• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.761-763
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• 2015

Colors have been derived from the observed optical spectrum of Mars and Jupiter. It is known that the planets and the Moon emit reflected sunlight and thus their spectra are similar to the spectrum of solar radiation. The question was then why is the color of Mars different from that of other planets, i.e. red, although it would share the same spectrum of reflected sunlight. Can one derive color from the spectrum? Therefore, we observed the optical spectra of the scattered sunlight in day time for the Moon and Mars using a 1-D array spectrograph on the 12-inch reflecting telescope in the Korea Science Academy of KAIST in Busan, Korea. We adopted the International Commission on Illumination (CIE) in 1931 of three spectral sensitivity peaks for the human eye in short, medium and long wavelengths in visible light. The observed spectra were imposed on CIE sensitivities and the color detected by the human eye was derived. The Mars spectrum represents red color and the Moon white. It is a similar color to that which a human would see. This result means that color is easily derived from astronomical spectra. The appearance of the planets surface can be determined for Mars, which is the result of iron oxide.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.109.1-109.1
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• 2012

In the past few years, two-planet circumbinary systems (e.g., HW Vir, NN Ser, DP Leo and HU Aqr) have been detected around short-period eclipsing binaries using ground-based telescopes. The existence of these planets has been inferred by interpreting the O-C variations of the mid-eclipse times. We have tested the orbital stability of these systems and propose to use Light Travel Time Effect (LITE) to detect such circumbinary planets from the ground. We generated synthetically the LITE signal of a two-planet circumbinary system with the aim to apply an analytic LITE model to recover the underlying synthetic system. To mimic a degree of realism inherent to ground-based observations, we added to the synthetic LITE data white noise with a Gaussian distribution and sampled the synthetic LITE signal randomly. We successfully recovered the original system demonstrating that two-planet circumbinary systems can be detected using ground-based telescopes, provided the timing measurements of the mid-eclipses are sufficiently accurate and the observing baseline is long enough to ensure a sufficient coverage of all involved periods. We used HU Aqr as a test system and applied our model to its proposed planetary bodies considering near-circular orbits. We present the results of our calculations and discuss the LITE-detectability of a HU Aqr-like system.

• The Bulletin of The Korean Astronomical Society
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• v.25 no.2
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• pp.61-61
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• 2000

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.61-61
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• 2000

No Abstract, See Full Text

• The Bulletin of The Korean Astronomical Society
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• v.30 no.1
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• pp.22.1-22.1
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• 2005

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.81-84
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• 2005

We are undertaking an extra-solar planet search around G-type giant stars by means of Doppler technique using an iodine absorption cell installed to the high dispersion echelle spectrograph for the 188 cm reflector at Okayama Astrophysical Observatory (Okayama Planet Search Program, OPSP). Having detected the first planet candidate (Sato et al. 2003)the search has been proved very promising. Taking advantage of this success, we are trying to develop OPSP to an international collaborative work. We here report the current status of our efforts for establishing such collaborations, namely, those with Chinese and Korean astronomers. We also propose to establish an East-Asian network to search for extra-solar planets around G-type giant stars with the transit detecting technique as well as the Doppler technique, asking other persons/groups to join us to enjoy the planet search.

• Journal of Korean Elementary Science Education
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• v.21 no.1
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• pp.43-59
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• 2002

There has been a long debate whether the Sun revolves the Earth or the Earth revolves the Sun. Also, students are very interested in the solar systems, which means the entire system of planets, satellites, minor planets, comets, and meteoroids that orbit the sun. However, students are not sure about them. New models which enhance teaming about them are strongly needed. This study is intended to develop the new models on the solar systems and to investigate how the preservice elementary teachers' concepts are affected by them. Subjects are 20 preservice elementary teachers, One instrument including 11 items is used. Data are collected before using the new models and after using them through the tests. As a result, learning through the new models has a positive effects on the preservice elementary teachers' concepts on the solar system.

• Publications of The Korean Astronomical Society
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• v.16 no.1
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• pp.21-23
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• 2001

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.

• Journal of The Korean Astronomical Society
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• v.26 no.2
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• pp.135-139
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• 1993

Events of eclipses as well as other major astronomical events observable in the eastern sector of Asian continent are computed and checked with astronomical records of antiquity. Particular attention was given to two types of the events recorded in remaining records of Dangun Chosun Period (DCP): (1) concentration of major planets near the constellation of Nu-Sung $(\beta\;Aries)$ and (2) a large ebb-tide. We find them most likely to have occurred in real time. i.e., when the positions of the sun, moon, and planets happen to be aligned in the most appropriate position. For solar eclipses data, however, we find among 10 solar eclipse events recorded, only 6 of them are correct up to months, implying its statistical significance is no less insignificant. We therefore conclude that the remaining history books of DCP indeed contains important astronomical records, thereby the real antiquity of the records of DCP cannot be disproved.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.53.2-53.2
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• 2012

디지털 천체투영기의 보급은 천체투영관의 운영과 교육적 활용 방법에 변화를 가져왔다. 돔영상물 상영이 가능한 디지털 천체투영기를 도입한 천체투영관들의 교육적 활용을 높이기 위해서는 영상물을 활용한 교육 콘텐츠 개발이 선행되어야 하다. 이번 연구에서는 1)AMNH(American Museum of Natural History)에서 사용되고 있는 돔영상물의 교육자 매뉴얼들을 사례조사 하였고, 2)사례조사 결과와 2007 개정 과학과 교육과정을 고려하여 돔영상물 Planets(Astronef Production제작, 2010)의 교육자 매뉴얼을 개발 하였다. 개발된 Planets 교육자 매뉴얼의 활용은 개관 예정인 국립대구과학관과 국립광주과학관 천체투영관의 운영 활성화와 교육활동을 극대화 할 수 있을 것으로 기대된다. 또한 국내에서 수행중인 천문학 프로젝트(KVN, GMT, KMTNet, SKA 등)들의 교육자 매뉴얼 제작에 참고자료로 활용되길 기대한다.