• 대한화학회지
• /
• 제18권1호
• /
• pp.47-49
• /
• 1974

감광트랜지스터 끝에 렌즈를 부착시켜 지향성을 충분히 좋게 한 것을 유리관 끝에 접착 밀봉하여 광도 검지기를 만들었다. 적정용액속에 이 감지기를 수직으로 담거 세우고, 밑에서 빛을 쪼여 올리면서 적정하는 방법을 발전시켜, 밝은 실험실에서 흡광광도 적정을 실시할 수 있게 하였다.

• Journal of Astronomy and Space Sciences
• /
• 제27권2호
• /
• pp.69-74
• /
• 2010

We present new BVR CCD photometric light curves for the close binary star V445 Cep. A new photometric solution and absolute physical dimensions of the system were derived by applying the Wilson-Devinney program to our observed light curves and radial velocity curves published by Pych et al. The evolutional status of V445 Cep was found to coincide with those of the general low mass ratio contact binary systems.

• 대한임베디드공학회논문지
• /
• 제8권2호
• /
• pp.111-119
• /
• 2013

This paper proposes one method on photometric stereo calibration using the constraint on light source directions in which the light sources have the unknown tilt and slant angles but the slant angles are the same. First, the constraint is analyzed based on the equation of linear ambiguity which leads to the conclusion that another constraint should be added to solve the calibration completely. Later, the combination of constraint on light source directions and the constraint that there exists at least six surface patches having known albedos is exploited to resolve the linear ambiguity up to an accurate and close-form solution. The effective performance of the proposed method is demonstrated through experiment results.

• Journal of Astronomy and Space Sciences
• /
• 제20권4호
• /
• pp.249-260
• /
• 2003

1998년 12월부터 1999년 5월까지 총 10일간 W UMa형 접촉쌍성 AH Cnc를 소백산천문대의 61cm 망원경과 PM512 CCD 카메라, 그리고 BVI 필터를 사용하여 CCD 측광을 수행하였다. 새롭게 얻은 BVI 광도곡선을 Wilson-Devinney 쌍성모델의 Mode 3(접촉형)으로 분석해서 측광해를 구하고 Roche 모형을 얻었다. 지금까지 발표된 모든 극심시각들과 이번 관측자료를 사용하여 얻은 (O-C)도를 분석해서 영년주기 증가율와 질량이동률을 계산하였다.

• Journal of Astronomy and Space Sciences
• /
• 제30권4호
• /
• pp.213-221
• /
• 2013

We present the first BVRI CCD photometric observations of V345 Cas made on 22 nights during the observing seasons in 2007-2008. Our light curves, resembling those of EB-type binary stars, are analyzed with the 2003 version of the Wilson-Devinney binary code. The photometric study shows that V345 Cas is a typical semi-detached binary system with the primary star being about ${\Delta}T$ = 2400 K hotter, two times more massive, but only 17% larger than the secondary star being filled with it's Roche-lobe. The orbit has a relatively large inclination of about $88^{\circ}$. A cool spot on the secondary component is modeled to explain a small light curve asymmetry. Absolute dimensions and related radiometric parameters of the eclipsing pair are calculated and their evolutionary states are discussed with the HR diagrams of mass-radius and temperature-luminosity. A period analysis of all available times of minima, including our measurements, indicates that the orbital period may vary in a cyclical way, unfortunately the secondary period for the variation can not be uniquely determined because of lack of present timing data.

• 천문학회지
• /
• 제29권spc1호
• /
• pp.241-242
• /
• 1996

The UBV observations of the close binary system CW Cephei were made from August 198:3 to December 1984 during 25 nights using the 61cm Boller and Chivens reflector at the Sobaeksan Astronomy Observatory. The new UBV light curves were analyzed with the recent Wilson-Devinney binary model. Our photometric solution for CW Cep were well consistent with those of Clausen &. Gimenez (1991). Using our photometric solution and Popper & Hill (1991) spectroscopic one, each absolute masses and radii of components for CW Cep were derived as 13.63 M$\bigodot$ and 5.83 R$\bigodot$ for the primary, and 12.18 M$\bigodot$ and 5.14 R$\bigodot$ for the secondary, respectively.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 1992년도 한국우주과학회보 제1권1호
• /
• pp.15-15
• /
• 1992

AQ Cassiopeiae (BD+61`0242, uv=10, Sp=B3+Bg) is a totally eclipsing binary system with the obital period of about 12 days. 71 was observed for 15 nights in 1985 with the1.8-m telescope at the DAO, employing a Reticon and a three-stage image tube attached to the spectrograph. And also, photometric observations of AQ Cas had been made inUBv for six years from 1982 to 1988 at Yonsei University Observatory(YUO). This work includes UBV observations obtained at YUO as a part of The Ten-Year Observing Program(1982-1992). Double lined radial, velocity curves and Ufv light curves of AQC as are constructed. The light curves and radial velocity curves show a strong evidence of circumstellar matter or mass stream. It is clear at the phases of just outside externaleclipse contacts, particularly at phase 0.8-0.9, shown in Figures 1 and 2. A solution by combining the radial velocity and photometric curves of the binary was obtained with the Wilson-Devinney Code. We found that the system is semi-detached with the coolcomponent filling its Roche lobe. The absolute dimensions of AQ Cas are calculated. The result shows that this system consists of two massive and subgiant stars.

• Journal of Astronomy and Space Sciences
• /
• 제14권2호
• /
• pp.225-232
• /
• 1997

A total of 1088 observations (272 in B, 272 in V, 272 in R, and 272 in I) were made from January to February in 1995 at Chungbuk National University observatory(CbNUO). We constructed BVRI light curves with our data. The photometric solution of these light curves was obtained by means of the Wilson-Devinney method. Our result was compared with those by previous investigators.

• Journal of Astronomy and Space Sciences
• /
• 제25권1호
• /
• pp.19-24
• /
• 2008

접촉 식쌍성 WZ Cep를 CCD 측광관측하여 BVR 광도곡선을 얻고, 5개의 극심 시각을 결정하였다. 새로운 3색의 광도곡선을 Wilson-Devinney 프로그램에 적용하여 측광학적인 해를 구하고, 광도곡선의 장주기 변화를 검증하였다. 우리 광도곡선의 형태는 전형적인 W UMa형의 대칭적인 것으로 나타나는 반면에 Hoffimann(1984)의 광도곡선은 매우 심한 O'Connell 효과를 보이는 비대칭으로 나타난다. WZ Cep의 대칭적인 광도곡선은 Djurasevic et al.(1998)의 광도곡선에서도 확인되었다.

• Journal of Astronomy and Space Sciences
• /
• 제26권1호
• /
• pp.1-8
• /
• 2009

질량비가 작은 접촉쌍성 FP Boo를 3색(B, V, R) CCD 측광관측하여 새로운 광도곡선을 얻었으며, Rucinski et al.(2005)의 시선속도곡선과 함께 Wilson-Devinney 프로그램에 적용하여 FP Boo의 새로운 측광학적 해와 절대물리량을 구하였다. FP Boo를 포함한 24개의 질량비가 작은 접촉쌍성의 H-R도로부터 FP Boo의 진화 상태도 일반적인 질량비가 작은 접촉쌍성의 진화 상태와 일치하는 위치에 놓이고 있음을 다시 확인하였다. 이번 관측을 통하여 얻은 우리의 광도곡선에서는 작지만 약간의 비대칭성을 보였다.