Wide-angle surveys at different wavelengths are already providing triggers for very different kinds of transients. The most interesting science is produced when new sources are followed-up and characterised by using the right instrumentation, telescopes and observing strategies. In the coming years, with new large-scale surveys such as ZTF and LSST, the amount of triggers is expected to scale up massively. Furthermore, new observational windows, such as gravitational waves or neutrinos, are now opening and adding complexity to the picture. The instrumentation and strategies that we have been using over recent years may just not be appropriate for those new situations. In this Workshop we discussed the present and projected future of transient discovery, the instrumentation that will be needed for the follow-up of those targets, and the observing strategies, data analysis and community efforts that will be required to tackle the challenges that lie ahead of us.

Accurate positional measurements of planets and satellites are used to improve our knowledge of their orbits and dynamics, and to infer the accuracy of the planet and satellite ephemerides. With the arrival of the Gaia-DR1 reference star catalog and its complete release afterward, the methods for ground-based astrometry become outdated in terms of their formal accuracy compared to the catalog's which is used. Systematic and zonal errors of the reference stars are eliminated, and the astrometric process now dominates in the error budget.

We present a set of algorithms for computing the apparent directions of planets, satellites and stars on any date to micro-arcsecond precision. The expressions are consistent with the ICRS reference system, and define the transformation between theoretical reference data, and ground-based astrometric observables.

Due to limitations in available instrumentation and observation time, a spectroscopic determination of distance is not feasible for all objects in the sky. Therefore statistical methods that estimate redshifts, based on photometric measurement are of tremendous importance to many astrophysical questions. Determining cosmological parameters and understanding evolutionary processes in the universe are just two examples. When perform astrophysical analyses, it is necessary to treat the uncertainties of the estimates correctly. Over-simplification of results and the usage of wrong tools to evaluate the performance of probabilistic redshift estimates were commonly found in the literature. We present proper tools for evaluating uncertain redshift estimates and discuss the necessity of multimodal redshift distributions.

Studying the internal dynamics of stellar clusters is conducted primarily through N-Body simulations. One of the major inputs into N-Body simulations is the binary star frequency and mass distribution, which is currently constrained by relations derived from field binary stars. However to truly understand how clustered environments evolve, binary data from within star clusters is needed including masses. Detailed information on binaries masses, primary and secondary, in star clusters has been limited to date. The primary technique currently available has been radial velocity surveys that are limited in depth. Using previous two-band photometry-based studies that may cover different mass ranges produce potentially discrepant interpretations of the observed binary population. We introduce a new binary detection method, Binary INformation from Open Clusters Using SEDs (BINOCS) that covers the wide mass range needed to improve cluster N-body simulation inputs and comparisons. Using newly-observed multi-wavelength photometric catalogs (0.3 - 8 microns) of the key open clusters with a range of ages, we can show that the BINOCS method determines accurate binary component masses for unresolved cluster binaries through comparison to available RV-based studies. Using this method, we present results on the dynamical evolution of binaries from 0.4 - 2.5 solar masses within five prototypical clusters, spaning 30 Myr to 3.5 Gyr, and how the binary populations evolve as a function of mass.

We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3 ± 3.8% of galaxies can be separated from stars using MM, with 19.4 ± 7.9% of the stars being misclassified. We demonstrate that, for photographic plate images, the number of galaxies correctly separated from the stars can be increased using our MM diffraction spike tool, which allows 51.0 ± 6.0% of the high-brightness galaxies that are inseparable in current techniques to be correctly classified, with only 1.4 ± 0.5% of the high-brightness stars contaminating the population. We demonstrate that elliptical (E) and late-type spiral (Sc-Sd) galaxies can be classified using MM with an accuracy of 91.4 ± 7.8%. It is a method involving fewer ‘free parameters’ than current techniques, especially automated machine learning algorithms. The limitation of MM galaxy morphology classification based on seeing and distance is also presented. We examine various star/galaxy differentiation and galaxy morphology classification techniques commonly used today, and show that our MM techniques compare very favourably.

The vast quantities of data produced by modern radio telescopes require advanced visualisation tools to explore them. The quantitative nature of astronomy requires more than just representing data visually. This paper discusses research in displaying, and using, a three-dimensional ‘cursor’ in amorphous, noisy data which often resemble wispy tendrils.

The time-domain community wants robust and reliable tools to enable the production of, and subscription to, community-endorsed event notification packets (VOEvent). The Virtual Astronomical Observatory (VAO) Transient Facility (VTF) is being designed to be the premier brokering service for the community, both collecting and disseminating observations about time-critical astronomical transients but also supporting annotations and the application of intelligent machine-learning to those observations. Two types of activity associated with the facility can therefore be distinguished: core infrastructure, and user services. We review the prior art in both areas, and describe the planned capabilities of the VTF. In particular, we focus on scalability and quality-of-service issues required by the next generation of sky surveys such as LSST and SKA.

Virtual Observatory (VO) is a data intensive online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless and uniform access to astronomical information. The concept of VO was introduced in the late 1990s to meet the challenges brought up with data avalanche in astronomy. In the paper, current status of International Virtual Observatory Alliance, technical highlights from world wide VO projects are reviewed, a brief introduction of Chinese Virtual Observatory is given.

We present a powerful new tool to disentangle the 3-D geometry and kinematic structure of gaseous nebulae. The method consists of combining commercially available digital animation software to simulate the 3-D structure and expansion pattern of the nebula with a dedicated, purpose built rendering software and graphical user interface that produce the final images and long slit spectra which are compared to the real data.

The Virtual Observatory (VO) will revolutionise the way we do Astronomy, by allowing easy access to all astronomical data and by making the handling and analysis of datasets at various locations across the globe much simpler and faster. I report here on the need for the VO and its status in Europe, including the first ever VO-based astronomical paper, and then give two specific applications of VO tools to open problems of A-stars research.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html