ALICE: The Ultraviolet Imaging Spectrograph aboard the New Horizons Pluto-Kuiper Belt Mission
S. Alan Stern, David C. Slater, John Scherrer, John Stone, Greg Dirks, Maarten Versteeg, Michael Davis, G. R. Gladstone, Joel Wm. Parker, Leslie A. Young, O. H. W. Siegmund
备注：
24 pages, 29 figures, 2 tables; To appear in a special volume of Space Science Reviews on the New Horizons mission
The New Horizons ALICE instrument is a lightweight (4.4 kg), low-power (4.4 Watt) imaging spectrograph aboard the New Horizons mission to Pluto/Charon and the Kuiper Belt. Its primary job is to determine the relative abundances of various species in Pluto's atmosphere. ALICE will also be used to search for an atmosphere around Pluto's moon, Charon, as well as the Kuiper Belt Objects (KBOs) that New Horizons hopes to fly by after Pluto-Charon, and it will make UV surface reflectivity measurements of all of these bodies as well. The instrument incorporates an off-axis telescope feeding a Rowland-circle spectrograph with a 520-1870 angstroms spectral passband, a spectral point spread function of 3-6 angstroms FWHM, and an instantaneous spatial field-of-view that is 6 degrees long. Different input apertures that feed the telescope allow for both airglow and solar occultation observations during the mission. The focal plane detector is an imaging microchannel plate (MCP) double delay-line detector with dual solar-blind opaque photocathodes (KBr and CsI) and a focal surface that matches the instrument's 15-cm diameter Rowland-circle. In what follows, we describe the instrument in greater detail, including descriptions of its ground calibration and initial in flight performance.
Collision rates in the present-day Kuiper Belt and Centaur Regions: Applications to surface activation and modification on Comets, Kuiper Belt Objects, Centaurs, and Pluto-Charon
Time-Resolved Photometry of Kuiper Belt Objects: Rotations, Shapes and Phase Functions
我们提出了一个系统的调查的基础上广泛的光学数据莫纳克亚的海王星外天体的旋转光变曲线。在我们的样本中，13个天体中有4个（相当于31%）（（33128）1998 BU 48，2000 GN 171，（20000）Varuna和1999 KR 16）显示出峰-峰范围> 0.15等的光变曲线。在通过将我们的数据与文献中可靠确定的光变曲线相结合而获得的更大样本中，22个物体中有7个（32%）显示出显著的（> 0.15星等范围）光变曲线。大约23%的采样对象的光变曲线范围> 0.4星等。奇怪的是，这些天体非常大（直径大于250公里，假设旋度为0.04），在没有自转的情况下，由于自压缩，应该接近球形。我们提出，大振幅，短周期的对象是旋转扭曲，低密度碎石桩。从统计学上看，海王星外天体的球形度低于主带小行星，这表明形成时期可能导致了更高的比角动量。除了旋转光变曲线，我们还测量了7个柯伊伯带天体在0到2度相位角范围内的相位变暗。与冥王星不同的是，测量值显示陡峭的斜坡和适度的反对浪潮，表明低散射多孔表面材料的后向散射。
