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The Space Telescope Science Institute (STScI) Director has decided to devote up to 1000 orbits of Director.s Discretionary time in observing Cycles 27-29 to a new Hubble Ultraviolet Legacy program focused on star formation and associated stellar physics. This new program comma ULLYSES (UV Legacy Library of Young Stars as Essential Standards) comma will provide a UV spectroscopic reference sample of young (< 10 Myr) high- and low-mass stars. It will target virgul165 OB stars in the Magellanic Clouds and lower metallicity galaxies in the Local Group comma and virgul67 T Tauri stars and brown dwarfs in the Milky Way. In addition comma ULLYSES will monitor 4 typical T Tauri stars over different rotational phases through at least three rotation periods comma and over timescales of months to years. The resulting library will provide template spectra of massive stars at metallicities substantially below the well studied comma while the low mass sample will cover a wide range of ages comma accretion rates comma and masses comma including objects down to well below 0.5 M_sun. The legacy of this large UV dataset on the first 10 Myr of stellar evolution will be enhanced by complementary datasets obtained by the scientific community. In addition to the core goals of the program related to stellar astrophysics of low and high mass stars comma this data will also enable exciting science in the fields of ISM comma CGM comma jets comma and exoplanets. ULLYSES will be modeled after the Frontier Fields programdoublePoint all data obtained will be non-proprietary. The implementation team at STScI is developing high-level science data products and a sophisticated database and website for disseminating data from the ULLYSES program and ancillary datasets for the ULLYSES target sample from space and ground-based facilities.

空间望远镜科学研究所（Space Telescope Science Institute, STScI）所长已决定，将第27至29号观测周期内最多1000个所长酌情分配观测轨道的时长，投入一项全新的哈勃紫外遗产项目（Hubble Ultraviolet Legacy program），聚焦恒星形成与相关恒星物理学研究。该项目ULLYSES（紫外遗产青年恒星标准库，UV Legacy Library of Young Stars as Essential Standards）将构建年龄小于10百万年的大质量与小质量恒星的紫外光谱参考样本。项目将观测麦哲伦云与本星系群内低金属丰度星系中的VIRGUL165型OB星，以及银河系内的VIRGUL67型金牛T星（T Tauri stars）与褐矮星（brown dwarfs）。此外，ULLYSES将监测4颗典型金牛T星在不同自转相位下的光谱，观测时长覆盖至少3个自转周期，时间跨度为数月至数年。最终构建的光谱库将提供金属丰度远低于已被充分研究的大质量恒星的模板光谱；而小质量样本将覆盖宽泛的年龄、吸积率与质量范围，包含质量远低于0.5倍太阳质量（M☉）的天体。这套针对恒星演化最初10百万年的大型紫外数据集的科学遗产价值，将通过科学界获取的补充数据集进一步强化。除围绕大质量与小质量恒星天体物理学的核心研究目标外，该数据集还将推动星际介质（Interstellar Medium, ISM）、星系周介质（Circumgalactic Medium, CGM）、天体喷流与系外行星（exoplanets）领域的前沿科学研究。该项目将参考哈勃前沿场项目（Frontier Fields program）模式开展，所有获取的数据均为非专属公开数据。STScI的实施团队正在开发高级科学数据产品，以及用于分发ULLYSES项目数据与ULLYSES目标样本配套数据集的专业数据库与网站，这些配套数据集来自空间与地面观测设施。