[천문대 세미나 개최 안내] 5.16(월) 16:30-18:30, 5.17(화) 16:30- (총 2회, 대면 및 비대면 병행)
세미나 주제 및 일정은 다음과 같으며 하이브리드(대면/비대면) 형식으로 진행합니다.
(Zoom 주소는 추후에 안내드리겠습니다)
Seminar Title : 우주와 국방
Speaker : 황홍연 박사 (LIG넥스원 연구위원) : "위성 개발시 고려 사항"
이석희 대표 (C&I Global Consulting): "우주와 국방, 글로벌 경쟁력 관점에서"
When and where : May.16 (Mon) 16:30-18:30, Kyung Hee Observatory Auditorium
Seminar Title : The corona of the Sun as an active medium for magnetoacoustic waves
Speaker : Prof. Valery Nakariakov (University of Warwick, UK)
When and where : May. 17 (Tue) 16:30, Kyung Hee Observatory Auditorium
The existence of the corona of the Sun at the observed high, over one million K temperature requires an energy supply which counteracts losses by radiation and thermal conduction. The mechanism for the energy supply, i.e., the coronal heating mechanism remains unknown and is subject to intensive debates. A promising way for revealing properties of the heating mechanism is offered by the modification of magnetoacoustic waves by the perturbed thermal balance between heating and cooling. The wave-induced thermal misbalance (TM) represents an additional natural mechanism for the exchange of energy between the plasma and the wave. TM makes the corona an active medium for magnetoacoustic waves. In particular, the wave can either gain energy from the coronal heating source (c.f. burning gases, lasers and masers), or experience enhanced damping. We review recent achievements in this newly emerging research field, focussing on the effects of TM on slow magnetoacoustic waves. These new effects include enhanced frequency-dependent damping or amplification of slow waves, and wave dispersion caused by the presence of characteristic, TM time scales in the system. We also discuss the possibility to probe parameters of the unknown coronal heating function by observations of slow waves and linear theory of thermal instabilities. The manifold of the new properties that slow waves acquire from a thermodynamically active nature of the solar corona indicate a clear need for accounting for the effects of combined coronal heating/cooling processes not only for traditional problems of the formation and evolution of prominences and coronal rain, but also for an adequate modelling and interpretation of magnetohydrodynamic waves."