University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Long term variability of the coronal and post – coronal regions of the Oe star HD (ζ Oph) Antoniou, A. 1, Danezis, E. 1, Lyratzi, E. 1, Nikolaidis, D. 1, Popović, L. Č. 2 & Dimitrijević, M. S University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics, Panepistimioupoli, Zographou , Athens – Greece. 2. Astronomical Observatory, Volgina 7, Belgrade, Serbia.

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade C IV N IV N V λ Å λ Å λ Å λ Å λ Å

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Vrot, Vrad, Vrand: Constant with time Rotational Velocities : a component: 1400 km/s b component: 950 km/s Radial Velocities : a component: -800 km/s b component: -700 km/s Random Velocities : a component: 320 km/s b component: 90 km/s C IV regions

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Column Density (CD) in cm -2 of each one of the C IV resonance lines for the independent density regions of matter which create the satellite components. λ Å a component: 2.15×10 10 cm -2 b component: 0.72×10 10 cm -2 λ Å a component: 1.98×10 10 cm -2 b component: 0.66×10 10 cm -2

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade N IV region GR method V rad, V rand, CD: Constant with time Radial Velocities : -47 km/s Random Velocities : 262 km/s Column Density : 1.09×10 10 cm -2

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade N V regions GR method V rad, V rand : Constant with time Radial Velocities : a component: km/s b component: km/s c component: km/s Random Velocities : a component: 797 km/s b component: 152 km/s c component: 71 km/s

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Column Density (CD) in cm -2 of each one of the N V resonance lines for the independent density regions of matter which create the satellite components. λ Å a component: 1.13×10 10 cm -2 b component: 0.25×10 10 cm -2 c component: 0.07×10 10 cm -2 λ Å a component: 1.03×10 10 cm -2 b component: 0.23×10 10 cm -2 c component: 0.06×10 10 cm -2

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade A statistical study of physical parameters of the C IV density regions in 20 Oe stars Antoniou, A. 1, Danezis, E. 1, Lyratzi, E. 1, Nikolaidis, D. 1, Popović, L. Č. 2 & Dimitrijević, M. S University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics, Panepistimioupoli, Zographou , Athens – Greece. 2. Astronomical Observatory, Volgina 7, Belgrade, Serbia.

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Rotational Velocities : a component: 1458 km/s b component: 821 km/s c component: 251 km/s d component: 133 km/s e component: 65 km/s Radial Velocities : a component: km/s b component: km/s c component: km/s d component: -469 km/s e component: -80 km/s

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Random Velocities : a component: 187 km/s b component: 163 km/s c component: 130 km/s d component: 108 km/s e component: 56 km/s FWHM : a component: 13.0 Å b component: 6.2 Å c component: 2.2 Å d component: 1.2 Å e component: 0.4 Å

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Absorbed Energy (E) λ Å a component: 5.18 eV b component: 3.21 eV c component: 1.39 eV d component: 0.53 eV e component: 0.24 eV λ Å a component: 4.76 eV b component: 2.85eV c component: 1.26 eV d component: 0.48 eV e component: 0.22 eV

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Column Density (CD) λ Å a component: 5.65 ×10 10 cm -2 b component: 4.58 ×10 10 cm -2 c component: 3.65 ×10 10 cm -2 d component: 2.62 ×10 10 cm -2 e component: 1.17 ×10 10 cm -2 λ Å a component: 5.54 ×10 10 cm -2 b component: 4.39 ×10 10 cm -2 c component: 3.56 ×10 10 cm -2 d component: 2.56 ×10 10 cm -2 e component: 1.17 ×10 10 cm -2

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade The N IV region in the spectra of 20 Oe stars Antoniou, A. 1, Danezis, E. 1, Lyratzi, E. 1, Nikolaidis, D. 1, Popović, L. Č. 2 & Dimitrijević, M. S University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics, Panepistimioupoli, Zographou , Athens – Greece. 2. Astronomical Observatory, Volgina 7, Belgrade, Serbia.

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Two levels of Vrad, Vrand, FWHM Radial Velocities First level: -350 and -150 km/s Second level: -70 km/s Random Velocities First level: 350 and 220 km/s Second level: 150 and 50 km/s FWHM First level: 5 and 3 Ǻ Second level: 2 and 1 km/s Ǻ

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Two levels of Absorbed Energy and Column Density Absorbed Energy (E) First level: 2 and 1.2 eV Second level: 0.6 and 0.4 eV Column Density (CD) First level: 4.5×10 10 cm -2 and 3×10 10 cm -2 Second level: 2.5×10 10 cm -2

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Investigation of the post coronal density regions of Oe stars, through the N V UV resonance lines Antoniou, A. 1, Danezis, E. 1, Lyratzi, E. 1, Nikolaidis, D. 1, Popović, L. Č. 2 & Dimitrijević, M. S University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics, Panepistimioupoli, Zographou , Athens – Greece. 2. Astronomical Observatory, Volgina 7, Belgrade, Serbia.

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Vrot:1st level: 1800 and 1100 km/s 2nd level: 400 and 200 km/s Vrad:1st level: and km/s 2nd level: -500 and -100 km/s Vrand:1st level: 400 and 200 km/s 2nd level: 150 and 80 km/s FWHM: 1st level: 18 and 10 Å 2nd level: 6 and 2 Å

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Two levels of Absorbed Energy (E) λ Å First level: 7 and 3 eV Second level: 1 and 0.5 eV λ Å First level: 6.3 and 2.7 eV Second level: 0.9 and 0.45 eV

University of Athens, Faculty of Physics, Department of Astrophysics, Astronomy and Mechanics Astronomical Observatory of Belgrade Two levels of Column Density (CD) λ Å First level:5×10 10 cm -2 and 3×10 10 cm -2 Second level: 2.5×10 10 cm -2 λ Å First level: 4.45×10 10 cm -2 and 2.7×10 10 cm -2 Second level: 2×10 10 cm -2

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