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

为了获得行星、恒星和星系的最清晰图像，天文学家必须使用创新技术来校正地球大气层湍流造成的图像模糊。这项技术最令人兴奋的用途之一是成像附近恒星周围的行星。这个团队的目标是建立一个设备，使用来自主机星星（行星轨道的星星）的红外光。该设备将用于世界上最大的望远镜之一，位于夏威夷莫纳克亚的凯克II望远镜。该系统通过快速改变仪器内部镜子的形状来抵消地球大气中的“涟漪”效应。首席研究员沿着一名博士后研究员、暑期实习生以及来自夏威夷和加州的研究生和本科生将在150颗小“矮”星周围搜寻行星。他们的结果将通过凯克数据档案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以及为即将到来的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）能力的实际需要的推动下，提议者试图为凯克天文台制造一个在L波段工作的系统。这样一个系统所需的红外探测器技术现在已经存在（大部分是通过NSF的资助），并将被提议者用于为凯克II望远镜建造一个近红外高阶金字塔波前传感器。然后，该系统将被用来进行一个L波段（3微米）日冕成像调查的150 M矮星与凯克设施仪器，NIRC2。该小组将对L波段调查中发现的任何系外行星候选者进行后续低分辨率狭缝光谱观测。请注意，M矮星太暗，无法以足够的对比度和空间分辨率进行观测，无法用现有的光学AO系统检测（甚至是大质量的）系外行星。在凯克提出的近红外波前传感系统的发展可以被视为一种使能技术，可以导致在其他公开可用的天文台制造类似的单位。还应注意的是，NIR波前传感可用于将自然引导星星AO系统的性能扩展到较暗的目标，并将天空覆盖范围增加到只有光学模糊或非常红的引导星可用的区域。

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.