斯隆数字巡天第五阶段（SDSS-V）发布了其第20个数据集（DR20），包含超过300万条新光谱数据，首次纳入来自南半球的光学观测[1]。这一累积数据集整合了所有历史SDSS观测数据，为天文学家提供了前所未有的全天空视图，揭示了黑洞、稀有恒星、星际气体和数十万个X射线源[1]。
该数据集由三个主要科学项目组成[1]。黑洞映射器（BHM）包含约110万条光学光谱，代表约50万个不同天体[1]；银河系映射器（MWM）包含超过300万条光谱，覆盖150万颗恒星[1]；本地体积映射器（LVM）则对6个目标区域进行了完整光谱扫描，涵盖169个瓦片和约30万条光谱[1]。本次发布同时推出了18个全新或更新的价值添加目录，数据收集时间跨度至2025年2月2日[1]。
The Sloan Digital Sky Survey's fifth phase (SDSS-V) has released its Data Release 20 (DR20), a comprehensive dataset containing over 3 million new spectral measurements that marks a significant milestone in astronomical observation [1]. For the first time, the release incorporates optical observations from the Southern Hemisphere, expanding the survey's reach to provide an unprecedented full-sky view of the universe [1].
The DR20 dataset encompasses multiple coordinated mapping initiatives that together unveil previously hidden cosmic features [1]. The Black Hole Mapper component contains approximately 1.1 million optical BOSS spectra representing roughly 500,000 distinct celestial objects [1], while the Milky Way Mapper includes more than 3 million spectra covering 1.5 million stars [1]. The Local Volume Mapper contributes complete spectral maps across six target regions spanning 169 tiles and approximately 300,000 spectra [1]. Together, these measurements reveal black holes, rare stars, interstellar gas, and tens of thousands of X-ray sources distributed across the sky [1]. The release also introduces 18 newly created or updated value-added catalogs to support further astronomical research [1]. As a cumulative dataset, DR20 incorporates all historical SDSS data collected through February 2, 2025 [1].