木星伽俐略卫星互掩互食天象的测光技术

发布时间：2018-07-04 21:18

本文选题：木星伽利略卫星 + 去晕　；参考：《暨南大学》2011年硕士论文

【摘要】：通过对行星天然卫星互掩互食天象进行测光可以得到非常准确的天体测量信息,这些信息可以用来进一步改进行卫星的运动理论和历表。这些测光信息可以通过对互掩互食天文图像进行测光所得到的光度变化曲线进行分析得到。俄罗斯学者Emelyanov对2002至2003年所观测到的互掩互食图像得到的多条光度变化曲线进行了描述和分析。然而在文章中没有详述如何对图像进行测光处理才能得到光度变化曲线,在此本文将描述及讨论如何从图像资料中得到光度变化曲线。通过对2003年及2009年在云南天文台和威海天文台两架1米望远镜拍摄的木卫互掩互食天象的图像进行了测光处理,得到了许多情况下的光度变化曲线。对光度变化曲线进行高斯函数拟合最终得到了互掩互食的中间时刻和下降的星等值。在实际图像处理中,很多图像中的目标星处于光晕之内,无法对其进行准确的测光。由于光晕具有良好的对称性,采用木星的中心为对称点进行对称去晕。在文中采用椭圆拟合法对木星进行定心,实验证明采用此方法对木星定心具有较高的精度。去完晕后的背景较为平坦,然后对目标星进行孔径测光。另外发现,孔径大小的选取对于木卫测光最终的结果有较很大的影响,实验表明在1.5倍至4.0倍的半高全宽的孔径下进行测光,所得到的光变曲线具有良好的稳定性。在星象互食事件中,通常存在多颗参考星,应对多颗参考星进行对比测光,以得到更优的光变曲线。
[Abstract]:Very accurate astrometric information can be obtained by photometry of the mutual eclipse of planetary natural satellites, which can be used to further change the theory and calendar of satellite motion. These photometric information can be obtained by analyzing the photometric variation curves obtained from the photometry of the masking and eating astronomical images. Emelyanov, a Russian scholar, described and analyzed a number of photometric curves obtained from the masking and eating images from 2002 to 2003. However, there is no detailed description of how to process the image to get the photometric change curve. In this paper, we will describe and discuss how to get the photometric change curve from the image data. Based on the photometric processing of the images of two 1-meter telescopes taken by Yunnan Observatory and Weihai Observatory in 2003 and 2009, the photometric variation curves were obtained in many cases. The Gao Si function fitting of the photometric variation curve results in the intermediate time of mutual masking and the decreasing star equivalent. In the actual image processing, the target stars in many images are in halo, so they can not be accurately measured. Due to the good symmetry of the halo, the center of Jupiter is used to remove the halo symmetrically. In this paper, the elliptical fitting method is used to center Jupiter, and the experimental results show that this method has a high accuracy for Jupiter centering. After the halo, the background is flat, and then the target star aperture photometry. In addition, it is found that the selection of aperture size has a great influence on the final results of wood and satellite photometry. The experimental results show that the photorefractive curves obtained by the method are stable in the range of 1.5 to 4.0 times of the full width of the maximum aperture. In the event of mutual eclipse of stars, there are usually many reference stars, which should be compared and photometric in order to obtain a better curve of light variation.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：P125;TP391.41

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