KMTNET: A NETWORK OF 1.6 M WIDE-FIELD OPTICAL TELESCOPES INSTALLED AT THREE SOUTHERN OBSERVATORIES

TLDR

The Korea Microlensing Telescope Network (KMTNet) is a wide‑field photometric system installed by the Korea Astronomy and Space Science Institute (KASI). The primary scientific goal of KMTNet is to discover numerous extrasolar planets toward the Galactic bulge using gravitational microlensing, especially earth‑mass planets in the habitable zone. KMTNet comprises three 1.6‑m wide‑field optical telescopes with 18k×18k mosaic CCDs covering 2°×2° each, whose data are transmitted to a KASI data center and processed by a dedicated pipeline for continuous 24‑hour monitoring and wide‑field surveys. All three telescopes were successfully installed at CTIO, SAAO, and SSO, forming a network that provides 24‑hour continuous monitoring of Southern Hemisphere targets with image quality meeting the <1.0 arcsec I‑band seeing requirement.

Abstract

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.