Exploring the Relationship Between Stellar Mass and Planet Occurrence

约翰约翰逊博士被授予NSF天文学和天体物理学博士后奖学金，在夏威夷大学天文学研究所开展研究和教育计划。已知有超过150颗邻近恒星拥有行星伴星，这些主星的物理性质提供了今天发现的行星与它们形成的星周环境之间的重要联系。确定恒星质量和行星出现之间的关系提供了一个重要的测试核心吸积模型的行星形成，预测恒星的行星的分数如何增加与恒星质量。为了测量行星的出现率作为质量的函数，PI将在凯克天文台对中等质量的亚巨星进行精确的多普勒测量。次巨星是理想的行星搜索候选者，因为它们的光谱线较窄，与早期类型的祖先相比，大气噪音较低。这项研究探索了一个独特的恒星参数空间，将使目前凯克多普勒调查的质量范围扩大一倍。约翰逊博士还将在小学实施一项教育推广计划，利用实践和多媒体活动，将行星科学和国家规定的科学标准结合起来。课程计划将与檀香山地区的四年级和五年级教师合作教授。这些活动旨在让学生踏上从太阳开始的旅程，通过我们太阳系的行星，并以最近在其他恒星周围发现的异国情调的世界为高潮。通过作为少数民族的榜样，约翰逊博士具有独特的地位，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.