Exploring the Relationship Between Stellar Mass and Planet Occurrence

John Johnson博士被授予NSF天文学和天体物理学博士后奖学金，在夏威夷大学天文研究所开展一项研究和教育计划。已知附近有150多颗恒星存在行星伴星，而这些宿主恒星的物理性质在今天探测到的行星和它们形成的星周环境之间提供了重要的联系。确定恒星质量和行星出现之间的关系，为行星形成的核心吸积模型提供了重要的测试，该模型预测了恒星与行星的比例如何随着恒星质量的增加而增加。为了测量行星的出现率与质量的关系，PI将在凯克天文台对中等质量亚巨星进行精密多普勒测量。亚巨星是理想的行星搜索候选者，因为它们的光谱线更窄，与它们早期类型的祖先相比，大气噪音更低。这次搜索探索了一个独特的恒星参数空间，并将使目前凯克多普勒探测的质量范围增加一倍。约翰逊还将在小学实施一项教育推广计划，使用实践和多媒体活动，将行星科学和州强制科学标准结合起来。这些教案将与火奴鲁鲁地区的四年级和五年级教师合作教授。这些活动旨在带领学生踏上一段旅程，从太阳开始，穿过我们太阳系的行星，最终到达最近在其他恒星周围发现的奇异世界。作为少数族裔的榜样，约翰逊博士处于独特的地位，可以鼓励年轻的、代表性不足的学生追求天文学事业。

Dr. John Johnson is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the Institute for Astronomy at the University of Hawaii. Over 150 nearby stars are known to harbor planetary companions, and the physical properties of these host stars provide an important link between the planets detected today and the circumstellar environments from which they formed. Determining the relationship between stellar mass and planet occurrence provides an important test of the core accretion model of planet formation, which predicts how the fraction of stars with planets increases with stellar mass. To measure the occurrence rate of planets as a function of mass, the PI will conduct a precision Doppler survey of intermediate-mass subgiants at Keck Observatory. Subgiants are ideal planet-search candidates due to their narrower spectral lines and lower atmospheric noise compared to their early-type progenitors. This search probes a unique stellar parameter space and will double the mass range of current Keck Doppler surveys.Dr. Johnson will also implement a program of educational outreach in elementary schools using hands-on and multimedia activities that merge planetary science and state-mandated science standards. The lesson plans will be taught in collaboration with Honolulu-area 4th- and 5th-grade teachers. The activities are designed to take students on a journey that begins at the Sun, progresses through the planets of our Solar System, and culminates with the exotic worlds recently discovered around other stars. By serving as a minority role model, Dr. Johnson is uniquely positioned to encourage young, underrepresented students to pursue careers in astronomy.