PhD study at the Astronomical Institute

The Astronomical Institute organizes PhD study in astronomy and astrophysics.

Application deadline: May 15th 2018
Address: Astronomicky ustav SAV
059 60 Tatranska Lomnica
Interviews: end of June 2018
PhD study (start): September 1st 2018
  1. Extrasolar planets and brown dwarfs
    Supervisor: Dr. Jan Budaj (budaj@ta3.sk)
    Workplace/Affiliation: Astronomical Institute, Slovak Academy of Sciences, Tatranska Lomnica, Slovak Republic
    Extrasolar planets and brown dwarfs are exotic substellar objects which were discovered only recently. Their atmospheres are very cold but they may be strongly irradiated. They form clouds from which iron, glass, or salt can rain. A complex study of these objects may include astronomy, physics, meteorology, astronomy, geophysics, chemistry and even biology. This field of research is evolving quickly opening new possibilities, surprises and challenges. That is why also the focus of the thesis may shift according the current situation, availability of data, as well as interests and activity of the student. Mainly the following areas will be targeted:
    -disintegrating exoplanets or "exo"bodies on close orbits around their parent stars,
    -eclipsing stellar systems with dark dusty disks - a craddle for planets (photometry and modelling of spectra and lightcurves),
    -reflection effect and albedo in interacting binaries and exoplanets (photometry and modelling),
    -transit timing variations and search for possible new exoplanets (photometry).
    knowledge of English language, basics of Astronomy and Astrophysics.
    Welcomed experience:
    programming (Fortran), Linux operating system, and astronomical observations.
    Research field:
  2. Instability of magnetised jets in the solar atmosphere.
    Supervisor: Dr. Peter Gömöry (gomory@ta3.sk)
    Affiliation: Astronomical Institute of the Slovak Academy of Sciences, The Department of Solar Physics
    Consultant: Dr. Teimuraz Zaqarashvili (teimuraz.zaqarashvili@oeaw.ac.at)
    Affiliation: Space Research Institute, Graz, Austria
        Focus of the research: Solar magnetized jets play significant role in shaping of plasma state in the solar atmosphere. Observations show various kinds of motions in the chromosphere/corona with different temperatures, speeds, and other plasma parameters. Most enigmatic features are spicules, which appear as cold dense chromospheric jets rising up into the corona. Some of spicules (type II spicules) show very short life time (from tens of seconds to few minutes), which is probably connected to their fast heating to coronal temperature. The heating can be connected with flow instabilities, but the exact physical mechanism is unknown. The goal of the thesis is to study the Kelvin-Helmholtz (KH) instability in twisted magnetised jets of partially ionised chromospheric plasma. KH vortices can be damped due to collisions of ions with neutral hydrogen atoms and hence might lead to the observed fast heating of type II spicules.
        Objectives: Single and two-fluid magnetohydrodynamic equations of partially ionised plasmas will be used to study the KH instability in twisted jets. Analytically obtained growth rates and thresholds of KH instability will be supplemented and tested by fully nonlinear numerical simulations. The obtained results will be compared with high resolution observations obtained by SST and IRIS.
    good background in physics, basic knowledge in programing (IDL, Fortran), basic English
    Research field:
    Physics of the solar atmosphere.
  3. Interstellar particles in the Solar system's interplanetary medium
    Adviser: RNDr. Mária Hajduková Jr., PhD. (Maria.Hajdukova@savba.sk)
    Affiliation: Astronomical Institute of the Slovak Academy of Sciences, The Departement of Interplanetary Matter, Bratislava
        Focus of the research: The interaction of our Solar system with the interstellar medium, due to the motion of the Sun relative to the local interstellar cloud, should lead to the presence of interstellar particles, or, at least, interstellar dust grains. Viewed from within the Solar system, a flow of interstellar matter should be observed. Since identifying particles of interstellar origin is a challenge, the true abundance of interstellar particles in the Solar system has not yet been unambiguously determined.
        Objectives: The aim of this work is to map the influx of the interstellar particles and follow their trajectories through the Solar system. These are influenced by their interaction with the interplanetary medium and controlled by a number of size-dependent forces. The emphasis of this work lies on large particles approaching the Earth's orbit on hyperbolic orbits with respect to the Sun, which can be observed as meteors.
    Computer simulations of interstellar particles' trajectories will be compared with observational data from the avaliable meteor databases. The substantial question is the ratio of the interstellar particles to those belonging to the interplanetary medium, which we should register in a particular region. This depends on the distance from both the Sun and the ecliptic. Therefore, the results of Earth-based and space-born observations will be synthesized to achieve a broader view.
    programming, the English language
    Research heading:
    The dynamical evolution of the small bodies of the Solar system

For further information, please contact supervisors via email...

In Tatranska Lomnica, February 20th, 2018

Mgr. Martin Vaňko, PhD.
Director of the AISAS

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