Publications (35)
A search for kilogauss magnetic fields in white dwarfs and hot subdwarf stars
G. Valyavin, S. Bagnulo, S. Fabrika +4
We present new results of a survey for weak magnetic fields among DA white dwarfs with inclusion of some brighter hot subdwarf stars. We have detected variable circular polarizatio…
Lithium, Sodium, and Potassium Abundances in Sharp-Lined A-Type Stars
Yoichi Takeda, Dong-Il Kang, Inwoo Han +4
The abundances of alkali elements (Li, Na, and K) were determined from the Li I 6708, Na I 5682/5688, and K I 7699 lines by taking into account the non-LTE effect for 24 sharp-line…
Do Hertzsprung-Gap Stars Show Any Chemical Anomaly?
Yoichi Takeda, Gwanghui Jeong, Inwoo Han
With an aim to investigate how the surface abundances of intermediate-mass stars off the main sequence (evolving toward the red-giant stage) are affected by the evolution-induced e…
Compositional differences between the component stars of eclipsing close binary systems showing chemical peculiarities
Yoichi Takeda, Inwoo Han, Dong-Il Kang +2
A spectroscopic study was carried out on the surface chemical abundances of CNO and several heavier elements in the primary and secondary components of 5 eclipsing close binaries a…
Magnetic field and radial velocities of the star Chi Draconis A
Byeong-Cheol Lee, D. Gadelshin, Inwoo Han +13
We present high-resolution spectropolarimetric observations of the spectroscopic binary Chi Dra. Spectral lines in the spectrum of the main component Chi Dra A show variable Zeeman…
Search for Exoplanets around Northern Circumpolar Stars- II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742
Byeong-Cheol Lee, Gwanghui Jeong, Myeong-Gu Park +8
We present the detection of long-period RV variations in HD 36384, HD 52030, and HD 208742 by using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES)…