Yakiv Pavlenko
Stay at the IAC: 03/09/2016 a 29/10/2016
Research line: Exoplanets and Solar System
Dr. Pavlenko gave a Seminar at the IAC on 2013 May 16th entitled Molecular Astrophysics.
Dr. has developed his career as a researcher at the Main Astronomical Observatory (MAO) of the National Academy of Sciences of Ukraine. Currently he is the Chief Research Fellow of the MAO and has the official status of the Visiting Research Fellow in the University of Hertfordshire (United Kingdom).
His main scientific interests are spectroscopy Brown Dwarfs, Ultracool Dwarfs, Evolved Stars, Temporal Changes of Abundances of Li, C, N, O and other elements, Isotopic Ratios, Model Atmospheres, Modelling of Optical and IR Spectra and SEDs of Late-type Stars and BDs, NLTE. In 2011 he received the Barabashov prize of the National Academy of Sciences of Ukraine.
Prof. Pavlenko has been participating in two european FP7 projects as a leader of the MAO's node: Rocky Planets Around Cool Stars (Marie Curie Initial Training Networks, ITN) and POSTAGBinGALAXIES—Evolved stars: clues to the chemical evolution of galaxies (Marie Curie Actions—International Research Staff Exchange Scheme, IRSES).
The objective of the visit by Prof. Yakiv Pavlenko to the IAC was devoted to model the spectra of young L dwarfs in open clusters, in collaboration with Dr. Víctor Sánchez Bejar and other members of the group of Exoplanets and Astrobiology. Their recent investigations in the sigma Orionis cluster allowed to identify 20 new isolated planets. They have carried out a spectroscopic follow up of these objects using ISAAC at VLT and Osiris at GTC and have determined that they have a L spectral type (effective temperatures of 2000-1800K), showing different features from field dwarfs, which can be attributed to low gravity. Spectral synthesis of these objects are required to explain these differences and confirm their low gravity, and hence, their youth. This analysis will be included in a forthcoming paper about the spectroscopic characterization of isolated planets in the sigma Orionis cluster.
During his visit, Prof. Yakiv Pavlenko also worked in other projects: the spectral synthesis of very cool objects with effective temperatures of 300-600K, the so called Y dwarfs, and the L and T-type Luhman16AB binary, which are the closest brown dwarfs to our Sun. These latter results will be included in another paper in preparation with X-Shooter data of this system.
