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

为了获得行星、恒星和星系最清晰的图像，天文学家必须使用创新的技术来纠正由地球大气湍流引起的图像模糊。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。这个团队的目标是制造一种利用主星（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，夏威夷莫纳克亚的凯克二号望远镜。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“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州的研究生和本科生一起，在150颗小“矮星”周围寻找行星。他们的研究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的推动下，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，建议者寻求为凯克天文台生产一个在l波段运行的系统。这种系统所需的红外探测器技术现在已经存在（大部分由美国国家科学基金会资助），并将被提议者用于为凯克II号望远镜建造一个近红外、高阶、金字塔波前传感器。然后，该系统将使用凯克设施仪器NIRC2对~150 M矮星进行l波段（3微米）日冕成像调查。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。需要注意的是，m矮星太过微弱，没有足够的对比度和空间分辨率，无法用现有的光学AO系统来探测（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能被视为一种使能技术，可能导致在其他公开可用的天文台制造类似的单元。还应该指出的是，近红外波前传感可用于将自然导星AO系统的性能扩展到较弱的目标，并增加天空覆盖到只有光学遮挡或非常红的导星可用的区域。

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.