides, the survey will identify and characterize the target contamination down to the BMK10k resolution limit of 2.5"/pix for every PLATO pixel and photometry window (PLATO’s pixel size will be 15", similar to TESS‘s 21"; PLATO’s photometry window is 90" squared). The survey also extends the northern STELLA Open Cluster Survey (SOCS) to the southern hemisphere with initial focus on Ptolemy’s cluster.

During their more than six years in space, the five BRITE-Constellation nano-satellites have completed observations of more than 550 individual targets brighter than about 6th magnitude. The data have allowed us to study a variety of variability phenomena covering a wide range across the HR-diagram including different types of pulsations, wind phenomena, rapidly rotating stars (e.g. Be), binary and multiple systems, and stars with planets. Some of the prime science results therefore comprise the discovery of massive heartbeat systems, the apparent interaction of phenomena on very different time scales in Be stars, the proof of a photospheric connection for the wind variations in very massive stars, g-modes and g-mode period spacings in beta Cephei, SPB and gamma Doradus stars or the presence of only two pulsation modes in a magnetic delta Scuti star. I will give an overview of the latest scientific results obtained from BRITE-Constellation data.

The Transiting Exoplanet Survey Satellite (TESS; Ricker et al., 2015, JATIS 1, 014003) was launched on April 18, 2018, and started its scientific observations on June 25, 2018. It is gathering ultra-precise photometric observations for celestial objects with I__C $\approx$ 4 - 13 and an ecliptic latitude above 6 degrees. Preselected targets are observed with a cadence of 2 minutes while full-frame images are obtained every 30 minutes. In two years time, the largest part of the sky will be scanned with 26 sectors of 24 degrees x 96 degrees for a duration of 27 days each. During the first year of the mission, the satellite is pointing to the ecliptic southern hemisphere before moving on to the north in the second year of observations. Given that the sectors overlap near the ecliptic poles, the total time span of the observations of a star can last up to 351 days, depending on its ecliptic latitude. The main aim of the mission is to detect planetary transits in the light curves of nearby stars but the TESS data will be a goldmine for variable stars of all types and flavors. The observations of the first few sectors have been released by now. During this talk, I will show the importance of TESS for asteroseismology of different types of pulsating stars based on a few examples of first results.

The Transiting Exoplanet Survey Satellite (TESS) has been gathering light curves for thousands of nearby stars. Although its primary goal is to find planets, the 2-minute cadence light curves obtained by TESS for pre-selected stars, with precision better than 1\%, are also ideal to search for variability effects caused by a binary companion, such as reflection and eclipses. The brightness of TESS pre-selected targets also makes them ideal for ground-based follow-up, allowing for thorough characterisation of the observed systems and providing constraints for binary evolution models. In this talk, we will show recent discoveries in the field of compact binary stars made possible by TESS, as well as discuss the desired follow-up observations for these systems.

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Euclid is the next ESA space telescope dedicated to cosmology, to be launched in 2022. It will perform a large survey of galaxies over 15000 sq. deg. of the Extragalactic sky. The design of the survey is mostly performed by the Euclid Consortium, with some help of the Science Operation Centre (ESA), while survey operations are performed by the SOC. In this presentation, we will concentrate on the science operation aspects of the Euclid survey, including daily planning and monitoring of the survey, planned reaction to contingencies and under-performance, re-scheduling and other modifications of the planned survey. We will also present the organizational aspect of this activity, which involves many actors of the Ground Segment.

The Hamburg Quasar Survey carried out 1985 - 1997 was using the Calar Alto Schmidt telescope equipped with an objective prism. The survey covered the Northern sky at galactic latitudes b > 20 deg, and declination delta > 0 deg). The spectroscopic Schmidt contain usable spectra with a seeing limited resolution of 45 Angstroem at Hgamma in the magnitude range 14 < B < 19. The HQS archive contains 1288 plates for 567 fields. These plates were scanned in full mapping mode by the Hamburg PDS microdensitometer and the digitized database was used for a variety of astronomical applications, in addition to the search for (mostly bright) quasars. The analysis of HQS prism spectra of quasars discovered by more recent sky surveys may unearth 'changing look' quasars, in which dramatic changes in the accretion process may have occurred on timescales of tens of years.

The all-sky Calar Alto/ ESO Schmidt objective prism surveys led to discoveries in the fields of

• HeII reionization/HeII Lyman forest
• a dozen bright gravitationally lensed multiple OSOs
• The most metal deficient PopII stars known

A review on the main characteristics of Byurakan spectroscopic surveys: Markarian survey (or the First Byurakan Survey, FBS) and the Second Byurakan Survey (SBS), their comparison with other similar surveys and the importance of Markarian galaxies and other objects discovered on the basis of FBS and SBS in modern astrophysics. Markarian Survey was the first systematic survey for active galaxies and was a new method for search for such objects. Until now, it is the largest objective prism survey of the sky (17,056 sq. deg). It was carried out in 1965-1980 by B. E. Markarian et al. and resulted in discovery of 1515 UV-excess (Markarian) galaxies. They contain many active galaxies (both AGN and Starbursts, SB), as well as powerful gamma-ray, X-ray, IR and radio sources (Mrk 180, 231, 421, 501, etc.), BCDGs (Mrk 116) and interacting/merging systems (Mrk 266, 273, etc.). They led to the classification of Seyfert galaxies into Sy1 and Sy2 and the definition of SBs. Markarian galaxies have been published in several catalogs (Mazzarella \& Balzano 1986; Markarian et al. 1989, 1997; Bicay et al. 1995; Petrosian et al. 2007). Markarian survey also served as a basis for search for UVX stellar objects (or blue stellar objects, BSOs, including QSOs and Seyferts), late-type stars and optical identification of IR sources. 1103 BSOs, 1471 late-type stars, and some 1600 IRAS sources have been revealed and identified. At present the survey is digitized and DFBS database is created, which also serves as a basis for the Armenian Virtual Observatory (ArVO). SBS was carried out in 1978-1991 by B. E. Markarian, J. A. Stepanian et al. and covers smaller area (965 sq. deg.) but goes deeper to $19^m$ and has wider wavelength coverage. Both extended (emission-line and UVX galaxies) and stellar (QSOs and blue stars) objects have been revealed, more than 3600 objects in total. Byurakan surveys have played an important role in modern (especially) extragalactic astronomy and the objects revealed from them are being intensely investigated worldwide.

LAMOST survey is a Chinese-operated spectroscopic survey using a 4-meter reflective Schimdt telescope. Since 2011, it has collected about 10 million low-resolution spectra, most of which are stellar spectra. The LAMOST survey continuously covering a large fraction of northen sky allows for broad studies about the Milky Way, especially for the Galactic outer disk. I will briefly highlight the achievment of the LAMOST survey in stellar physics and the Milky Way science. Then I will introduce the LAMOST II project for medium-resolution spectroscopic survey started since October 2018. Unlike LAMOST I, the new medium-resolution survey will not only about the Milky Way but more focus on stellar physics. It also conducts a time-domain spectroscopic survey for about 200 thousands stars in the next 5 years. We expect that the LAMOST II survey will have new breakthrough in stellar physics, especially about binaries, pulsators, young stars, and some pecular stars, by providing time-domain spectroscopic data and synergy with Gaia data in the near future.

Results of the RAVE Survey

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