Examining Planets around Other Stars through Very Precise Infrared Imaging at the Keck Observatory

为了获得最清晰的行星、恒星和星系的图像，天文学家必须使用创新的技术来校正地球大气中的湍流造成的图像模糊。这项技术最令人兴奋的用途之一是对附近恒星周围的行星进行成像。该团队的目标是建造一种利用主恒星(该行星绕其运行的恒星)发出的红外光工作的设备。该装置将用于世界上最大的望远镜之一，位于夏威夷莫纳凯亚的凯克II望远镜。该系统的工作原理是快速改变仪器内部镜子的形状，以抵消地球大气层中“涟漪”的影响。首席研究员将与一名博士后研究员、暑期实习生以及来自夏威夷和加利福尼亚州的研究生和本科生一起，寻找围绕150颗小矮星的行星。他们的结果将通过凯克数据档案馆提供给更广泛的科学界。在研究低质量M矮星周围年轻行星系统的科学愿望的推动下，以及为即将到来的新一代30米级分段镜望远镜开发近红外(NIR)波前传感和自适应光学(AO)能力的实际需要，提出者试图为凯克天文台生产一个运行在L波段的系统。这样一个系统所需的红外探测器技术现在已经存在(很大程度上是由NSF资助的)，并将被提议者用来为Keck II望远镜建造近红外、高阶、金字塔形波前传感器。然后，这个系统将被用来用Keck设备仪器NIRC2对~150M矮星进行L波段(3微米)的日冕成像测量。该团队将对L波段调查中发现的任何系外行星进行后续的低分辨率狭缝光谱观测。请注意，M矮星太微弱，无法以足够的对比度和空间分辨率来观测，无法用现有的光学AO系统探测(甚至是大质量的)系外行星。Keck拟议的近红外波前传感系统的开发可被视为一项使能技术，可导致在其他可公开获得的观测站制造类似的单元。还应注意的是，近红外波前传感可用于将自然导航星AO系统的性能扩展到较暗的目标，并将天空覆盖范围扩大到只有光学遮挡或非常红的导航星可用的区域。

To get the sharpest images of planets, stars and galaxies, astronomers must use innovative techniques that correct for the blurring of images caused by turbulence in the earth's atmosphere. One of the most exciting uses of this technology is imaging planets around nearby stars. This team aims to build a device that works using infrared light from the host star (the star that the planet orbits). The device will be used on one of the world's largest telescopes, the Keck II telescope on Maunakea, Hawaii. The system works by rapidly changing the shape of mirrors inside the instrument to counteract the effect of "ripples" in the earth's atmosphere. The principal investigator, along with a postdoctoral researcher, summer interns, and graduate and undergraduate students from Hawaii and California, will search for planets around 150 small "dwarf" stars. Their results will be made available to the broader science community through the Keck Data Archive.Driven by the scientific desire to study young planetary systems around low-mass M-dwarfs, and the practical need to develop near-infrared (NIR) wavefront sensing and adaptive optics (AO) capabilities for the upcoming generation of 30 meter class segmented-mirror telescopes, the proposers seek to produce a system that operates in the L-band for the Keck observatory. The IR detector technology needed for such a system now exists (in large part through funding by NSF) and will be used by the proposers to build a near-IR, high-order, pyramid wavefront sensor for the Keck II telescope. This system will then be used to conduct an L-band (3 micron) coronagraphic imaging survey of ~150 M dwarfs with the Keck facility instrument, NIRC2. The team will conduct follow-up low-resolution slit spectroscopy observations of any exoplanet candidates found in the L-band survey. Note that M-dwarfs are too faint to observe with sufficient contrast and spatial resolution to detect (even massive) exoplanets with existing optical AO systems. The development of the proposed NIR wavefront sensing system at Keck may be viewed as an enabling technology that could lead to the fabrication of similar units at other, publicly available observatories. It should also be noted that NIR wavefront sensing can be used to extend the performance of natural guide star AO systems to fainter targets, and to increase the sky coverage to regions where only optically obscured or very red guide stars are available.