An introduction to the first CCD camera system in Bohyunsan Optica1 Astronomy Observatory(CCD#l) is presented. The CCD camera adopts modular dewar design of IfA(Institute for Astronomy at Hawaii University) and SDSU(San Diego State University) general purpose CCD controller. The user interface is based on IfA design of easy-to-use QUI program running on the NeXT workstation. The characteristics of the CCD#l including Gain, Charge Transfer Efficiency, rms Read-Out Noise, Linearity and Dynamic range is tested and discussed. The CCD#l shows 6.4 electrons RON and gain of 3.49 electrons per ADU, and the optimization resulted in about 27 seconds readout time guaranteeing charge transfer efficiency of 0.99999 for both direction. Linearity test shows that non-linear coefficient is 6×10−7 6×10−7 in the range of 0 to 30,000 ADU.

We observed impact spots on Jupiter which were formed by the collision with fragments of Shoemaker-Levy 9 comet during the period from 17 July to 13 August, by using the SNU 61cm reflector combined with CCD camera and DBVRI filters. In order to get more clear image of impact spots, the observed data were processed by the unsharp masking method, high-pass filtering method and Richardson-Lucy algorithm after the basic processing through IRAF package. The sizes of impact spots range from 2000km to 1000km, and from this size, the original size of comet fragments before collision with Jupiter is estimated to be less than ∼3km ∼3km . From the observed rotating rate of impact spots, the rotational period of Jupiter is determined as 9h 9h 56m 56m 32s 32s at the southern latitude of 47∘∼49∘ 47∘∼49∘ .

We developed a real-time CCD photometric program for IBM PC compatibles. This program can perform several functions necessary for CCD photometry such as telescope control. filter rotation, CCD camera control and data acquisition, two-dimensional image processing, simple aperture photometry and automatic differential photometry. The image processing of a spiral galaxy M51 observed with the SNU 61cm reflector shows a well developed spiral structure. Simple aperture photometric results of 14 stars in open cluster NGC 6871 almost accorded with those from IRAF/APPHOT. And we could confirm the light variation of eclipsing binary EM Cep by simultaneous automatic differential photometry of 7stars in NGC 7160. Due to the excellence in the precision and efficiency of automatic differential photometry using CCD. this program is very useful for the study of small amplitude δ δ Sct type variables and of the photometric stability of B ∼ ∼ F type stars.

낱별의 광전측광 관측을 위하여 두 가지 컴퓨터 프로그램을 개발하였다. 하나는 자료수집 (data aquisition), 자료의 표시, 통계처리, 오차추정, 대기상태의 모니터링 등을 다루는 실시간(實時間, real time) 측광제어 프로그램이고, 다른 하나는 하룻밤 관측의 도중 또는 관측 종료 직후에 수집된 자료 전체를 입력 파일로 만들어 주면 대기소광계수 결정과 표준계 변환 및 오차 추정을 해 주는 자료분석(資料分析, data reduction) 프로그램이다. 두 프로그램은 모두 임의의 다색측광계(多色測光系)에 대해서 입력 과일에 필터의 갯수, 색지 수의 정의 등 필요한 자료만 써주면 수행 가능하도록 일반화되어 있다.