Multi-wave astronomy provides a means for researchers to see and ‘hear’ the sky. But that is only part of their perception of the cosmos. The hot handshake of the Universe in the form of a meteor substance burning in the Earth’s atmosphere, sometimes with the precipitation of meteorites threatening the environment, occurs every second. A major present challenge for meteor research is organizing observations and processing existing and new data in order to obtain information in the time domain of meteor astronomy for solving special problems. This poster discusses the concept of the meteor sky, and some approaches for constructing models of it. The database of meteors of Kharkiv National University of Radio Electronics was used.

Measurements of current rates of core-collapse supernovæ (CCSNe) suffer from significant uncertainties, probably due to the large fraction of CCSNe that explode in crowded regions which have bright background emission and significant dust extinction. Conventional optical (seeing-limited) SN surveys generally fail to detect them, but including them is crucial to the accurate determination of CCSN rates. Project SUNBIRD aims to tighten the present constraints on the fraction of CCSNe that are missed by conventional SN surveys. We are monitoring more than 25 dusty luminous infrared galaxies that are actively star-forming, for evidence of dust-obscured CCSNe, in an effort to characterise the population of CCSNes exploding in those nuclear regions of dusty LIRGs. We observe in the near-infrared, which is less affected by dust extinction compared to the optical; we are using Gemini South and Keck, and we make use of state-of-the-art laser guide-star adaptive optics instruments to achieve a spatial resolution <0’.1, which is sufficient to resolve close to the galactic nucleus.

During the project’s first year we discovered three CCSNe and one candidate one, with nuclear offsets as small as 200 pc, as cited in the poster. Aggregating the new discoveries with the CCSNe found in previous programmes employing AO, we compared the distribution of nuclear offsets of AO CCSN discoveries with all other documented CCSNe discovered in LIRGs. The poster showed that our method is singularly effective at uncovering CCSNe in the nuclear regions of LIRGs, and that while optical surveys dominate SNe discoveries far from a galaxy’s centre, near infra-red AO observations are needed to probe the regions within 1 kpc of the nucleus.

This poster reported our spectroscopy of the neutron-star X-ray binary 4U 1728-34, observed with Suzaku in 2010 October. It is classified as an atoll source. Its continuous X-ray spectrum can be fitted by a combination of a multicolour accretion-disk model for the soft energy, plus a power-law model for the hard energy. A broad emission line at 6–7 keV can be fitted well using a simple Gaussian component with an equivalent width of ∼322 eV. However, for this object the presence of that feature is disputed, even though our results from Suzaku do suggest the presence of a broad Fe emission line that is consistent with results from XMM-Newton. Nevertheless, the parameters of the line (the line centroid and the equivalent width) are a little different, but that could be due to a difference in modelling the continuum.

There is a strong correlation between coronal mass ejection transients and chromospheric H-α activity. Solar physicists hope to ascertain what causes coronal disturbances, and in our current investigation we are trying to address that problem by assessing the likelihood that a coronal disturbance is associated with other manifestations of the same abrupt, perturbing event such as a flare. The correlation, if any, between filament and flare can be derived by a method of image processing. Our next approach is to give the results of statistical research by studying a century of chromospheric Hα observations. This poster describes the concept and preliminary experiences of deriving the characteristics of a filament and a flare.

HR 6902 was the first target of a systematic study by Griffin (1986, JApA, 7, 195) of binaries showing composite spectra. It is also a well-studied member of the ζ Aur class. ζ Aur systems are long-period eclipsing binaries that are comprised of an evolved giant primary and a hot dwarf companion. Although those component stars have very different effective temperatures they have similar luminosities in the blue and near-UV regions, and hence display a composite spectrum at those wavelengths. In principle the ζ Aur systems are excellent tests of evolutionary and structural stellar models. In recent years the somewhat fragmentary eclipse photometry of HR 6902 has been out-classed by the high-precision continuous monitoring by the space mission CoRoT. HR 6902 was selected as a primary target of its seismology field, because the possible detection of solar-like pulsations in a giant component of a double-lined eclipsing binary could help to calibrate the scaling relation of giant pulsators. Our poster reported the results of a new analysis based on the CoRoT observations and follow-up spectroscopy with HARPS at the ESO 3.6-m telescope at La Silla.

The unprecedented accuracy of the CoRoT photometry enabled us to:

• improve drastically the accuracy of the binary orbit and stellar parameters (by a factor ~10 for the radii)

• extend the test of validity/calibration of the scaling relations to high stellar mass and radius, and put constraints on the evolutionary state (particularly since this binary is certainly free from tidal effects).

In the last decade great strides have been made in understanding the role of binary stars in the evolution and shaping of planetary nebulæ (PNe). Observational efforts have mainly focused on finding close binaries with orbital periods of 1 day or less. Those close binary systems make up around 1 in 5 PNe, and constitute the youngest accessible window into the aftermath of the critical and unobserved common-envelope (CE) phase of binary-star evolution. The poster focused on our recent work with the High Resolution Spectrograph (HRS) on the Southern African Large Telescope (SALT) to search for long-period binaries in PNe. Considerably less is known about such long-period binaries with orbital periods of weeks to years, but they may be fundamental to improving CE population synthesis models and for determining the total binary fraction of PNe. The queue-mode operation of SALT and the excellent sensitivity and stability of HRS (which is enclosed in a vacuum tank) are ideally suited to detecting binaries with low radial-velocity amplitudes over the expected timescales of weeks to years. Many exciting new discoveries about binaries have already been made in this newly-accessible southern horizon in time-domain astronomy thanks to the many unique advantages of SALT.

Detailed analyses of observations by the Kepler satellite may reveal unknown facts about objects that were previously regarded as eclipsing binaries. We present results of our analysis of such an object, KIC 3832716. We show that the system actually contains two eclipsing binaries (EB1 and EB2), with orbital periods of 1.14 and 2.17 days, orbiting around their common centre of mass with period of at least 1400 days and with an estimated mass ratio of 0.7 ± 0.3. Analyses of the (O–C) diagrams of both eclipsing pairs show three different types of variation: (i) long-term changes probably due to light-time effects, (ii) spikes caused by the superposition of the eclipses of both binaries, and (iii) semi-regular variations in EB1 with a period of 57 days, presumably caused by the presence of spots on its secondary component.

Despite the expectation of a high supernova rate in luminous infra-red galaxies (LIRGs), a deficit has been discovered in optical surveys that is due to high levels of extinction by dust and to issues of contrast against the bright nuclear background. Searching in the near infra-red enables observations to penetrate that dust, while using adaptive-optics achieves the resolution required to observe supernovæ close to the nuclei of those galaxies. Over the last decade multiple observing programmes using the best AO instrumentation mounted on large telscopes have accumulated a dataset of many LIRGs, and met with much greater success in discovering nuclear supernovæ. However, a significant proportion is still being missed. By using techniques to evaluate our detection efficiency in these data, and simulations of the supernovæ occuring in the galaxies, we can evaluate the nature of these transients.

Stars are the main ingredients of galaxies, and the sites of the creation of most chemical elements in our universe. The knowledge that we gain from studying nearby resolved stellar populations assists directly our ability to measure the properties of distant galaxies. The overall objective of this project is to study galaxy formation and evolution in a complete environment of the dwarf galaxies in the Local Group, by using the same methods for all of them. For that purpose, we used the INT to conduct a monitoring survey of the majority of Local-Group dwarf galaxies in order to identify the most evolved AGB stars that are long-period variables (LPV). LPV stars reach their maximum brightness amplitudes at optical wavelengths, owing to changes in temperature. They trace stellar populations as young as ∼30 Myr up to as old as ∼10 Gyr, and identifying them is one of the best ways of reconstructing star-formation history using a method that we have developed and applied successfully to other Local-Group galaxies. Since the luminosity variations span 100–1000 days, we planned observations over 10 epochs, spaced ∼3 months apart; 9 epochs of data have so far been obtained.

Photographic plate archives contain a wealth of information about the positions and brightness of celestial objects decades ago. Plate digitization is necessary to make this information accessible, but extracting it is a technical challenge. We have developed algorithms to extract photometry with an accuracy of better than ∼0.1 mag. in the range 13 < B < 17 mag from photographic images obtained in 1948–1996 with the 40-cm Sternberg Institute astrograph (30 × 30 cm plate size, 10 × 10 deg field of view) and digitized using a flatbed scanner. The extracted photographic light-curves are used to identify thousands of new high-amplitude variable stars (>0.2 mag). The algorithms are implemented in the free software VaST available at http://scan.sai.msu.ru/vast/

The All-Sky Automated-Survey for SuperNovæ (ASAS-SN) is a fully automated transient search programme that is currently observing the entire night sky every second night to a depth of about 18th magnitude. Since becoming on-line in mid-2014, ASAS-SN has discovered over half of all bright supernovæ, and along the way has also discovered numerous tidal disruption events, cataclysmic variables, stellar flares and even a comet! ASAS-SN currently has two units deployed between Chile and Hawaii, and an additional three units were slated to come on-line by the end of 2017 at observatories in South Africa, Chile and Texas. The poster provided a brief summary of ASAS-SNs accomplishments, and discussed future prospects based on its global expansion.

With so many spectroscopic surveys, both past and upcoming, such as SDSS and LAMOST, the number of accessible stellar spectra is continuously increasing. There is therefore a great need for automated procedures that will derive estimates of stellar parameters. Working with spectra from SDSS and LAMOST, we put forward a hybrid approach of Kernel Principal Component Analysis (KPCA) and Support Vector Machine (SVM) to determine the stellar atmospheric parameters effective temperature, surface gravity and metallicity. For stars with both APOGEE and LAMOST spectra, we adopt the LAMOST spectra and APOGEE parameters, and then use KPCA to reduce dimensionality and SVM to measure parameters. Our method provides reliable and precise results; for example, the standard deviation of effective temperature, surface gravity and metallicity for the test sample come to approximately 47–75 K, 0.11–0.15 dex and 0.06–0.075 dex, respectively. The impact of the signal:noise ratio of the observations upon the accuracy of the results is also investigated.

The narrow-band Δa photometric system measures the flux depression at λ5200 Å by comparing the flux at the band centre to adjacent regions. It has been shown that virtually all peculiar stars with magnetic fields (mCPs) have significant positive Δa values (of up to +100 mmag), whereas Be/Ae/B[e] and metal weak stars (including lambda Bootis types) exhibit significant negative values of Δa. By using this photometric system we are therefore able to detect chemically peculiar (CP), emission types and metal-weak stars in an efficient way. The poster presented the first results of our survey of the Small Magellanic Cloud. In the selected field we found only 0.5 % of bona fide CP stars against 15 % in our Galaxy.

The Space-based, multi-band, astronomical Variable Object Monitor (SVOM) is a collaborative project between China and France dedicated to the detection, localisation and study of about 60 Gamma Ray Bursts per year, and other high-energy transient phenomena. SVOM is planned to be launched in 2021, with a lifetime of 3–5 years. The poster described our construction and testing of a prototype to set up an interface between our data reduction sub-system, the global VOEvent network, and the French science centre.

Time-domain astronomy is a key theme on research roadmaps worldwide, as was amply demonstrated by the energy which the participants (coming from 33 different countries) brought to this Symposium, as they shared their experience and expertise through various time-domain projects and discussed the challenges and strategies for the road ahead. This short summary is simply a personal view of the many key topics that were discussed.