• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.77.3-77.3
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• 2017

We present some results of the spectral analysis for Type Ia supernova SN 2011fe in M101, which was discovered by the Palomar Transient Factory on August 24 2011 UT. We performed spectroscopic observations for SN 2011fe at Bohyunsan Optical Astronomy Observatory with the high resolution echelle spectrograph BOES attached to 1.8-m reflector. Spectra of 18 epochs are obtained from September 6 2011 to April 1 2012 UT. Spectral feature variations for several significant lines and explosion mechanism will be discussed.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.117-124
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• 2005

We plan to install the polarimetric optics in the AGU(acqusition and guiding unit) of the 1.8 m telescope at the BOAO(Bohyunsan Optical Astronomy Observatory). With this, the spectropolarimetric observations with the resolution of 45,000 and 60,000 in 4,000 to $8,000{\AA}$ ange could be done by the BOES(BOao Echelle Spectrograph). If we use the precision radial velocity measurement capability of the BOES, the accuracy of the magnetic field intensity measurements with this new BOES stokesmeter will be much increased. We present here the design concept of the BOES stokesmeter. Some details on the optics, mechanical parts, fiber parts and the lab test procedures of this stokesmeter are explained.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.29-35
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• 2005

Time-series observations were carried out using a 155mm refractor and a $2k{\times}3k$ CCD camera at Bohyunsan Optical Astronomy Observatory. We found 38 new variable stars in the $2.3^{\circ}{\times}2.4^{\circ}$ region around the Cepheid variable TU Cas: 22 eclipsing binary stars, 11 ${\delta}$ Scuti type stars and an RR Lyrae star, and 4 unclassified variables.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.21-25
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• 2004

We analyzed the high resolution H,6 line spectra of CH Cygni obtained at the Bohyunsan Astronomical Observatory (BOAO) on April 2004. The temporal changes in the $H\beta$ line profiles are reported. We obtained the equivalent widths of the Gaussian components. Using this we estimated the length of the gaseous nebula which emits the $H\beta$ line and the mass loss rate from the star.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.33-37
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• 2004

Through time-series CCD photometry using a 130mm refractor of Busan Science Academy, we found a new $\delta$ Scuti type variable star, esc 03665-00576. We performed following observations using a 1.8m telescope of Bohyunsan Optical Astronomy Observatory. Three frequencies have been derived by multiple-frequency analysis, which are 10.968, 7.156 and 15.182cycle $day^{-1}$, respectively. V-amplitude of esc 03665-00576 is ${\Delta}V$= 0.04.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.39-46
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• 2004

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 $CH_4$ absorption lines of the Kuiper bands, and find unidentified lines near $7500{\AA}$.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.71-76
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• 2004

We have developed a tool for measuring optical aberrations of telescope. We adopt curvature sensing technique and use the least square method for finding the amplitudes of the Zernike polynomials. This tool runs under the PC Linux system and the PC windows system with Linux emulators such as Cygwin. The program for UNIX system is used for optical alignment of 1.8M optical telescope at the Bohyunsan Optical Astronomical Observatory (BOAO) and the PC based program is used for the Korea Astronomy Observatory (KAO) wide field telescope (named NEOPAT-3). Our tool is found to be efficient for precise measurement of the optical aberrations of telescopes.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.55-63
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• 2004

Observation environment of the Bohyunsan Optical Astronomy Observatory(BOAO) has been examined using various statistical data including real observation times versus allocated times and seeing statistics. The data have been collected from the observation logs of the 1.8m telescope in the period 1998 - 2004. New criteria have been set up to calculate a more realistic observation efficiency of the observatory. The new statistical analysis based on the new criteria gives the overall observation efficiency of BOAO as $38.6\%$, that is equivalent to 115.8 observable nights out of 300 allocatable nights. The seeing statistics shows that the mean seeing measured at the focal images is 2".3. The present study of the observation environment of BOAO suggests that differential photometry and spectroscopy should be preferred modes of observation to maximize the productivity of BOAO.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.58.3-59
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• 2018

We present the results of high resolution spectral analysis for Type Ia supernova SN 2014J in M82, which was discovered on 21 January 2014 UT. We performed spectroscopic observations for SN 2014J in its early phase at Bohyunsan Optical Astronomy Observatory with the high resolution echelle spectrograph BOES attached to 1.8-m reflector. Spectra of 26 epochs in 6 nights were obtained from 22 January 2014 to 23 February 2014 UT. Spectral feature variations for several significant lines including Si II and Ca II lines will be shown and discussed.

• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.141-160
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• 1998

We have conducted BV RI CCD surface photometry of three spiral galaxies ESO 598-G009, NGC 1515 and NGC 7456. In order to understand the morphological properties and luminosity distribution characteristics for each galaxy, we derived isophotal map, position angle profile, ellipticity profile, luminosity profile, color profile and color contour map. ESO 598-G009, which has a bright bulge component and a ring, shows a trace of gravitational interaction. NGC 1515 is a spiral galaxy with a bar and dust lane. NGC 7456 shows typical characteristics of a late type spiral galaxy.