We have carried out the high-resolution spectroscopic observations of Titan using BOES (Bohyunsan Echelle Spectrometer) to establish a standard spectral atlas of Titan. The observations were made on November 3, 4, 16 and 17, 2003 using a 300 11m fiber optics with a spectral resolving power of 30,000. The spectral atlas will be served as a reference for the future spectroscopic researches of Titan and other planetary objects. We were able to confirm CH4 absorption lines of the Kuiper bands, and find unidentified lines near 7500 Å

We observed the thermal transitions of SiO (J=I-0, 2-1) and 29SiO (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 H2 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 4.1×1014cm−2 and the fractional abundance SiO/H2 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.

We have presented detected molecules, atoms, radicals, ions, and dimers in the atmospheres of planets and comets from Earth-based and spaceborne observatories during the last 3 decades. We have reviewed spectroscopic studies on the auroral emissions and air glows of the giant planets, and briefly summarized spectroscopic observations of dimers in the atmospheres of the giant planets and Titan. In particular, we highlighted the recent detections of new molecular emissions and absorptions in the spectra of the giant planets, Titan, and recent bright comets from spaceborne or ground-based observatories. We also reviewed current models and theories of the origin and evolution of the solar system, and implications of isotopic ratios in these atmospheres.

We have investigated future large telescopes, which should represent the next generation of Korean optical and infrared telescopes. We first studied the history of the development of large telescopes in the USA, European countries, and Japan. Based on these studies, we came up suitable Korean large telescopes, which fit the current status of Korea in terms of financial situation, required technology, sciences, and manpower. We presented the potential impacts of developing large telescopes on the relevant Korean industry and Korean astronomical society. We also discussed a possibility to install large Korean telescopes at foreign sites utilizing highly competitive seeings and twice available observing dates there.

Observations of the J=1-0 transition line of HCN were made at the center of Comet C/1995 O1 (Hale-Bopp) from November, 1996 to April, 1997 with the 14-m radio telescope at the TRAO (Taeduk Radio Astronomical Observatory). From the obtained data, an HCN production rate at each observed date was derived. The rapid variation of the HCN production rate near the perihelion was detected, and it is thought to be caused by jet(s) from the nucleus. The correlation between the visual magnitude and the HCN production rate is found to be QHCN=27.03−0.11(mv−5logΔ) QHCN=27.03−0.11(mv−5logΔ) .

We obtained the CN(ΔV=0 ΔV=0 ) and C2(ΔV=0,±1 C2(ΔV=0,±1 ) spectra of comet Hale-Bopp(C/1995 O1) at the Kyunghee Observatory and Bohyunsan Astronomical Observatory between March 7 and May 12, 1997 The fluxes for each molecular band were measured and then the production rates and column densities of CN and C2 C2 were calculated using a simple model. The resultantproduction rates of CN and C2 C2 are logQ(CN)=27.4 at r=0.94 AU(preperihelion) and logQ(C2)=27.3 logQ(C2)=27.3 at r=0.94 AU(postperihelion), respectively.