Astronomical observation data produced by a Korean observation facility has been made available to astronomers worldwide for the first time. It marks the first occasion that ground-based telescope data created by Korea has been distributed globally through an international data center, a development researchers say elevates the country's astronomical research capabilities to a new level.
A research team led by Professor Im Myung-shin of the Department of Physics and Astronomy at Seoul National University announced Saturday that it has released image maps and celestial catalogs obtained by surveying the southern sky using the Korea Microlensing Telescope Network (KMTNet), developed and operated by the Korea Astronomy and Space Science Institute (KASI). The data has been made public worldwide through the Astro Data Lab at the U.S. NOIRLab and the Strasbourg Astronomical Data Center (CDS) in France.
KASI's southern sky survey project, "KS4," began in 2019 and has conducted observations over more than 600 days.
The team processed data obtained from KMTNet's three telescopes in Chile (CTIO), South Africa (SAAO), and Australia (SSO) into scientific-quality data through a dedicated pipeline developed by Seoul National University. As a result, the team produced a catalog of more than 200 million celestial objects in the southern sky along with high-quality images ready for scientific research. Through this international data center release, the materials are now available for anyone in the world to use.
The primary purpose of the data release is to enable faster detection of "transient objects" that appear suddenly, such as gravitational waves or gamma-ray bursts. Detecting such objects requires reference images that capture the normal appearance of the sky, but until now, uniform and deep reference images have not existed for the southern sky.
Previous southern sky survey projects either covered wide areas but observed only bright objects, or captured fainter objects but left some regions uncovered. The KS4 data overcomes these limitations by observing the sky uniformly and comprehensively while reaching a moderate brightness limit (approximately magnitude 22 to 23.5) that can identify relatively faint objects. The data is expected to serve as reference images for quickly identifying optical counterparts when gravitational wave events occur in the future.
The research team also explained that KS4 is the only large-scale survey project that encompasses all of the B, V, R, and I filters widely used in astronomical research.
"Until now, large-scale southern sky surveys have been led by the United States, Europe, and Australia, but this time we are providing data to researchers around the world using a Korean facility," Professor Im said. "This signifies Korea's growth from a consumer of foreign data to a supplier."
Research Professor Jang Seo-won added, "This is a valuable case in which the southern sky observation data we produced has been recognized for its importance and released through major international astronomical data centers."
Starting with this first release of observation data, the team plans to continue additional observations through December 2029, the remaining period of the project.
