Grankin Konstantin Nikolaevich General data:
Born: 23.11.1961
Place of birth: Saratov city, Saratov region, Russian SSR
Studied in: M. G. Chernyshevsky Saratov State University (1984);
Key interests: informatic technologies, photometry, variable stars, non-stationary stars, stellar systems. PhD Thesis: Study of rotational modulation in young nonstationary stars (1995 );
Biography:
He was born on November 23, 1961 in Saratov city of Saratov region of the Russian SSR.
He graduated from M. G. Chernyshevsky Saratov State University in 1984.
He was an employee of the Astronomical Institute (Uzbekistan) during 1987-2007. During this time he went from senior engineer to head of the department of variable stars.
In 1995 he defended his dissertation on the topic: "Study of rotational modulation in young nonstationary stars".
Since 2007 he has been working at the Crimean Astrophysical Observatory, since 2013 he has been the head of the Department of Star Physics. His scientific work is related to the photometry of various variable stars, including T Taurus (TTS), Herbig (AE / Be) and other young stars that have recently passed the TTS (PTTS) stage. He took an active part in photometric observations performed under the ROTOR program at the Maidanak Observatory in Uzbekistan during 1987-2007. As a result of this program, a unique photometric database containing more than 100,000 UBVR measurements for 370 objects different areas of star formation. He created a package of programs that implement various methods of statistical and periodogram analysis of astronomical time series. He identified six candidates for close binary systems among several dozen young stars and found quasi-cyclic variations in brightness in 38 NAeVe. He found rotational gloss modulation through spots in 88 TTS. He showed that cyclic and quasi-cyclic photometric variability of NAeVe can be due to the existence of orbital structures of different origins. He studied in detail the properties of spot rotational modulation in sixty TTS with weak emission lines (WTTS) of the Taurus-Chariot star-forming regions. He determined the size and temperature of the stained areas in several WTTS and traced the evolution of these parameters over time. He discovered the phenomenon of stability of initial epochs and periods of rotation for 17 WTTS in the time interval from 5 to 19 years. This stability indicates that the active region of each WTTS remains on a certain meridian for many years. He found that a significant change in the amplitude of the brightness curves of the spotted WTTS is not accompanied by a significant change in the average level of brightness. The simulation showed that the decrease in the amplitude of brightness modulation is not due to a decrease in the total area of the spots, but to a more uniform distribution of the spots on the stellar surface. This conclusion was later confirmed by Doppler mapping of the surface of the selected WTTS, performed by K. M. Grankin together with the French astronomer J.-F. Donati. He co-authored a series of works by the French astronomer J. Bouvier, devoted to the study of AA Tai, which allowed a detailed study of the processes of magnetospheric accretion under the control of the magnetic field of the young star. During 1979-2015 he became the author of 120 scientific articles.
The scientist is a member of the European Astronomical Society. He received the title of "Honored Worker of Science and Technology of the Republic of Crimea".
Sources:
1 Àñòðîíîìû Ðîññèè 1917-2017/ íàó÷. ðåä. À.Ì.×åðåïàùóê, Êàçàíü, Êàçàí. ôåä. óí-ò, 2017.- 568ñ- C.120
