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1968년 ~ 2024년까지 1,211 건의 한국천문학회지를 격월간 확인하실 수 있습니다.
- The Korean Astronomical Society (The Korean Astronomical Society)
- 계간 (Quarterly)
- ISSN : 1225-4614 (ISSN : 1225-4614)
1225-4614
- DB구축현황 : 1,211건 (DB Construction : 1,211 Articles)
총 게시글 1,211건
페이지 117/122
1161
- 나일성
- 天文學會誌 = The journal of the Korean Astronomical Society
- 12, n.1
- pp.35-40
- 1979
- 원문 바로보기
Astronomical records in the days of King Jeongjo of Yi dynasty, 1777-1800, are examined for solar and lunar eclipses, meteors and comets. The books used for this investigation are Sung Jeong Won Il Gi, which are the original daily records written in the court. The records found in these Sung Jeong Won Il Gi are tabulated according to the four astronomical phenomena above, and they were cross checked with the records in the book, Jung Bo Mun Heon Bi Go. Although Jung Bo Mun Heon Bi Go has most frequently been used as the original records to those who work for the ancient Korean records, the inaccuracy and the deficiency are found.
1162
- Kim, Yong-Duk
- 天文學會誌 = The journal of the Korean Astronomical Society
- 12, n.1
- pp.7-9
- 1979
- 원문 바로보기
The rate of gravitational quadrupole radiation is derived in the formalism of source theory. It is also shown that gravitational superradiance is theoretically possible.
1163
- Yun, Hae-Young
- 天文學會誌 = The journal of the Korean Astronomical Society
- 12, n.1
- pp.17-25
- 1979
- 원문 바로보기
The two methods for the derivation of helium abundance are presented. The magnitude of the largest bump along the red giant branch is fainter as helium abundance decreases and metal abundance increases. Using this relation and observed bump magnitude, the He-abundances of globular clusters are estimated. The another method is to use the relation that the ratio of asymptotic giant branch and horizontal branch stars increases with decreasing He-abundance. The comparison of the He-abundances derived from the two methods with those derived from the other two methods shows that they are consistent within the dispersion less than <TEX>${\Delta}Y=0.1$</TEX>.
1164
- Hong, Seung-Soo
- 天文學會誌 = The journal of the Korean Astronomical Society
- 12, n.1
- pp.27-34
- 1979
- 원문 바로보기
Temperature history of very small interstellar dust particles is followed under diffuse interstellar radiation. Because of extremely small thermal capacities of these grains with sizes ranging from a few tens to hundred Angstroms in radii, they are to experience strong fluctuations in temperature whenever they are hit by interstellar ultraviolet photons. Fluctuating temperature can inhibit these smaller component of interstellar dust from growing into core-mantle particles of submicron sizes by continuously evaporating atoms and molecules adsorbed on their surface. This is interpreted as a possible physical reason for the bimodal nature in grain size distribution. A brief discussion is also given to the far infrared emission properties of such small grains in diffuse interstellar dust clouds.
1165
- Chun, M.S.
- 天文學會誌 = The journal of the Korean Astronomical Society
- 12, n.1
- pp.11-15
- 1979
- 원문 바로보기
Four stars in the central region of 47 Tuc were observed spectroscopically using IPCS. The observed result showed that two asymptotic giant branch stars have the excess of nitrogen compared with the red giant branch stars, which indicates that the radial colour gradient in a globular clursters, at least for 47 Tuc, comes from the abundance gradient among the giant stars.
1166
- Yun, Hong-Sik
- 天文學會誌 = The journal of the Korean Astronomical Society
- 11, n.1
- pp.37-46
- 1978
- 원문 바로보기
A hydrostatic model atmosphere of a typical umbral core is constructed on the basis of both Na I <TEX>$D_2$</TEX> line profile and umbral core-to disk continuum intensity ratio. The observations were obtained by Mullan and Wyller with photoelectric means over the range from <TEX>$4000{\AA}\;and\;6500{\AA}$</TEX>. The computed line profile of Na I <TEX>$D_2$</TEX> and the emergent continuum intensity distribution are compared with the observations. The temperature of umbral cores is found to be lower by <TEX>$300^{\circ}K\;to\;500^{\circ}K$</TEX> than that of their ambient umbral region. The detailed physical structure of a working model of umbral cores is proposed.
1167
- 이은성
- 天文學會誌 = The journal of the Korean Astronomical Society
- 11, n.1
- pp.47-54
- 1978
- 원문 바로보기
Twelve Chih was sasigned to each day in the old Chinese calendar. This paper clarifres the relations between 12 Chih and the diurnal motion of Big Dipper or the clock, and it shows the long term table and formula for the dayly assignment of 12 Chih in the calendar.
1168
- Lee, See-Woo
- 天文學會誌 = The journal of the Korean Astronomical Society
- 11, n.1
- pp.1-30
- 1978
- 원문 바로보기
The four dimensional classification of globular dusters with the parameters, Z, Y, age and HB type is presented defining two new parameters. <TEX>$(B-V)_{1/2}\;and\;S_{3/2}$</TEX> which are shown to be tightly correlated with Kinman's spectral types and the helium abundances obtained from the R-method, respectively. The Z- and Y- abundances are derived from <TEX>$(B-V)_{1/2}\;and\;S_{3/2}$</TEX>, respectively, and the latter parameters determine the age class of clusters with help of Dickens' HB type, which is a function of Z. Y and age. For the examined forty two globular clusters the computed range at Z and Y are <TEX>$1.5{\times}10^{-4}{\leq}Z{\leq}4.5{\times}10^{-2}\;and\;0.23</TEX><TEX><</TEX><TEX>Y{\leq}0.41$</TEX>. The age difference between the oldest (HB type 1) and the youngest (HB type 7) clusters is roughly estimated to be <TEX>$2-4{\times}10^9$</TEX> years. Using these four parameters the known anomalous C-M diagrams seem to be reasonably interpreted without taking into account some complicate parameters such as unusually overabundant heavy elements, mass loss and mass spread, etc. The four dimensional scheme strongly suggests the slow successive collapses of the proto-Galaxy rather than a single fast collapse, and by this slow collapse model the inversion of chemical abundance gradient in the Galaxy can be explained. It is also shown that the clump position along the RGB near the HB level removes down to the fainter magnitude as the Z(Y)- abundance increases (decreases).
1169
- Beebe, Reta Fay
- 天文學會誌 = The journal of the Korean Astronomical Society
- 11, n.1
- pp.55-58
- 1978
- 원문 바로보기
An extensive molecular equilibrium calculation has been performed under sunspot conditions in order to resolve the current dispute on the presence of <TEX>$C_2$</TEX> lines in the spectrum of sunspots. Equilibrium abundance of <TEX>$C_2$</TEX> has been computed under the conditions of umbral cores, umbrae and the normal photosphere. As the results, it is found that the umbral cores yield unfavorable environment for <TEX>$C_2$</TEX> formation. It is concluded that <TEX>$C_2$</TEX> molecular lines are not likely tn be observed in the spectrum of sunspots.
1170
- Hong, Seung-Soo
- 天文學會誌 = The journal of the Korean Astronomical Society
- 11, n.1
- pp.31-36
- 1978
- 원문 바로보기
Although Serkowski used a single value K=1.15 in representing all the observed interstellar linear polarization curves by his empirical relation <TEX>$p({\lambda})/P_{max}$</TEX>=exp (-K <TEX>$1n^2({\lambda}_{max}/{\lambda})$</TEX>), where <TEX>$p_{max}$</TEX> is the maximum polarization at wavelength <TEX>${\lambda}_{max}$</TEX>, we have noticed a meaningful variation in K from observations of 72 stars. By comparing K's with <TEX>$P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$</TEX>, we have examined how the shape of the polarization curve is related with the degree of grain alignment on one hand, and with grain sizes on the other. We have shown that correlations between K, <TEX>$P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$</TEX>, are consistent with the idea of Davis-Greenstein mechanism for grain alignment.