• The Bulletin of The Korean Astronomical Society
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• v.9
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• pp.9.1-9.1
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• 1984

• Journal of The Korean Astronomical Society
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• v.54 no.3
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• pp.89-102
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• 2021

Even in an era where 8-meter class telescopes are common, small telescopes are considered very valuable research facilities since they are available for rapid follow-up or long term monitoring observations. To maximize the usefulness of small telescopes in Korea, we established the SomangNet, a network of 0.4-1.0 m class optical telescopes operated by Korean institutions, in 2020. Here, we give an overview of the project, describing the current participating telescopes, its scientific scope and operation mode, and the prospects for future activities. SomangNet currently includes 10 telescopes that are located in Australia, USA, and Chile as well as in Korea. The operation of many of these telescopes currently relies on operators, and we plan to upgrade them for remote or robotic operation. The latest SomangNet science projects include monitoring and follow-up observational studies of galaxies, supernovae, active galactic nuclei, symbiotic stars, solar system objects, neutrino/gravitational-wave sources, and exoplanets.

• Journal of Astronomy and Space Sciences
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• v.41 no.1
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• pp.1-15
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• 2024

The Korean heliospheric community, led by the Korea Astronomy and Space Science Institute (KASI), is currently assessing the viability of deploying a spacecraft at the Sun-Earth Lagrange Point L4 in collaboration with National Aeronautics and Space Administration (NASA). The aim of this mission is to utilize a combination of remote sensing and in situ instruments for comprehensive observations, complementing the capabilities of the L1 and L5 observatories. The paper outlines longterm scientific objectives, underscoring the significance of multi-point in-situ observations to better understand critical heliospheric phenomena. These include coronal mass ejections, magnetic flux ropes, heliospheric current sheets, kinetic waves and instabilities, suprathermal electrons and solar energetic particle events, as well as remote detection of solar radiation phenomena. Furthermore, the mission's significance in advancing space weather prediction and space radiation exposure assessment models through the integration of L4 observations is discussed. This article is concluded with an emphasis on the potential of L4 observations to propel advancements in heliospheric science.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.96.2-96.2
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• 2013

The solar images are taken by the CCD detectors of the Sun monitoring satellites. The solar images are constructed after removing the traces of cosmic rays on the raw CCD data files. Thus, while applying the method of removing the cosmic rays traces, we can estimate the cosmic rays flux by counting the number of traces. The cosmic ray flux in the steady state might be the sum of the solar and galactic cosmic rays. However, the abrupt change in the flux could be assumed to be originated from the Sun. Therefore, we can identify the solar origins of the sudden solar cosmic ray flux changes from the phenomena shown in the processed solar images taken by SOHO/EIT. As the results, the estimated cosmic ray flux in the steady state is the anti-correlated with sunspot numbers, which shows the minima in cosmic ray flux at the solar cycle maxima defined by the sunspot numbers. The profiles of estimated solar cosmic ray associated with the ground level enhancements have the significant increase in the cosmic ray flux with good correlation. Thus, the solar images are valuable data useful in estimating the solar cosmic ray long term and transient flux variations.

• Journal of The Korean Astronomical Society
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• v.32 no.1
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• pp.7-16
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• 1999

Open clusters are useful tools to investigate the structure and evolution of the Galactic disk. We have started a long-term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telescope of Bohyunsan Optical Astronomy Observatory in Korea. The primary goals of this project are (1) to make a catalog of UBVI photometry of open clusters, (2) to make an atlas of open clusters, and (3) to survey and monitor variable stars in open clusters. Here we describe this project and report the first results based on preliminary analysis of the data on four open clusters in the survey sample: Be 14, Cr 74, Biu 9, and NGC 2355. Isochrone fitting of the color-magnitude diagrams of the clusters shows that all of them are intermediate age to old (0.3-1.6 Gyrs) open clusters with moderate metallicity.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.79.2-79.2
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• 2012

SN 2011fe (also known as PTF 11kly) is a Type-1a supernova that appeared in M101, 2011 August. Being only 6.4 Mpc away, this supernova has been intensively observed by various facilities in the world. We monitored this supernova in UBVRI, grizY, and ZYJHK-bands using SNUO, LOAO, SOAO, CQUEAN/McDonald, UKIRT telescopes, and small telescopes in Korea and Mongolia. The monitoring observation is still ongoing, and the light curve has been accumulated over a year. We present the results of the long-term monitoring observation, together with a light-curve fitting result. We will also discuss our findings in terms of the usefulness of Type-Ia supernovae as a distance indicator.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.303-309
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• 2014

The Earth's outer radiation belt often suffers from drastic changes in the electron fluxes. Since the electrons can be a potential threat to satellites, efforts have long been made to model and predict electron flux variations. In this paper, we describe a prediction model for the outer belt electrons that we have recently developed at Chungbuk National University. The model is based on a one-dimensional radial diffusion equation with observationally determined specifications of a few major ingredients in the following way. First, the boundary condition of the outer edge of the outer belt is specified by empirical functions that we determine using the THEMIS satellite observations of energetic electrons near the boundary. Second, the plasmapause locations are specified by empirical functions that we determine using the electron density data of THEMIS. Third, the model incorporates the local acceleration effect by chorus waves into the one-dimensional radial diffusion equation. We determine this chorus acceleration effect by first obtaining an empirical formula of chorus intensity as a function of drift shell parameter $L^*$, incorporating it as a source term in the one-dimensional diffusion equation, and lastly calibrating the term to best agree with observations of a certain interval. We present a comparison of the model run results with and without the chorus acceleration effect, demonstrating that the chorus effect has been incorporated into the model to a reasonable degree.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.2
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• pp.148-157
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• 2012

The purpose of this study was to analyze the terms of astronomy area used in six convergence science textbooks by 2009 curriculum revision. The results of this study were following; the first, the contents about astronomy occupied about 18.6% account of science contents. There were the terms which all textbooks used, but some terms were not used other text book, and the others were used in only one textbook. And the second, there were some terms of having certain concept which had described differently. It was suggested that it was necessary to the effort to prevent to descript same meaning terms differently and to make guideline for the depth and width of the terms.

• Molecules and Cells
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• v.39 no.12
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• pp.841-846
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• 2016

Local protein synthesis mediates precise spatio-temporal regulation of gene expression for neuronal functions such as long-term plasticity, axon guidance and regeneration. To reveal the underlying mechanisms of local translation, it is crucial to understand mRNA transport, localization and translation in live neurons. Among various techniques for mRNA analysis, fluorescence microscopy has been widely used as the most direct method to study localization of mRNA. Live-cell imaging of single RNA molecules is particularly advantageous to dissect the highly heterogeneous and dynamic nature of messenger ribonucleoprotein (mRNP) complexes in neurons. Here, we review recent advances in the study of mRNA localization and translation in live neurons using novel techniques for single-RNA imaging.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.84.1-84.1
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• 2011

In this study, we intend to inquire of how the temporal variation and spatial distribution of magnetic helicity injection in a CME-producing solar active region are related to the CME occurrence. We therefore investigate long-term (a few days) variation of magnetic helicity injection in the active region NOAA 9236 which produced multiple CME events. As a result, it is found that a noticeable increase in helicity of negative sign was first made for the first ~1.5 days and then 6 CMEs occurred while the relatively more injection of oppositely signed (positive) helicity was taking place for the next ~2 days. Afterwards, 2 CMEs in the region occurred while a more negative helicity is being injected again compared to a positive helicity. In addition, from helicity flux density maps, we found that the CMEs originated from this active region seem to be involved with the interaction of two magnetic field systems characterized by opposite signs of helicity.