Publications (27)
Formation process of young stellar population in Messier 16 from a kinematic perspective
Beomdu Lim, Hyeong-Sik Yun, Hyun-Jeong Kim +4
We present a kinematic study of young stars in Messier 16 (M16) using the Gaia Data Release 3 and high-resolution spectra. A total of 345 stars are selected as genuine members usin…
KIC 4739791: A New R CMa-type Eclipsing Binary with a Pulsating Component
Jae Woo Lee, Seung-Lee Kim, Kyeongsoo Hong +3
The {\it Kepler} light curve of KIC 4739791 exhibits partial eclipses, inverse O'Connell effect, and multiperiodic pulsations. Including a starspot on either of the binary componen…
SPECtrophotometer for TRansmission spectroscopy of exoplanets (SPECTR)
Yeon-Ho Choi, Myeong-Gu Park, Kang-Min Kim +9
The SPECtrophotometer for TRansmission spectroscopy of exoplanets (SPECTR) is a new low-resolution optical (3800 Ã - 6850 Ã ) spectrophotometer installed at the Bohyunsan Optical A…
A search for exoplanets around north circumpolar stars. VII. Detection of planetary companion orbiting the largest host star HD 18438
Byeong-Cheol Lee, Jae-Rim Koo, Gwanghui Jeong +3
We have been conducting a exoplanet search survey using Bohyunsan Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in…
The Pre-He White Dwarfs in Eclipsing Binaries. I. WASP 0131+28
Jae Woo Lee, Jae-Rim Koo, Kyeongsoo Hong +1
We report the first light curves and high-resolution spectra of the post-mass transfer binary star WASP 0131+28 to study the absolute properties of extremely low-mass white dw…
Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. II. Young Clusters in NGC 1313
Jae-Rim Koo, Hyun-Jeong Kim, Beomdu Lim
We present a spectroscopic study of young stellar clusters in the barred spiral galaxy NGC 1313. Integrated light spectra of 11 clusters, obtained using the GMOS-S instrument on th…
The Eclipsing System V404 Lyr: Light-Travel Times and Gamma Doradus Pulsations
Jae Woo Lee, Seung-Lee Kim, Kyeongsoo Hong +2
We present the physical properties of V404 Lyr exhibiting eclipse timing variations and multiperiodic pulsations from all historical data including the Kepler observations. Detaile…
Origin and Status of Low-Mass Candidate Hypervelocity Stars
Bum-Suk Yeom, Young Sun Lee, Jae-Rim Koo +2
We present an analysis of the chemical abundances and kinematics of six low-mass dwarf stars, previously claimed to be candidate hypervelocity stars (HVSs). We obtained moderate-re…
A Search for exoplanets around northern circumpolar stars VIII. filter out a planet cycle from the multi-period radial velocity variations in M giant HD 3638
Byeong-Cheol Lee, Gwanghui Jeong, Jae-Rim Koo +6
This paper is written as a follow-up observations to reinterpret the radial velocity (RV) of HD 36384, where the existence of planetary systems is known to be ambiguous. In giants,…
The Varying Light Curve and Timings of the Ultra-short Period Contact Binary KIC 9532219
Jae Woo Lee, Kyeongsoo Hong, Jae-Rim Koo +1
KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of 0.1981549 d that is below the short-period limit (0.22 d) of the period distribution for contact binari…
Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies I. Young Massive Clusters in the Antennae galaxies
Jae-Rim Koo, Hyun-Jeong Kim, Beomdu Lim
The stellar initial mass function (IMF) is a key parameter to understand the star formation process and the integrated properties of stellar populations in remote galaxies. We pres…
Determination of Sodium Abundance Ratio from Low-Resolution Stellar Spectra and Its Applications
Jae-Rim Koo, Young Sun Lee, Hye-Jin Park +2
We present a method to determine sodium-abundance ratios ([Na/Fe]) using the Na I D doublet lines in low-resolution ( 2000) stellar spectra. As stellar Na I D lines are ble…
Absolute dimensions and evolutionary status of the semi-detached Algol W Ursae Minoris
Jang-Ho Park, Kyeongsoo Hong, Jae-Rim Koo +2
Double-lined eclipsing binaries allow accurate and direct determination of fundamental parameters such as mass and radius for each component, and they provide important constraints…
KIC 11401845: An Eclipsing Binary with Multiperiodic Pulsations and Light Travel Time
Jae Woo Lee, Kyeongsoo Hong, Seung-Lee Kim +1
We report the photometry of KIC 11401845 displaying multiperiodic pulsations, superimposed on binary effects. Light-curve synthesis represents that the binary star i…
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.…
Detection of planets in extremely weak central perturbation microlensing events via next-generation ground-based surveys
Sun-Ju Chung, Chung-Uk Lee, Jae-Rim Koo
Even though the recently discovered high-magnification event MOA-2010-BLG-311 had complete coverage over the peak, confident planet detection did not happen due to extremely weak c…
A Search for Exoplanets around Northern Circumpolar Stars X. The origin of radial velocity variations in the evolved star HD 216595
Sang-Hee Kim, Byeong-Cheol Lee, Shenghong Gu +9
Detecting planetary companions around evolved stars, particularly asymptotic giant branch (AGB) stars, is challenging due to intrinsic stellar variability such as surface convectio…
Time-series spectroscopy of the pulsating eclipsing binary XX Cephei
Jae-Rim Koo, Jae Woo Lee, Kyeongsoo Hong +2
Oscillating Algol-type eclipsing binaries (oEA) are very interesting objects that have three observational features of eclipse, pulsation, and mass transfer. Direct measurement of…
Search for Extremely Metal-Poor Stars with GEMINI-N/GRACES I. Chemical-Abundance Analysis
Miji Jeong, Young Sun Lee, Timothy C. Beers +5
We present stellar parameters and abundances of 13 elements for 18 very metal-poor (VMP; [Fe/H] -2.0) stars, selected as extremely metal-poor (EMP; [Fe/H] -3.0) candidates…
Absolute Properties of the Eclipsing Dor Star V404 Lyrae
Jae Woo Lee, Kyeongsoo Hong, Jae-Rim Koo +1
We present the first high-resolution spectra for the eclipsing binary V404 Lyr showing Dor pulsations, which we use to study its absolute properties. By fitting models to the…
The Kepler Eclipsing Binary V2281 Cygni with Twin Stars
Jae-Rim Koo, Jae Woo Lee, Kyeongsoo Hong
We present the physical properties of the eclipsing binary V2281 Cyg, which shows a light-time effect due to a supposed tertiary component from its eclipse timing variation accordi…
Absolute Properties of the Pulsating Post-mass Transfer Eclipsing Binary OO Draconis
Jae Woo Lee, Kyeongsoo Hong, Jae-Rim Koo +1
OO Dra is a short-period Algol system with a Sct-like pulsator. We obtained time-series spectra between 2016 February and May to derive the fundamental parameters of the binar…
Evidence For Multiple Accretion Events in the -Sausage/Enceladus Structures
Young Kwang Kim, Young Sun Lee, Timothy C. Beers +1
We present evidence that multiple accretion events are required to explain the origin of the -Sausage and Enceladus (GSE) structures, based on an analysis of dynamical proper…
Physical Nature of the Eclipsing δ Scuti Star AO Serpentis
Jang-Ho Park, Jae Woo Lee, Kyeongsoo Hong +2
We present the absolute properties of the eclipsing binary AO Ser with a pulsating component from our photometric and high-resolution spectroscopic observations, which were pe…
KIC 6220497: A New Algol-type Eclipsing Binary with Multiperiodic Pulsations
Jae Woo Lee, Kyeongsoo Hong, Seung-Lee Kim +1
We present both binarity and pulsation of KIC 6220497 from the {\it Kepler} observations. The light curve synthesis shows that the eclipsing system is a semi-detached Algol with pa…
1SWASP J093010.78+533859.5: A Possible Hierarchical Quintuple System
Jae-Rim Koo, Jae Woo Lee, Byeong-Cheol Lee +5
We present the observational results of this kind of rare object 1SWASP J093010.78+533859.5, for which the doubly eclips- ing feature had been detected previously from the SuperWAS…
Physical Properties of the Transiting Planetary System TrES-3
Jae Woo Lee, Jae-Hyuck Youn, Seung-Lee Kim +2
We present four new transits of the planetary system TrES-3 observed between 2009 May and 2010 June. Among these, the third transit by itself indicates possible evidence for bright…