• 천문학논총
• /
• 제34권3호
• /
• pp.41-48
• /
• 2019

We compared and analyzed the astronomy terms currently used by astronomers in the two Koreas to promote inter-Korean astronomy cooperation. We analyzed a total of 2716 pairs of terms common in both Koreas glossaries, using the astronomical terminology contained in the South Korean source, the 'Terminology of Astronomy', and the North Korean source, 'Mirror 2.0'. For each pair of terms, their morphological features and meanings were compared. We categorized into 11 groups for comparison of astronomical terms. We found that most of the terms are used similarly in the two Koreas. About 47% of the total is similar in form. Although terms are different, meanings communicate about 37% of the total. As a result, similar terms used by the two Koreas correspond to about 85% of the total. However, 15% of terms are difficult to understand because they have different forms or meanings such as diffraction (회절/에돌이), flare (플레어/요반) etc. Further research on terms that are used differently by the two Koreas, and the conversion of appropriate terms through mutual understanding should be made in the future.

• 천문학회보
• /
• 제43권2호
• /
• pp.43.4-43.4
• /
• 2018

As of July 24th 208, Korea Astronomy and Space Science Institute (KASI) has entered into a formal partnership with the Gemini Observatory. The Gemini Observatory has been operated by Association of Universities for Research in Astronomy (AURA) on behalf of the International Partnership that includes Argentina, Brazil, Canada, Chile, United States, and Korea as the new partner country. Effective from the 209A Call for Proposals (CfP), any researchers affiliated with Korean institutes are eligible to apply for various observing opportunities in both hemispheres covered by Gemini North in Hawaii and by Gemini South in Chile. We are going to share the importance and long-term perspectives of the KASI-Gemini Partnership in the context of the next decade of Korean optical astronomy researches.

• 천문학회보
• /
• 제22권
• /
• pp.6-6
• /
• 1997

• 천문학회보
• /
• 제35권2호
• /
• pp.50.1-50.1
• /
• 2010

The New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO) is the recently constructed world largest 1.6 m optical solar telescope on the ground. We took an observation of the north polar limb in H-alpha line center wavelength on 2009 August 26 with the instrument at Nasmyth focus of the NST and found a remarkable small-scale H-alpha eruption from 18:20 UT and 18:45 UT. The eruption occurred with a relatively slow speed of about 10 km/s in early stage and a slight acceleration up to 20-30 km/s in later stage. We also found that the eruption shows a deflection along the pre-existing magnetic field as well as several interesting features such as bifurcation, rotation, horizontal oscillation, and direction and thickness change of its structure during the eruption. In this talk, we will report the observational properties of the small-scale eruption observed by the NST and discuss their implication on magnetic reconnection.

• 천문학회보
• /
• 제35권2호
• /
• pp.52.1-52.1
• /
• 2010

The Japanese infrared (IR) space mission AKARI monitored the brightness in the fields very close to the north ecliptic pole (NEP) with nine wavebands in Infrared Camera (IRC), which cover the wavelength range from 2 to $24{\mu}m$. We reduced the NEP monitor observations and examined the smoothness of the sky background brightness. Our analysis shows that the background brightness is smooth over a frame of about $10'\times10'$ within about 0.1% deviation in mid-IR. Because the zodiacal light (ZL) and emission (ZE) dominate the diffuse sky brightness in the near- and mid-IR wavelengths, the background brightness varies with season through a year. We tried sinusoidal fittings to the observed NEP background brightness. The fitting analysis shows that the sine function is successful in describing the seasonal variation of the ZL and ZE within 2% deviations from the observed brightness, especially for the 15, 18, and $24{\mu}m$ bands, within 0.3%. These results will provide limits and caveats for the studies of the cosmic infrared background radiation.

• 천문학회보
• /
• 제37권2호
• /
• pp.90.1-90.1
• /
• 2012

Galaxy clusters, the largest gravitationally bound system, are important means to place constraints on cosmological model and to study the evolution and the formation of galaxies and their large scale distribution. We will report results from our study of galaxy clusters in the European Large Area ISO Survey North1/North2(ELAIS-N1/N2) fields, covering a total of 10.8 $deg^2$. We combine multiple wavelength data from IMS survey, UKIRT Infrared Deep Survey-Deep Extragalactic Survey (UKIDSS-DXS, JK bands), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE, Optical-Infrared bands), and CFHT (u,g,r,i,z bands.) The photometric redshifts are derived from these datasets and are used to search for high redshift galaxy clusters at 0.8 < z < 1.5.

• Journal of Astronomy and Space Sciences
• /
• 제36권4호
• /
• pp.225-234
• /
• 2019

We explore the associations between the total sunspot area, solar north-south asymmetry, and Southern Oscillation Index and the physical characteristics of clouds by calculating normalized cross-correlations, motivated by the idea that the galactic cosmic ray influx modulated by solar activity may cause changes in cloud coverage, and in turn the Earth's climate. Unlike previous studies based on the relative difference, we have employed cloud data as a whole time-series without detrending. We found that the coverage of high-level and low-level cloud is at a maximum when the solar north-south asymmetry is close to the minimum, and one or two years after the solar north-south asymmetry is at a maximum, respectively. The global surface air temperature is at a maximum five years after the solar north-south asymmetry is at a maximum, and the optical depth is at a minimum when the solar north-south asymmetry is at a maximum. We also found that during the descending period of solar activity, the coverage of low-level cloud is at a maximum, and global surface air temperature and cloud optical depth are at a minimum, and that the total column water vapor is at a maximum one or two years after the solar maximum.

• Journal of Astronomy and Space Sciences
• /
• 제36권3호
• /
• pp.149-157
• /
• 2019

In this study, we investigate the associations between the solar variability and teleconnection indices, which influence atmospheric circulation and subsequently, the spatial distribution of the global pressure system. A study of the link between the Sun and a large-scale mode of climate variability, which may indirectly affect the Earth's climate and weather, is crucial because the feedbacks of solar variability to an autogenic or internal process should be considered with due care. We have calculated the normalized cross-correlations of the total sunspot area, the total sunspot number, and the solar North-South asymmetry with teleconnection indices. We have found that the Southern Oscillation Index (SOI) index is anti-correlated with both solar activity and the solar North-South asymmetry, with a ~3-year lag. This finding not only agrees with the fact that El $Ni{\tilde{n}}o$ episodes are likely to occur around the solar maximum, but also explains why tropical cyclones occurring in the solar maximum periods and in El $Ni{\tilde{n}}o$ periods appear similar. Conversely, other teleconnection indices, such as the Arctic Oscillation (AO) index, the Antarctic Oscillation (AAO) index, and the Pacific-North American (PNA) index, are weakly or only slightly correlated with solar activity, which emphasizes that response of terrestrial climate and weather to solar variability are local in space. It is also found that correlations between teleconnection indices and solar activity are as good as correlations resulting from the teleconnection indices themselves.

• Journal of Astronomy and Space Sciences
• /
• 제24권4호
• /
• pp.261-268
• /
• 2007

We have studied the temporal variation in the North-South asymmetry of the sunspot area during the period from 1874 to 2007. Though the 9-year periodicity is commonly reported, shorter periodicities is still under study. We employ the cepstrum analysis method to analyze the noisy power spectrum of the North-South asymmetry. We demonstrate that the cleaned power spectrum shows reduction of the spurious back-ground noise level. Some of short period peaks in the power spectrum disappear after deconvolution. It should be, however, pointed out that power spectrum might look less noisy because of a filtering process during deconvolution. We conclude by pointing out that a more sophisticate filtering algorithm is required to produce a precise and reliable periodicity estimate.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2007년도 한국우주과학회보 제16권2호
• /
• pp.73-73
• /
• 2007