• 천문학회지
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• 제49권1호
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• pp.37-44
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• 2016

The Korea Microlensing Telescope Network (KMTNet) is a wide-field photometric system installed by the Korea Astronomy and Space Science Institute (KASI). Here, we present the overall technical specifications of the KMTNet observation system, test observation results, data transfer and image processing procedure, and finally, the KMTNet science programs. The system consists of three 1.6 m wide-field optical telescopes equipped with mosaic CCD cameras of 18k by 18k pixels. Each telescope provides a 2.0 by 2.0 square degree field of view. We have finished installing all three telescopes and cameras sequentially at the Cerro-Tololo Inter-American Observatory (CTIO) in Chile, the South African Astronomical Observatory (SAAO) in South Africa, and the Siding Spring Observatory (SSO) in Australia. This network of telescopes, which is spread over three different continents at a similar latitude of about -30 degrees, enables 24-hour continuous monitoring of targets observable in the Southern Hemisphere. The test observations showed good image quality that meets the seeing requirement of less than 1.0 arcsec in I-band. All of the observation data are transferred to the KMTNet data center at KASI via the international network communication and are processed with the KMTNet data pipeline. The primary scientific goal of the KMTNet is to discover numerous extrasolar planets toward the Galactic bulge by using the gravitational microlensing technique, especially earth-mass planets in the habitable zone. During the non-bulge season, the system is used for wide-field photometric survey science on supernovae, asteroids, and external galaxies.

• 천문학논총
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• 제30권2호
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• pp.683-685
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• 2015

A group of universities have come together with the aim of designing and developing Small Aperture Robotic Telescopes (SmART) for use by students to observe variable stars and transient follow-ups. The group is deliberating on the components of the robotic system; e.g. the telescope, the mount, the back-end camera, control software, and their integration keeping in mind the scientific objectives. The prototype might then be replicated by all the participating universities to provide round the clock observations from sites spread evenly in longitude across the globe. Progress made so far is reported in this paper.

• 천문학논총
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• 제38권2호
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• pp.75-89
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• 2023

Technosignature, previously known as SETI(search for extraterrestrial intelligence), is the scientific evidence of past or present extraterrestrial civilizations. Since NRAO's Project Ozma was performed in 1960, most of the noticeable technosignature searches have been done by radio telescopes, hoping to find strong and narrow bandwidth signals that cannot be explained by known natural processes. Recently, the Breakthrough Listen project has opened a new opportunity for technosignature by utilizing both optical telescopes, radio telescopes, and next-generation radio telescope arrays. In this review, mainly based on NASA Technosignatures Workshop (2018), we review the current trends of technosignature surveys, as well as other possible methods for detecting technosignature. Also, we suggest what the Korean community could contribute the technosignature research, including the new SETI project with Korea VLBI Network (KVN).

• 천문학회보
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• 제29권2호
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• pp.35.1-35.1
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• 2004

• 천문학논총
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• 제30권2호
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• pp.741-743
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• 2015

We have designed and built three cost effective observatories, in distinct models, which can house Schmidt-Cassegrain type small telescopes having aperture sizes up to 16 inches. Using the available small telescopes, we provided the people of Manipura State in the far north-east corner of India the opportunity to observe directly with their own eyes the rare, spectacular events of the solar eclipse of January 15, 2010, lunar eclipse of December 10, 2011 and the transit of Venus of June 6, 2012. Apart from sharing a platform with the public for astronomy education and popularization through public outreach programs such as workshops, seminars and night watch programs, we have also developed a laboratory infrastructure and gained expertise in observational techniques based on photoelectric photometry, CCD imaging, CCD photometry and spectroscopy. Our team has become a partner in the ongoing international 'Orion project' headquartered in Phoenix, Arizona, USA which will be producing high quality photometric and spectroscopic data for five stars in the Orion constellation, namely Betelgeuse (alpha Orionis), Rigel (beta Orionis), Mintaka (delta Orionis), Alnilam (epsilon Orionis) and Alnitak (zeta Orionis). In the present paper, the authors would like to give a detailed report of their activities for the growth of astronomy in the state of Manipur, India.

• 천문학논총
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• 제23권2호
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• pp.123-128
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• 2008

Productivity of the Giant Magellan Telescope is estimated based on the annual number of papers produced by the currently operating large telescopes such as the telescope at the ESO La Silla observatory, CFHT, AAT, the Magellan telescopes, ESO VLT, Japanese Subaru, the Gemini telescopes, and the Keck telescopes. We find that the amount of papers produced by a large telescope is roughly proportional to the diameter of its primary mirror. With this fact, we estimate the SCI-paper productivity of the Giant Magellan Telescope by extrapolating the productivity of the above-mentioned large telescopes. Moreover, according to the paper written in 2001 by Benn and Sanchez, the amount of highly-cited papers produced by a large telescope is roughly proportional to the light-gathering power of the telescope or the square of the diameter. Hence, we survey the productivity of Nature-class papers of the large telescopes and extrapolate the relationship to estimate the productivity of the Nature-class papers by using the Giant Magellan telescope of a filled aperture 21.4 meters in diameter. We expect that Korean astronomers will be able to produce annually 60 SCI-class papers and 20 Nature-class papers with high scientific impact by using the telescope-time corresponding to the 10% share of the Giant Magellan Telescope.

• 천문학논총
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• 제19권1호
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• pp.71-76
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• 2004

We have developed a tool for measuring optical aberrations of telescope. We adopt curvature sensing technique and use the least square method for finding the amplitudes of the Zernike polynomials. This tool runs under the PC Linux system and the PC windows system with Linux emulators such as Cygwin. The program for UNIX system is used for optical alignment of 1.8M optical telescope at the Bohyunsan Optical Astronomical Observatory (BOAO) and the PC based program is used for the Korea Astronomy Observatory (KAO) wide field telescope (named NEOPAT-3). Our tool is found to be efficient for precise measurement of the optical aberrations of telescopes.

• 천문학회보
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• 제41권1호
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• pp.58.1-58.1
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• 2016

K-GMT Science Program, operated by Center for Large Telescopes (CfLAT) in Korea Astronomy and Space Science Institute (KASI), aims to promote the scientific researches by providing the access to the observational facilities such as 4-8m class telescopes and specialized instruments. In 2016, we plan to make various instruments with MMT and Gemini Observatory as well as IGRINS with 2.7m HJS Telescope in McDonald Observatory available to Korean Astronomical Community. We will present the current status and future prospect as well as some early results made from the K-GMT Science Program in past years.

• 천문학회보
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• 제41권1호
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• pp.61.1-61.1
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• 2016

As a new way to explore the universe, astronomers are now performing time-domain astronomy by surveying the universe looking for new transient phenomena and taking movies of the universe with telescopes. Large-area, time-series survey of astronomical objects are uncovering many interesting, fast-changing objects that have now been poorly understood before, such as GRBs, tidal disruption phenomena, and new types of supernova. In order to characterize these new, exciting events, it is very critical to perform follow-up observations, and 1-2m telescopes can effectively contribute to such efforts. Since 2007, our group has been performing follow-up observations of gamma-ray bursts (GRBs) and interesting transients using BOAO and other KASI facilities. Here, we present results from several key transient studies that were done by using BOAO: (1) tidal disruption event Swift J1644+57; (2) SN 2011fe that occurred in M101; and (3) several GRB events. These study demonstrates the usefulness of BOAO as a powerful transient follow-up facility. Finally, we will discuss how BOAO research activities can possibly be bolstered in this newly emerging field of astronomy.

• 천문학논총
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• 제30권2호
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• pp.699-701
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• 2015

The high plateaus in west China may provide suitable sites for astronomical observations with the institute's middle-range telescopes and possibly with larger telescopes. Under China-Japan collaborations for site survey in west China, we have been conducting searches for good sites and monitoring their characteristics over several years. As recent results of our site survey show, sites in west Tibet are revealed with a high possibility of good astronomical observations. Weather characteristics at Gar in Ali, Tibet, show its high clear-sky ratios, especially in winter, comparable to Mauna Kea, Hawaii. But it has some wind problem in winter, where stronger wind speeds, over 20m/sec, occur frequently even though the sky is clear. To find calmer sites, we have conducted numerical simulations for the Ali area using the Japan Meteorological Agency NonHydrostatic Model. We have found another site, named ZoZo Hill, near Gar. We will continue to monitor the Gar site to clarify weather characteristics over the whole year and hopefully start to negotiate for site monitoring at ZoZo Hill this year.