Master thesis Detection of Van Hoof effect in RR Lyrae stars from BOES observation Spectroscopy for RR Lyrae variables Target : TT Lyn, RR Leo, & SW Dra Instruments : 1.8m Telescope with BOES at Bohyunsan optical astronomy observatory High resolution echelle spectroscopy (R~60000) Result Van Hoof effect Phase lag between hydrogen line and metal lines Detection of the effect between … Hydrogen & metal lines Ca II & other metal lines Mg I & other metal lines (except TT Lyn) Hα & other Balmer lines

Post Master Spitzer IRAC observations of 30 Doradus complex in the LMC Archival data(AOR key 4379904) Reduction & Photometry MOPEX / APEX Result & Analysis Detection of young stellar objects(YSOs) YSOs are associated with the high velocity component of CO J=4-3 emitting clouds We discovered a cluster of YSOs which indicates a filamentary structure of star formation Publication Kim et al., 2007, ApJ, 669, 1003

Now I’m doing… Coursework for Ph.D. Extragalactic globular cluster study Photometry for the extragalactic GC system Target : NGC1399(Fornax cluster), M87(Virgo cluster) Instruments : 4m Blanco telescope with Mosaic II CCD at CTIO Multi band photometry U, B, V, & I for NGC1399 GCS M,T2, & DDO51 for M87 GCS Result & Analysis for NGC1399 By comparing the number ratio of blue and red GCs in various colors, we found that the color bimodality could not be interpreted as two distinct populations. We verified that YEPS model can reproduce the variation well. Our observational study supports the hypothesis of YYL06 on the origin of color bimodality.