Collaborative Research: The Evolution of Magnetic Complexity in Old Sun-like Stars

合作研究：老类太阳恒星的磁复杂性演化

• 批准号: 2205888
• 负责人: Jennifer van Saders
• 金额: $ 44.48万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2205888&HistoricalAwards=false
• 关键词: Collaborative; Research; Evolution; Magnetic; Complexity

Principal Investigators Metcalfe and van Saders will take polarized spectra of a sample of stars to assess the strength and complexity of their magnetic fields. For stars like our Sun, the stellar wind slowly escapes along the star’s magnetic field lines and slows down the rate at which the star rotates over a period of billions of years. This process is called magnetic braking. Slowing rotation leads to a mid-life crisis and the magnetic field generation starts to fail. Stars switch from periods of activity (strong magnetic field with many flares, sunspots, and outbursts) to in-activity (weaker more complex magnetic field with reduced activity). Determining when and how these switches occur will improve our understanding of how stars age. To broaden participation the team plan to lead a 15-week "Survival Skills for Scientists" seminar at the University of Colorado and a summer Research Experience for Teachers at the University of Hawaii.The team will observe 12 stars using the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope combined with contemporaneous spectra using Las Cumbres Observatory's Network of Robotic Echelle Spectrographs (NRES) to determine the level of activity. Follow-up detailed magnetic field maps will be obtained using the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) on the Canada-France-Hawaii Telescope (CFHT). The resulting constraints on how the properties of stellar magnetism depend on rotation and mass beyond middle-age will have implications for theoretical models of angular momentum loss from magnetized stellar winds, the use of gyrochronology as a technique for inferring stellar ages, and will inform predictions of long term "space weather" for the Sun and other planetary systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

首席研究人员Metcalfe和Van Saders将采用恒星样品的偏振光谱，以评估其磁场的强度和复杂性。对于像我们的太阳这样的恒星，恒星风缓慢地沿着恒星的磁场线逃脱，并减慢了恒星在数十亿年内旋转的速度。此过程称为磁制动。旋转减慢导致中年危机，磁场的产生开始失败。恒星从活性周期（具有许多耀斑，黑子和爆发的强磁场）转变为活动性（较弱的磁场较弱，活动降低）。确定这些开关何时以及如何发生将提高我们对恒星年龄的理解。为了扩大参与，团队计划在科罗拉多大学领导15周的“科学家生存能力”，并在夏威夷大学的夏季研究经验和夏季研究经验。该团队将使用Potsdam Echelle echelle polarimetroscic and Spectroscopic仪器（PEPSI）在大型Binocular Telescoper网络中使用laster cumperra cumporsra cobsecome cumperra cobsdam echelle echelle echelle echelle echelle polarimetroscic和spectrarscopic仪式观察到12颗星。光谱仪（NRE）确定活动水平。将使用Echelle SpectroPolarimetric设备获得后续详细的磁场图，以观察加拿大 - 弗朗西 - 弗朗西 - 弗朗西·霍瓦伊望远镜（CFHT）上的恒星（Espadons）。关于恒星磁性的特性如何取决于旋转和中年质量的限制将对理论模型产生影响，这对磁化恒星风的角度动量丧失的理论模型有影响值得通过基金会的智力优点和更广泛的影响评估标准通过评估来获得支持。

项目成果

Constraints on Magnetic Braking from the G8 Dwarf Stars 61 UMa and τ Cet

G8 矮星 61 UMa 和 Ï Cet 对磁制动的约束

• DOI: 10.3847/2041-8213/acce38
• 发表时间: 2023
• 期刊: The Astrophysical Journal Letters
• 作者: Metcalfe, Travis S.;Strassmeier, Klaus G.;Ilyin, Ilya V.;van Saders, Jennifer L.;Ayres, Thomas R.;Finley, Adam J.;Kochukhov, Oleg;Petit, Pascal;See, Victor;Stassun, Keivan G.
• 通讯作者: Stassun, Keivan G.