My project is called "ECLIPSE: Exploring compact stellar remnants and their impact on star clusters evolution" and its primary objective is to study the long-term evolution of stellar systems composed of stars and their compact remnants – white dwarfs (WDs), neutron stars (NSs) and black holes (BHs).
The visible universe is hierarchical – a complex structure organised on a vast range of scales, from aggregates of galaxies to individual stars. But the fundamental building blocks of it all are star clusters (SCs), providing us with essential information on the formation and evolution of stars and on the dynamical development of their host Galaxy. However, because of their distance and size, measuring precise information about their internal structure and composition is challenging. Their stellar components age and evolve on nuclear timescales, Myr to Gyr, and the global dynamical evolution of SCs or the Galaxy is similarly slow. Therefore, it is crucial to study SCs through a multidimensional approach – combining robust theories and their implementations in numerical simulations with state-of-the-art observational data, and eventually also incorporate machine-learning techniques.
Research publications
Pavlík V., Davies M. B., Leitinger E. I., Baumgardt H., Bobrick A., Cabrera-Ziri I., Hilker M., Winter A. J. (2024), Spatial mixing of stellar populations in globular clusters via binary-single star scattering, submitted to Astronomy & Astrophysics, eprint arXiv:2508.03322
Pavlík V., Karas V., Bhat B., Peißker F., Eckart A. (2024), Dynamics of star associations in an SMBH–IMBH system: The case of IRS13 in the Galactic centre, Astronomy & Astrophysics, Volume 692, id. A104, DOI:10.1051/0004-6361/202452050
Pavlík V., Heggie D. C., Varri A. L., Vesperini E. (2024), Dynamics of star clusters with tangentially anisotropic velocity distribution, Astronomy & Astrophysics, Volume 689, id. A313, DOI:10.1051/0004-6361/202450270
Conference proceedings
Pavlík V., Karas V., Bhat B., Peißker F., Eckart A. (2024), Dynamics of IRS13-like clusters in the Galactic centre, Appearance and Dynamics of Accretion onto Black Holes, held 5-9 November, 2024 at Astronomical Institute, Czech Academy of Sciences, Prague, ADS link
Pavlík V., Heggie D. C., Varri A. L., Vesperini E. (2024), Relaxation and evolution towards inverse energy equipartition in star clusters,
In proceedings of "MODEST-24: Exploring Dense Stellar Systems Across Cosmic Time", Nicolaus Copernicus Astronomical Center, Warsaw, Poland, ADS link
Fuksa M., Pavlík V., Karas V., Shore S. N. (2024), Detailed study of the stability of planetary systems captured by a massive stellar remnant, In proceedings of "MODEST-24: Exploring Dense Stellar Systems Across Cosmic Time", Nicolaus Copernicus Astronomical Center, Warsaw, Poland, ADS link
Conference organisation
LOC and Newsletter Editor-in-Chief of IAU Symposium 405, will be held in 2026 at Masaryk University, Brno
SOC and LOC of AI&GW@CZ, will be held in November, 2025 at the Astronomical and the Geophysics Institutes of the Czech Academy of Sciences, Prague
LOC and Proceedings Editor of Appearance and Dynamics of Accretion onto Black Holes, held 5-9 November, 2024 at the Astronomical Institute of the Czech Academy of Sciences, Prague. Proceedings are available on Zenodo.
Dissemination activities
Pavlík V. (2025), Perseus a Andromeda, Aventinum, ISBN:978-80-7442-160-0
Pavlík V. (2024), O zmizelé hvězdě, Aventinum, ISBN:978-80-7442-157-0
I also give lectures at elementary and secondary schools as well as kindergartens on anything related to astronomy. I make the lectures very interactive, so that the specific discussion can develop according to what the children are interested in. See also Outreach and Teaching.
My area of interest is the dynamical evolution of stellar systems. I specialise in numerical modelling and theoretical investigation of star clusters and their constituent stars. This includes the dynamical evolution of binary stars and stellar remnants, the impact of star clusters on the Galaxy, or probing the channels of planetary systems formation. My work is often motivated by observational results or aimed to provide constraints to our interpretation of observations.
Insights into spatial mixing of multiple populations in dynamically-young globular clusters
We showed that binary–single star interactions may explain why some dynamically-young globular clusters have their first and second stellar populations spatially mixed. The preprint of our article will be available soon.
Invited lecture at the General Meeting of the Indiana Astronomical Society
Doomsday dynamical scenarios
We discuss what would happen if the Solar system encountered a fast moving black hole. We also show the possible candidates in the Solar neighbourhood.
53rd DDA Meeting
Effects of radially anisotropic velocity distribution on the dynamics of star clusters
We are exploring various aspects of the dynamics of star clusters characterised by a radially anisotropic velocity distribution. In our first study (Pavlik & Vesperini 2021), we used N-body simulations to show that radially anisotropic systems are characterised by more rapid evolution towards energy equipartition than isotropic ones. In the subsequent extension (Pavlik & Vesperini 2022), we explored the development of mass segregation, the evolution of primordial binaries, and the influence of the Galactic tidal field. I will present an overview of our results showing that in the systems with initial radial velocity anisotropy: 1) mass segregation is slower in the inner regions and more rapid in the outer regions, 2) the rate of disruption of primordial binaries is higher, and 3) the rate of binary exchange events is enhanced compared to the isotropic systems and may lead to an increased dynamical formation of binaries including a stellar remnant component.
52nd DDA Meeting
Star cluster evolution towards energy equipartition
The presented work explores the evolution towards energy equipartition in models of star clusters with different initial degrees of velocity anisotropy. Our analysis has revealed several novel dynamical aspects, such as the rate of evolution towards energy equipartition depends on the initial degree of radial velocity anisotropy, and differs for the radial and the tangential components of the velocity dispersion. We have also found that the outermost regions of the initially isotropic system evolve towards a state of 'inverted' energy equipartition, which means that high-mass stars have a larger velocity dispersion than low-mass stars. This is due to the dependence of the tangential velocity dispersion on the stellar mass the radial velocity dispersion shows no anomaly. Finally, we focused on the effects of different strengths of the Galactic tidal field and the role of primordial binaries. Our results shed further light on the link between the clusters' internal kinematics, their formation and evolutionary history, and also add new fundamental elements to the theoretical framework needed to interpret the observational studies of stellar kinematics in globular clusters.
Grants and Funding
Scientific
2024 – 2026
PI of "ECLIPSE: Exploring Compact stellar remnants and their Impact on Star Clusters Evolution"
part of Marie Skłodowska-Curie Actions -- COFUND, project "MERIT" -- Grant agreement ID 101081195
2016 – 2018
PI of "Perturbed stellar motions in dense star clusters"
Grant Agency of Charles University, project GAUK-186216
2013
Trainee of ESAC project "Searching for a 'runaway-mass' black hole in the Orion Nebula Cluster"
PIs: M.~Guianazzi, J.~Svoboda, H.~Bouy (declined due to personal reasons)
Computational time
2022 – present
PI of "Dynamical evolution of star clusters with anisotropic velocity distributions"
Indiana University Information Technology Services
CPUs and GPUs, with extended 15 TiB quota
2014 – present
Access to the Czech national grid MetaCentrum (MetaVO, Cesnet, e-INFRA)
CPUs, 30 TiB quota, used 5 000+ CPU-days
yearly evaluation
2014 – 2016
Access to the "KK" computer cluster of the Department of Physics, Charles University, Prague