• Title/Summary/Keyword: eclipsing

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NEW VARIABLE STARS IN THE REGION OF THE OPEN CLUSTER M35 (NGC 2168) (산개성단 M35(NGC 2168) 영역의 새로운 변광성)

  • Jeon, Young-Beom;Lee, Hye-Ran
    • Publications of The Korean Astronomical Society
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    • v.25 no.4
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    • pp.167-176
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    • 2010
  • In the region of the intermediate open cluster M35 (NGC 2168), the time-series of V CCD images was taken for 12 nights from December 18, 2007 to September 25, 2010. From this observation, we detected 22 variable stars including 15 new ones. They are 6 $\delta$ Scuti, a Cepheid, an RR Lyrae, 9 eclipsing binaries and 5 semi-long periodic and/or slow irregular type variable stars. For the V photometry of the $\delta$2 Scuti stars, the multi-frequency analysis was performed using the Discrete Fourier Transform and the linear least-square fitting.

MO Studies of Configurations and Conformations (IX). Molecular Structure of Sulfamoyl Chlorides

  • Ik-choon Lee;Byung-Choon Lee
    • Bulletin of the Korean Chemical Society
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    • v.1 no.2
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    • pp.57-62
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    • 1980
  • Semi-empirical MO calculations were performed to investigate stereochemical properties of sulfamoyl chlorides; $R_2NSO_2Cl$ Where R = H or $CH_3$. It was found that for all the molecules considered the most preferred conformation was the form in which $n_N-{\sigma}^*_{SIC}$ conjugative interaction is a maximum and the least favored conformation was the form in which steric repulsion is large due to eclipsing of Cl and R. In case of the molecule with no symmetry i.e., $CH_2NHSO_2Cl$, the stability was also dependent upon nonbonded interactions between the eclipsing groups.

The Molecular Structure and Conformational Stability of Cyclobutylmethyl Ketone by MM2

  • Lee, Mu-Sang;Jung, Young-Mee
    • Bulletin of the Korean Chemical Society
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    • v.10 no.3
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    • pp.247-250
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    • 1989
  • The molecular structure of cyclobutylmethyl ketone (c-$C_4H_7COCH_3$) has been investigated by molecular mechanics II (MM2). For the monosubstituted cyclobutane there are two possible ring conformations, the equatorial and axial form, but for the cyclobutylmethyl ketone the equatorial form is predominant conformation. For the $COCH_3$ moiety there are two stable orientations which are the equatorial-gauche and the equatorial-trans form. The equatorial-gauche form where the C = O bond is nearly eclipsing (torsional angle ${\angle}C4-C3-C2-O10=14.5^{\circ}$) one of the ${\alpha}$C-C bonds of the four-membered ring was preferred conformer with steric energy of 13.37 kcal/mol. The equatorial-trans form where the C = O bond is nearly eclipsing (${\angle}C4-C3-C2-O10=145.0^{\circ}$) the ${\alpha}$ C-H bond of the four-membered ring was less stable conformer with steric energy of 15.40 kcal/mol.

Two-Color Photometry of V448 Monocerotis

  • Nha, Il-Seong
    • Journal of The Korean Astronomical Society
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    • v.7 no.1
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    • pp.16-18
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    • 1974
  • Photolectric observations with B and V filters of the eclipsing binary system V448 Monocerotis are presented. The light curves, which cover 30% of the light cycle, show the variability of this system.

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SPECTROSCOPIC STUDY OF LONG PERIOD ECLIPSIING BINARY 32 CYGNI

  • Chun, Mun-Suk
    • Journal of Astronomy and Space Sciences
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    • v.9 no.2
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    • pp.143-153
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    • 1992
  • Spectra of the $\zeta$ Aurigae type eclipsing binary system 32 Cygni were taken at the Asiago Observatory. Using the Gaussian fitting method we can estimate the radial velocity and equivalent widths of some metalic lines.

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