• Journal of The Korean Astronomical Society
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• v.33 no.3
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• pp.143-149
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• 2000

We present the results of near-IR band (JHK) photometric study for the old open cluster To 2. Combined with existing optical data, our IR photometry is used to derive the reddening E(B- V)=0.24$\pm$0.12 and the distance (m-M)o=14.6$\pm$0.42. Comparison with theoretical isochrones suggests the age and metallicity of To 2 are log t$\~$9.3 and [Fe/H]$\~$-0.3, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.90.1-90.1
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.117.1-117.1
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• 2014

"Circumstellar disks, exoplanets and the solar system" is the one of ALMA proposal categories, which is closely related to the one of the fundamental questions in astrophysics, " when, where, and how planets form". I will review the Cycle-0/1 observational results of this topic, which had only 16/32 antennas and the maximum angular resolutions of 0.45/0.16 arcsec at 345GHz at that time. Eventually, ALMA equipped with 66 antennas and 0.01 arcsec angular resolution will allow us to study details of the circumstellar disks with the 1AU resolution at the distance of 100pc.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.84.2-84.2
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• 2014

We report the discovery of a new Milky Way globular cluster (GC) candidate in the Galactic plane. We found this object during our WISE survey of star clusters in the Milky Way. We derived physical parameters of this object using the 2MASS JHK photometry. The color-magnitude diagram of the resolved stars shows a well-developed red giant branch (RGB). We derived its reddening, distance and metallicity. These results indicate that it is probably an old globular cluster, located behind the Galactic disk.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.145-146
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• 1996

We have estimated a metal abundance of [Fe/H]= -0.04 $\pm$ 0.05 dex, a reddening of E(B- V)= 0.28 mag, an age of 1.1 $\pm$ 0.1 Gyr, and a distance of 2.5 $\pm$ 0.2 kpc for NGC 1245 using the Washington filter system.

• Journal of The Korean Astronomical Society
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• v.38 no.4
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• pp.423-428
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• 2005

The main physical parameters; the cluster center, distance, radius, age, reddening, and visual absorbtion; have been re-estimated and improved for the open cluster NGC 7086. The metal abundance, galactic distances, membership richness, luminosity function, mass function, and the total mass of NGC 7086 have been examined for the first time here using Monet et al. (2003) catalog.

• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.127-140
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• 1998

With a large format near-infrared camera at the 2.2-m telescope on Mauna Kea Observatory, we performed J K near-infrared observations for the metal rich globular cluster NGC6712. This cluster lies near the galactic plane and therefore suffers heavy reddening. We present the near-infrared color-magnitude diagram and also derive the metallicity ([Fe/H] ${\~}-0.96{\pm}0.27$) as well as its distance modulus ((m - M) ${\~}13.42{\pm}0.12$).

• Journal of The Korean Astronomical Society
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• v.38 no.3
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• pp.357-363
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• 2005

A deep stellar analysis is introduced for the poorly studied open cluster NGC 2509. The Near-IR database of the digital Two Micron All Sky Survey (2MASS) has been used to re-estimate and refine the fundamental parameters of the cluster, i.e. age, reddening, distance, and diameter. As well as, luminosity function, mass function, total mass, relaxation time, and mass segregation of NGC 2509 have been estimated here for the first time..

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.233-233
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• 2012

I review the dependence of galaxy properties on environmental parameters such as the local density, nearest neighbor distance and morphology. We find that a galaxy with an early- or late-type nearest companion within its virial radius tends to be an early or late type, respectively. The morphology of galaxies located in high density regions tends to be the same as that of the ones in low density regions if their luminosity and the nearest neighbor environment are the same. This strongly supports that galaxy morphology and luminosity evolution have been driven mainly by galaxy-galaxy interactions, and the background density affected morphology and luminosity only through the frequency of interactions.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.30.4-31
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• 2021

We will present a scenario of the presence of a second AGN in a nearby Seyfert galaxy, NGC 1068. Using VLT/MUSE IFU data, we investigated the complex kinematics of ionized gas in the central region of NGC 1068. Interestingly, at a distance of 180 pc to the northeast from the nucleus of NGC 1068, we detected a kinematical signature of the launching point of AGN gas outflows, which suggests that there would be a second AGN. We will also discuss another supporting evidence of the second AGN based on previous spectropolarimetric results.