• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.343-348
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• 2012

This paper described an off-axis five-mirror-anastigmatic telescope. It is composed of three aspheric surfaces and one spherical surface while the third mirror and fifth mirror have the same parameters at the same place. This configuration is useful for having wide field of view. The strip full field of view for the near infrared telescope is $20^{\circ}{\times}0.2^{\circ}$. The entrance pupil is located in front of the first mirror. There is an intermediate image between the second mirror and the third mirror. The entrance pupil diameter is 100 mm and the effective focal length is 250 mm. The spectral range is $0.85-1.75{\mu}m$. The pixel pitch is $15{\mu}m$. The image quality is near the diffraction limit. Some methods were used to restrain the stray light such as a field stop near the intermediate image, the baffle, the narrow-band pass filter and a stop in front of the focal plane.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.181-182
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• 2012

Using the AKARI mid-infrared all-sky survey catalogue, we are searching for debris disks which are important objects as an observational clue to on-going planetary system formation. Debris disk candidates are selected through a significant excess of the measured flux over the predicted flux for the stellar photospheric emission at $18{\mu}m$. The fluxes were originally estimated based on the near-infrared spectral energy distributions (SEDs) of central stars constructed from the 2MASS J-, H-, and Ks-band fluxes. However, we found that in many cases the 2MASS photometry has large errors due to saturation in the central part of a star image. Therefore we performed follow-up observations with the IRSF 1.4m near-infrared telescope in South Africa to obtain accurate fluxes in the J-, H-, and Ks-bands. As a result, we have succeeded in improving the SEDs of the central stars. This improvement of the SEDs allows us to make more reliable selection of the candidates.

• 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) ${\~}13.42{\pm}0.12$).

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.64.1-64.1
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• 2011

MIRIS (Multipurpose Infra-Red Imaging System), is a small infrared space telescope which is being developed by KASI, as the main payload of Science and Technology Satellite 3 (STSAT-3). Two wideband filters (I and H) of the MIRIS enables us to study the cosmic infrared background by detecting the absolute background brightness. The narrow band filter for Paschen ${\alpha}$ emission line observation will be employed to survey the Galactic plane for the study of warm ionized medium and interstellar turbulence. The opto-mechanical design of the MIRIS is optimized to operate around 200K for the telescope, and the cryogenic temperature around 90K for the sensor in the orbit, by using passive and active cooling technique, respectively. The engineering and qualification model of the MIRIS has been fabricated and successfully passed various environmental tests, including thermal, vacuum, vibration and shock tests. The flight model was also assembled and is in the process of system optimization to be launched in 2012 by a Russian rocket. The mission operation scenario and the data reduction software is now being developed. After the successful mission of FIMS (the main payload of STSAT-1), MIRIS is the second Korean space telescope, and will be an important step towards the future of Korean space astronomy.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.55.1-55.1
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• 2010

The Giant Magellan Telescope (GMT) is a 24.5m diameter optical/infrared telescope. Its seven 8.4m primary mirrors give it a collecting area equivalent to a 21.4m filled aperture. The ten GMT partners are constructing the telescope at the Las Campanas Observatory in Chile with first light planned for the end of 2018. In this paper, we describe the plans for the first-generation focal plane instrumentation for the telescope. The GMTO Corporation has solicited studies for instruments capable of carrying out the broad range of objectives outlined in the GMT Science Case. Six instruments have been selected for 14 month long conceptual design studies. We describe the features of these instruments and give examples of the major science questions that they can address.

• The Bulletin of The Korean Astronomical Society
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• v.29 no.2
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• pp.28.2-28.2
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• 2004

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.331-335
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• 2017

We present project updates of the next-generation infrared space mission SPICA (Space Infrared Telescope for Cosmology and Astrophysics) as of November 2015. SPICA is optimized for mid- and far-infrared astronomy with unprecedented sensitivity, which will be achieved with a cryogenically cooled (below 8 K), large (2.5 m) telescope. SPICA is expected to address a number of key questions in various fields of astrophysics, ranging from studies of the star-formation history in the universe to the formation and evolution of planetary systems. The international collaboration framework of SPICA has been revisited. SPICA under the new framework passed the Mission Definition Review by JAXA in 2015. A proposal under the new framework to ESA is being prepared. The target launch year in the new framework is 2027/28.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.56.2-56.2
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• 2010

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation astronomical mission optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. Due to its high angular resolution and unprecedented sensitivity, SPICA will enable us to resolve many key issues in the present-day astronomy. As an international collaboration, KASI proposed the near-infrared instrument which is composed of two parts; (1) science observation with the capability of imaging and spectroscopy covering $0.7{\mu}m$ to $5{\mu}m$ (FPC-S) (2) fine guiding to stabilize and improve the attitude (FPC-G). Here, we introduce the science programs proposed for SPICA/FPC-S.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.621-624
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• 2015

We present the current status (as of August 2014) of SPICA (Space Infrared Telescope for Cosmology and Astrophysics), which is a mission optimized for mid- and far-infrared astronomy with a cryogenically cooled 3m-class telescope. SPICA is expected to achieve high spatial resolution and unprecedented sensitivity in the mid- and far-infrared, which will enable us to address a number of key problems in present-day astronomy, ranging from the star-formation history of the universe to the formation of planets. We have carried out the "Risk Mitigation Phase" activity, in which key technologies essential to the realization of the mission have been extensively developed. Consequently, technical risks for the success of the mission have been significantly mitigated. Along with these technical activities, the international collaboration framework of SPICA has been revisited, which resulted in la arger contribution from ESA than that in the original plan. To enable the ESA participation under the new framework, a SPICA proposal to ESA is under consideration as a medium-class mission under the framework of the ESA Cosmic Vision. The target launch year of SPICA under the new framework is the mid-2020s.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.82.1-82.1
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• 2013

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation infrared space telescope optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. Owing to unprecedented sensitivity and high spatial resolution, the focal plane instruments are expected to perform the confusion-limited observation. The SPICA will challenge to reveal many astronomical key issues from the star-formation history of the universe to the planetary formation. The Korean 5contribution to SPICA as an international collaboration is the development of the near-infrared instrument, FPC (Focal Plane Camera). The Korean consortium for FPC proposed a key system instrument for the purpose of a fine guiding (FPC-G) complementing the AOCS (Attitude and Orbit Control System). The back-up instrument of FPC-G, FPC-S will be responsible for the scientific observations as well. Through the international review process, we have revised the scientific programs and made the feasibility study for the fine guiding system. Here, we report the current status of SPICA/FPC project.