1. Star Formation in thin Disks of Spiral Galaxies Seen Face-On

   • V. E. Karachentseva
   • I. D. Karachentsev
   • O. G. Kashibadze

   OriginalPaper 10 June 2020 Pages: 151 - 165

2. Activity Types of Galaxies Selected from an HRC/BHRC Sample. II

   • G. M. Paronyan
   • A. M. Mickaelian
   • G. A. Mikayelyan

   OriginalPaper 10 June 2020 Pages: 166 - 178

3. Kinematics and Velocity Ellipsoid of Halo Red Giants

   • M. I. Nouh
   • W. H. Elsanhoury

   OriginalPaper 10 June 2020 Pages: 179 - 189

4. Orbital Solution of Some Contact Binaries

   • M. M. Elkhateeb

   OriginalPaper 10 June 2020 Pages: 190 - 199

5. Variations in the Period of Negative Superhumps in SU UMa-Type Dwarf Novae. I. Mn Dra (2012-2017)

   • A. S. Sklyanov
   • E. P. Pavlenko
   • A. G. Gutaev

   OriginalPaper 10 June 2020 Pages: 200 - 216

6. New Optical and Infrared Photometric Study of Young Open Star Cluster NGC 7790

   • A. A. Haroon
   • R. M. Alrehaili
   • H. A. Ismail

   OriginalPaper 11 June 2020 Pages: 217 - 227

7. Photometric Studies of the Intermediate Polar DO Dra in 2008 and 2019

   • Ju. V. Babina
   • E. P. Pavlenko
   • M. V. Andreev

   OriginalPaper 10 June 2020 Pages: 228 - 242

8. The Massive Binary System RY Sct – New Solution of the Light Curves

   • N. Kochiashvili
   • I. Kochiashvili
   • M. Vardosanidze

   OriginalPaper 10 June 2020 Pages: 243 - 251

9. Preflare Dynamics of Microwave and Ultraviolet Emission in Active Regions of the Sun

   • I. A. Bakunina
   • V. F. Melnikov
   • A. S. Morgachev

   OriginalPaper 10 June 2020 Pages: 252 - 259

10. Dynamics of Electric Current’s Parameters in Active Regions on the Sun and Their Relation to the Flare Index

    • Yu. A. Fursyak
    • V. I. Abramenko
    • A. S. Kutsenko

    OriginalPaper 11 June 2020 Pages: 260 - 273

11. Fine Filament Structure of a Quiescent Solar Prominence

    • O. A. Korolkova
    • A. A. Solov’ev

    OriginalPaper 11 June 2020 Pages: 274 - 281

12. Study of the Periodicities of the Solar Differential Rotation

    • D. Japaridze
    • G. Dumbadze
    • B. Chargeishvili

    OriginalPaper 17 June 2020 Pages: 282 - 287

13. Fractal Dimension of the Cosmic Microwave Background as a Test of "Planck" Spacecraft Data

    • P. A. Tarakanov
    • M. Y. Yezhkov
    • M. V. Kostina

    OriginalPaper 15 June 2020 Pages: 288 - 295

14. New Solutions Generating Technique to Generalized Kompaneets Equation and the Corresponding Heun Functions

    • M. A. Dariescu
    • C. Dariescu

    OriginalPaper 15 June 2020 Pages: 296 - 306