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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Publications of The Korean Astronomical Society
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The Korean Astronomical Society
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Volume & Issues
Volume 16, Issue 1 - Dec 2001
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THERMODYNAMICS, ELECTRODYNAMICS, AND 'H-R DIAGRAM' OF BLACK HOLES
PARK SEOK JAE ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 1~5
In this review article we introduce the 'H-R diagram' of black holes. Some fundamental concepts of black hole thermodynamics and electrodynamics are also summarized in detail.
SACHS-WOLFE EFFECT IN PERTURBED BIANCHI TYPE I UNIVERSE
SONG D. J. ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 7~10
In the framework of the C-gauge condition for the perturbed variables and the linear approximation for the anisotropy of the spacetime, we studied the formulae for the Sachs-Wolfe effect in dust filled and perturbed Bianchi type I universe model. The results were compared with those of the flat Friedmann model.
STATIONARY, AXISYMMETRIC BLACK HOLE MAGNETO SPHERES IN OBLATE SPHEROIDAL COORDINATES
PARK SEOK JAE ; FLETCHER ANDRE B. ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 11~14
In this paper, we simplify the equations of the Macdonald-Thome black hole magnetosphere. Our major assumption is that the 3-D electric and magnetic flux isosurfaces respectively form families of confocal oblate spheroids and hyperboloids. As a result, the magnetospheric equations are greatly simplified, and may provide a useful framework for instances when rigorous, theoretical approaches are not necessary.
OBSERVATIONS OF THERMAL TRANSITIONS OF SiO TOWARD THE SGR A MOLECULAR CLOUD
MINH Y. C. ; ROH D.-G. ; KIM S. J. ; OHISHI M. ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 15~20
We observed the thermal transitions of SiO (J=I-0, 2-1) and
(J=l-O) toward the Sgr A molecular clouds. The distribution and the velocity structure of SiO are very similar to previous results for 'quiet' interstellar molecules. We think· that the SiO has been well mixed with other molecules such as
which may indicate that the formation of Sgr A molecular clouds was affected by the activities, such as shock waves or energetic photons, from the Galactic center in large scales. The total column density of SiO is about
and the fractional abundance
appears to be about 10 times larger than those of other clouds in the central region of our galaxy. The derived values are thought to be lower limits since the optical depths of the observed SiO lines are not very thin. The formation of SiO has been known to be critically related to shocks, and our results provide informative data on the environment of our Galactic center.
SOLAR EPHEMERIS BY DE405
KIM HYO RYOUNG ; ROH DUK GYOO ; CHUNG HYUN SOO ; JUNG JAE HOON ; CHO SE HYUNG ; AHN YOUNG SOOK ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 21~23
The DE405 ephemeride is introduced as TRAO solar ephemeris system to support the apparent coordinates of planets after 2000. The time delay between planets and observer has to be regarded to get the apparent position of planet. Some fast algorithms about time delay are suggested to reduce the computing time. The CSI method is applied to run these algorithms on any O/S including both real-time and run-time machine.
BOAO, CCD COLOR IMAGES I
JEON YOUNG-BEOM ; KIM BONG-GYU ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 25~29
We obtained three-color composite. images of 78 celestial objects most of which are listed in Messier catalogue. In order to make color images, 118 raw image sets were taken with B, V, R, I and H-alpha filters. We used the 2k CCD camera attached to the 1.8 m telescope of Bohyunsan Optical Astronomy Observatory. These composite images are to be used for educational purposes or public releases. The images are presented on the website, http://www.boao.re.kr/-ybjeon/boao_images.htrnl.
CHARACTERISTICS OF THE BOAO 2K CCD CAMERA
PARK BYEONG-GON ; CHUN MOO-YOUNG ; YUK IN-SOO ; SEONG HYEON-CHEOL ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 31~36
We present the characteristics of the 2K CCD camera at the Bohyunsan Optical Astronomy Observatory of the Korea Astronomy Observatory at the time of its development. The purpose of this paper is to support the observers who may need detailed information on the characteristics of the camera and to provide helpful information on the optimization' of a CCD camera for those who try to develop their own camera. The 2K CCD camera was optimized to have a gain of
and a read out noise of
from an experiment using radioactive
X-ray source. The charge transfer efficiency was measured as 0.9999976 for serial and 0.9999942 for parallel direction, which means
charge loss along the serial direction and
along the parallel direction across the chip. The quantum efficiency of the camera was measured from an experiment using a homogeneous light source consisting of a halogen lamp and an integrating sphere with a monochromator. The resulting quantum efficiency of the camera peaked at the wavelength range 600-700 nm with the value of
AN OBSERVATION PROGRAM FOR THE SOAO 2K CCD CAMERA
KIM SEUNG-LEE ; KYEONG JAE-MANN ; KWON SUN-GIL ; YOUN JAE-HYOUK ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 37~42
We developed an observation program for a 2K CCD camera, which was newly attached at the SOAO (Sobaeksan Optical Astronomy Observatory) 61cm telescope. The program was designed to control the telescope as well as the CCD camera and to monitor the CCD image quality, with very easy under the window-based graphical user interface (GUI). Furthermore, applying the automated differential photometric algorithm, we can obtain the instrumental magnitudes of several variable and comparison stars in real-time. Simultaneous photometry enables us to get precise differential magnitudes of variable stars even if the weather condition is not photometric. This new observation system has been using for many astronomical observations from September, 2001.
DEVELOPMENT OF CCD CAMERA FOR OBSERVING WIDE FIELDS
YU YOUNG SAM ; PAK SOOJONG ; KIM MINJIN ; LEE SUNGHO ; BYUN YONG-IK ; CHUN MOO-YOUNG ; HAN WONYONG ;
Publications of The Korean Astronomical Society, volume 16, issue 1, 2001, Pages 43~47
We developed a CCD camera that can observe wide fields on the sky. We tested the field of views using various lenses. For cooling the CCD chip, we used a thermoelectric cooling device and tested the cooling efficiency. This camera will continuously observe a part of the sky. The data from the camera will be used to decide the current weather condition by the real-time star counting program (SCount) which will be developed later.