Algeria is in the process of building a new astronomical observatory in the Aurès region. This Observatory will be dedicated mainly to the observation and study of transient astrophysical phenomena and in particular the follow-up of the optical counterparts of the Gravitational Waves, The observation of Gamma Ray Bursts, Fast Radio Bursts, Supernovae ... these topics will be devoted to the project of the Aurès Observatory, but also to similar projects around the world, and to the instrumentation that will be deployed.
In the context of the new Observatory, the choice of the site is very important from the point of view of light pollution as well as statistics on cloud coverage, meteorological data, and atmospheric turbulence (seeing, … what makes stars dance in the focal plan of the telescope). Numerous studies and experiments (ground based and satellite based) must be carried out to measure all these parameters.
The first detection of gravitational waves by LIGO on September 14, 2015 (GW150914) and the discovery of astrophysical neutrinos by IceCube have opened a new window on the universe opening up the new era of multimessager astronomy. This will allow us to have a new eye on many objects and more specifically on the compact ones (Neutron stars, black holes…). Although often observed first at high energy, these objects emit through the whole electromagnetic spectrum, from radio waves to gamma rays. These objects are panchromatic, and their complete study requires looking at them throughout the whole spectrum. They are also the main candidates for non-photonic emission like cosmic rays, neutrinos and gravitational waves.
Gravitational waves have been predicted as a consequence of the theory of general relativity. A striking confirmation came from the first direct detection of the coalescence of two massive black holes by Advanced LIGO (GW150914). However, as the sensitivity of the detectors increase, the population of detected events is expected to be dominated by neutron star - neutron star or neutron star - black hole mergers. Such events should have an electromagnetic counterpart, and detection of this counterpart by conventional telescopes is the one of main purposes of the Aurès Observatory.
Gamma Ray Bursts
The origin of gamma-ray bursts (GRBs) – some of the most energetic events ever detected – is still a mystery today, 50 years after their discovery. However, in the era of multi-messenger astronomy, we can take a fresh look at their underlying physics. The gamma-ray bursts allow us to study physics in extreme conditions, relativistic physics, quantum gravity, cosmology, the formation of the first star populations, the evolution of the Universe, and so on.
With the Swift instruments BAT and XRT, we are able to obtain the events position with accuracy of 1 or 2 arcmin . The large telescopes can thus observe them and derive their distance by spectroscopy. However, small telescopes such as TAROT, RAPTOR, or ROTSE can make extremely fast observations of the source during the prompt part, or the beginning of the afterglow. The case of GBM on Fermi is more complicated since the resulting error box is up to 100 square degrees. This problem is similar to the case of gravitational waves source localization and is one of the goals of the Aures Observatory as well as the multi-wavelength observations of GRBs.
Science with Gaia
The Gaia catalog with its various releases, is a magnificent database which may change our understanding of some of the astrophysical phenomena. Indeed, with its volume and its homogeneity, the axes of research ranging from astronomy in the solar system to extragalactic astronomy through the stellar evolution will thrive thanks to the reduction of statistical bias. This will undoubtedly require ground observations by the instruments, even the smallest ones, coordinated on a global scale.
Small Objects of the solar system
Small bodies of the Solar System (SBSS) are object of a wide range of sizes that orbit around the Sun. They are comets, meteors and asteroids. During the course of its mission, Gaia will map all sources brighter than visual magnitude ~20. Among these will be thousands of Solar System objects, primarily main belt asteroids circling the Sun between the orbits of Mars and Jupiter. With its ability to detect faint and fast-moving objects, it is expected that Gaia will also detect several thousand Near-Earth Objects (NEOs), which are thought to be comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighbourhood.
The detection and follow-up of SBSS is one of the secondary objectives of the Aurès observatory du to their relevance and importance. Recent observations have dramatically highlighted the relevance of small bodies for the understanding of Solar system’s dynamical evolution. In fact, small bodies bear clear markers of their origin that can help reconstruct the dynamical paths that led to the current Solar system architecture.
The stellar variability informs us about the different processes that can appear during the evolution of a star. This variability may be of a periodic or non-periodic nature. The time scales for variations range from a few minutes to several years. Similarly, amplitudes of variations vary from a few milli-magnitudes for exoplanetary transits or certain pulsations to several magnitudes for cataclysmic variables such as novae.
The study of stellar variability is in full swing due to its interest in the understanding of certain phenomena of stellar evolution. For some variability, the contribution of small instruments is essential.
New Trends in Astrophysics
Since the purpose of the conference is to bring tpgether researchers in astronomy and astrophysics in Algeria, this topic is an opportunity for some other hot subjects to be presented during this conference.