Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of The Korean Astronomical Society
Journal Basic Information
Journal DOI :
The Korean Astronomical Society
Editor in Chief :
Volume & Issues
Volume 23, Issue 2 - Dec 1990
Volume 23, Issue 1 - Jun 1990
Selecting the target year
CO OBSERVATIONS OF A REGION IN THE PERSEUS ARM CONTAINING Hb 12 AND ITS IMMEDIATE VICINITY
Cho, Se-Hyung ; Kim, K.T. ;
Journal of The Korean Astronomical Society, volume 23, issue 2, 1990, Pages 85~96
observations of the region containing the planetary nebula Hb12 were made with the Nobeyama Radio Telescope. These observations reveal that there is no significant CO emission from Hb 12 itself. Near Hb 12, however, the observed regions show a structure of clustered dark clouds whose physical parameters suggest that these clumps would be further fragmented or collapesed. Also found with the high resolution observations is that a few isolated clumps are located away from the main CO feature extended possibly from the galactic plane. For more detail morphologies and velocity structures of the clumps, especially in relation to the large CO complex to which these are likely to be associated, more observations are substantiated.
TIDAL DENSITIES OF GLOBULAR CLUSTERS AND THE GALACTIC MASS DISTRIBUTION
Lee, Hyung-Mok ;
Journal of The Korean Astronomical Society, volume 23, issue 2, 1990, Pages 97~105
The tidal radii of globular clusters reflect the tidal field of the Galaxy. The mass distribution of the Galaxy thus may be obtained if the tidal fields of clusters are well known. Although large amounts of uncertainties in the determination of tidal radii have been obstacles in utilizing this method, analysis of tidal density could give independent check for the Galactic mass distribution. Recent theoretical modeling of dynamical evolution including steady Galactic tidal field shows that the observationally determined tidal radii could be systematically larger by about a factor of 1.5 compared to the theoretical values. From the analysis of entire sample of 148 globular clusters and 7 dwarf spheroidal systems compiled by Webbink (1985), we find that such reduction from observed values would make the tidal density (the mean density within the tidal radius) distribution consistent with the flat rotation curve of our Galaxy out to large distances if the velocity distribution of clusters and dwarf spheroidals with respect to the Galactic center is isotropic.
TWO UNITARY LIGHT CURVES OF AR LACERTAE IN 1984
Park, Hong-Suh ; Chen, Kwan-Yu ;
Journal of The Korean Astronomical Society, volume 23, issue 2, 1990, Pages 106~111
Photoelectric observation in 1984 shows light variation outside eclipses. The effect of the changing ambient temperature on the light curves were studied. Difficulty of studying and unitary, or mean, light curve of AR Lac is stressed.
EVOLUTION OF AN ASPHERICAL VOID
Lee, Hae-Shim ; Koh, Yoon-Suk ;
Journal of The Korean Astronomical Society, volume 23, issue 2, 1990, Pages 112~115
We test an evolution of a giant void using an N-body simulation. We find the void expansion is faster than the rest part of the universe and the shape of an isolated aspherical void becomes more spherical as it evolves.
THE GROWTH OF A PRIMORDIAL BLACK HOLE AT THE CENTER OF A STAR
Park, Seok-Jae ;
Journal of The Korean Astronomical Society, volume 23, issue 2, 1990, Pages 116~121
It has been suggested that there could be a large number of primordial black holes which were formed in the early universe. We analyze the growth of such a primordial black hole following two different accretion rates - the Eddington accretion rate and the Bondi accretion rate - at the center of a host star like the sun. We find that a primordial black hole with M <
cannot substantially grow in any case throughout the lifetime of a host star. If M >
, the evolution of a host star depends entirely on the mode of accretion, but it ends as a black hole in either case. Since more stars may have primordial black holes at the center of a galaxy this may result in a cluster of such black holes, and the cluster may eventually collapse to produce a single supermassive black hole.