CAREER: Monitoring for Signs of Magnetospheres Around Extrasolar Planets

恒星将物质喷射到它们周围的空间。这些抛射产生了从恒星向外移动的冲击波，并以低无线电频率的信号爆发的形式出现。当这些冲击波击中这些其他有磁层的恒星(如地球)周围的行星时，这些行星的无线电信号强度也应该会增加。如果我们探测到一颗行星发出的这种无线电辐射，我们就知道它有一个磁层，可以保护地球免受外部辐射，并保护任何可能存在的生物。研究人员将使用欧文斯谷长波长阵列射电望远镜，在5年内连续搜索2500个行星系统的这些信号。这个项目服务于国家利益，因为它有助于我们寻找其他恒星周围可能存在生命的行星，以及我们对这些行星的性质的理解。调查人员将与帕萨迪纳联合学区的高中生合作，为SpaceWeather.com的头版连续更新射电望远镜看到的低频射电天空，接触到广泛的公众受众。恒星日冕物质抛射在低频(通常为100兆赫)产生明亮的射电爆发，产生的冲击波通过日冕和行星际介质传播。类似地，具有磁层的系外行星遇到这些冲击波时，射电光度也会增加数量级。行星磁层充当了潜在生物圈的屏障，使其免受来自宿主星和其他星球的有害高能粒子的伤害。在系外行星上探测到这种射电发射将是非常重要的，因为它允许直接测量该行星的磁场强度，表明该行星的大气是否能够在其主恒星的强烈磁活动中幸存下来。研究人员将使用欧文斯谷长波长阵列(OVRO-LWA)在5年内连续监测25秒(2500个系统)内的每个恒星系统，以努力探测到此类事件。除了第一次直接确认系外系外磁层的存在、强度和范围，探测还允许推断系外行星S内部的性质，并提供表征行星自转速度以及自转轴和轨道轴倾角等物理性质的能力。调查人员将与帕萨迪纳联合学区的高中生合作，开发一种公开可访问的、基于网络的、实时更新的低频无线电天空，如OVRO-LWA所见。这一实时更新将在SpaceWeather.com的首页持续播放，让这些学生接触到科学数据和广泛的公众受众之间的接口。

Stars eject material into the space surrounding them. Theses ejections create shock waves that move outward from the stars, and show up as bursts of signal at low radio frequencies. When these shock waves hit planets around these other stars that have magnetospheres (like the Earth), the planets should also increase in radio signal strength. If we detect this radio emission from a planet, we learn that it has a magnetosphere that can shield the planet from outside radiation and protect any biology that could be present. The investigator will use the Owens Valley Long Wavelength Array radio telescope to search for these signals from 2500 planetary systems continuously over 5 years. This project serves the national interest as it helps our search for planets around other stars that could have life, and our understanding of the properties of these planets. The investigator will work with high school students from the Pasadena Unified School District to make a live continuous update of the low frequency radio sky seen by the radio telescope for the front page of spaceweather.com, reaching a broad, public audience. Stellar coronal mass ejections produce bright radio bursts at low frequencies (typically 100 MHz), which are generated as the resulting shockwave propagates through the corona and interplanetary medium. Similarly, exoplanets with magnetospheres that encounter these shockwaves can also increase in radio luminosity by orders of magnitude. Planetary magnetospheres serve as shields for potential biospheres from harmful high-energy particles from the host star and beyond. The detection of this radio emission at an exoplanet would be very significant, as it allows the direct measurement of the magnetic field strength of the planet, indicating whether the atmosphere of the planet can survive the intense magnetic activity of its host star. The investigator will use the Owens Valley Long Wavelength Array (OVRO-LWA) to monitor every stellar system out to 25 parsecs (2500 systems) continuously for a 5-year period, in an effort to detect such events. As well as providing the first direct confirmation of the presence, strength and extent of an exoplanetary magnetosphere, a detection allows inference of the nature of the exoplanet?s interior and provides the capability to characterize physical properties such as planetary rotation rate and inclination of rotational and orbital axes. The investigator will work with high school students from the Pasadena Unified School District to develop a publicly accessible, web-based, live update of the low frequency radio sky, as seen by the OVRO-LWA. This live update will be continuously shown on the front page of spaceweather.com, placing these students at the interface between scientific data and a broad, public audience.