CAREER: Monitoring for Signs of Magnetospheres Around Extrasolar Planets

恒星向周围的空间喷射物质。这些喷射产生的冲击波从恒星向外移动，并以低无线电频率的信号爆发形式出现。当这些冲击波击中这些具有磁层的其他恒星（如地球）周围的行星时，行星的无线电信号强度也会增加。如果我们探测到来自一颗行星的这种无线电发射，我们就会知道它有一个磁层，可以保护行星免受外部辐射，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阵列射电望远镜在5年内连续搜索来自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可能有生命的其他恒星周围的行星，以及我们对这些行星性质的理解。调查人员将与帕萨迪纳联合学区的高中生合作，为spaceweather.com的头版实时连续更新射电望远镜看到的低频射电天空，以达到广泛的公众受众。恒星日冕物质抛射产生低频（通常为100 MHz）的明亮无线电爆发，这是由于产生的冲击波通过日冕和行星际介质传播而产生的。类似地，具有磁层的系外行星遇到这些冲击波也可以使射电光度增加几个数量级。行星磁层是潜在生物圈的保护层，防止来自宿主星星和更远的地方的有害高能粒子。在系外行星上探测到这种无线电发射将是非常重要的，因为它可以直接测量行星的磁场强度，表明行星的大气层是否能够在其宿主星星的强烈磁场活动中幸存下来。研究人员将使用欧文斯谷长波长阵列（OVRO-LWA）连续5年监测25秒差距（2500个系统）的每个恒星系统，以检测此类事件。除了提供第一次直接确认系外行星磁层的存在、强度和范围外，探测还可以推断系外行星的性质。的内部，并提供了表征物理特性，如行星旋转速率和旋转和轨道轴的倾斜度的能力。研究人员将与帕萨迪纳联合学区的高中生合作，开发一个可公开访问的、基于网络的、实时更新的低频无线电天空，正如OVRO-LWA所看到的那样。这一实时更新将持续显示在spaceweather.com的首页上，将这些学生置于科学数据和广泛的公众受众之间的界面。

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.