103 citations · 871 across the 43 of their papers we have counts for
25 papers · 1 filter
Long-period radial velocity variations of nine M red giants: The detection of sub-stellar companions around HD 6860 and HD 112300
Byeong-Cheol Lee, Hee-Jin Do, Myeong-Gu Park +7
Context. Certain periodic variations of radial velocities (RV) of wobbling giants originate from exoplanets. Indeed, a number of exoplanets have been discovered around giant stars.…
Hybrid star HD 81817 accompanied by brown dwarf or substellar companion
Tae-Yang Bang, Byeong-Cheol Lee, V. Perdelwitz +4
HD 81817 is known as a hybrid star. Hybrid stars have both cool stellar wind properties and Ultraviolet (UV) or even X-ray emission features of highly ionized atoms in their spectr…
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…
Photospheric carbon, nitrogen, and oxygen abundances of A-type main-sequence stars
Yoichi Takeda, Satoshi Kawanomoto, Naoko Ohishi +4
Based on the spectrum fitting method applied to CI 5380, NI 7486, and OI 6156-8 lines, we determined the abundances of C, N, and O for 100 mostly A-type main-sequence stars (late B…
The Radial Velocity Variability of the K-giant Gamma Draconis: Stellar Variability Masquerading as a Planet
A. P. Hatzes, M. Endl, W. D. Cochran +9
We present precise stellar radial velocity measurements of Gamma Dra taken from 2003 to 2017. The data from 2003 to 2011 show coherent, long-lived variations with a period of 702 d…