간행물
천문학회지 KCI 등재 SCOPUS Journal of The Korean Astronomical Society
- 발행기관 한국천문학회
- 자료유형 학술지
- 간기 반년간
- ISSN 1225-4614 (Print)2288-890X (Online)
- 수록기간 1968 ~ 2024
- 주제분류 자연과학 > 천문학 자연과학 분류의 다른 간행물
- 십진분류KDC 440DDC 520
권호리스트/논문검색
제8권 제1호 (1975년 12월) 7건
1.
1975.12
구독 인증기관·개인회원 무료
An improved version of the galatic mass distribution has been derived by increasing the number of shells in each spheroid of our earlier model. It is found that the increase of the number of the shell improves the model considerably, thus making it agree far better with observations.
2.
1975.12
구독 인증기관 무료, 개인회원 유료
Densities of the three constituent spheroids of the same eccentricity as our earlier model of the Galaxy are assumed to be given by an analytical form of ρ i (r)= k i e − m i r u i , where k i , m i , and α i are obtained by comparing with the results of the previous model. Using three values of ρ i (r) the galactic rotation curve, mass of each spheroid and the whole Galaxy are calculated, and the three dimensional density distribution in the Galaxy is also obtained. The calculated rotation curve of the model Galaxy is in good agreement with the observed curve, and the shape of the cross section of the model Galaxy given by the computed density is very similar to the inferred shape of the spiral galaxies.
4,000원
3.
1975.12
구독 인증기관 무료, 개인회원 유료
Photoelectric observations were made of four N stars (HD 51208, HD 75021, V 1942 Sgr, and RU Vir) at careful1y chosen discrete wavelengths between 7000 |AA a n d 11000 |AA with 30 |AA bandpass width. Their effective temperatures have been derived by fitting the black-body radiation curve to the observed continuum intensities at 7800 |AA , 9000 |AA a n d 10800 |AA . The resulting temperature ranges from 2500˚ K t o 2900 ˚ K . . It is probable that almost all the N stars belong to this range of temperature. However, the temperatures of very red N stars can not be well determined due to large variability and redistribution of their radiation energy arising from the graphite shells around them.
3,000원
4.
1975.12
구독 인증기관 무료, 개인회원 유료
A new technique of photographic observations is developed for the determination of time of minimum light of eclipsing binary. An instrumental system to accomplish the observation is described. With this instrument the atmospheric extinction coefficients in Seoul are observed, and four times of minimum light for Algol and W UMa are determined.
4,000원
5.
1975.12
구독 인증기관 무료, 개인회원 유료
A time of minimum light for VV Orionis has been determined photographically using techniques developed by Jeong. The observed time of minimum light shows that VV Ori exhibits a constant orbital period. The O-C computed with the light elements given by Eaton is found to be − 0 d , 0070. An attempt to correct for night-to-night shifts for plates taken on three nights in February and March 1975, was unsuccessful and thus the complete light curve initially planned was not obtained.
3,000원
6.
1975.12
구독 인증기관 무료, 개인회원 유료
Solar electrical conductivity has been calculated, making use of Yun and Wyller's formulation. The computed results arc presented in a tabulated form as functions of temperature and pressure for given magnetic field strengths. The results of the calculation show that the magnetic field does not play any important role in characterizing the electrical conductivity of the ionized gas when the gas pressure is relatively high (e.g., P ≥ 10 4 d y n e s / c m 2 ). However, when the gas pressure is low (e.g., P ≤ 10 d y n e s / c m 2 ), the magnetic field becomes very effective even if its field strength is quite small (e.g., B ≤ 0.01 gauss). It is also found that, except for lower temperature region (e.g., T ≤ 10 4 ∘ K ), there is a certain linear relationship in a log- log graph between the pressure and the critical magnetic field strength, which is defined as a field strength capable of reducing the non-magnetic component of the electrical conductivity by 20%.
4,000원
7.
1975.12
구독 인증기관 무료, 개인회원 유료
Effect of the ratio of mixing length to the pressure scale-height α =l/HP on the effective temperature has been investigated under some simplifying assumptions. The result is compared with that of the existing model calculations. The role of convection zone in the stellar evolution is briefly summarized.
4,000원
