面向天体测量的矮行星Haumea相对测光试验
Astrometry-Oriented Relative Photometry Test of Dwarf Planet Haumea
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摘要: 使用紫金山天文台姚安观测站80 cm望远镜在2022年2月至4月对矮行星Haumea进行了两轮观测。对所有的观测图像使用干涉条纹剔除技术,并利用相对测光导出了Haumea的仪器星等,最后对两轮光度测量结果进行归一化处理以便联合分析。通过相位弥散最小化(Phase Dispersion Minimization, PDM)方法以及Lomb-Scargle周期图法分别求得了Haumea的自转周期。两种方法求得的自转周期结果仅相差0.072 s,这表明所求周期具有良好的一致性。Haumea光度测量结果显示明显的双峰自转光变曲线,自转周期为3.915 4 ±0.000 2 h,峰峰值幅度为0.26 ±0.01 mag。通过导出的自转光变曲线,最终估计了Haumea由于自转产生的光度变化对位置测量的影响最大为-9~9 mas。这一测光观测对后续高精度天体位置测量具有基础意义。Abstract: The 80 cm telescope at Yaoan Station, Purple Mountain Observatory was used to observe the dwarf planet Haumea for two runs from February to April 2022. Interference fringes were removed from all the frames, and the instrument magnitude of Haumea was derived by relative photometry technology. Then, the photometric data were normalized for combining two observation runs to analysis. The rotation period of Haumea was obtained by the PDM (Phase Dispersion Minimization) method and the Lomb-Scargle Periodogram, respectively. The difference between the results by the two methods was 0.072 s, which showed good consistency. Our photometric results reveal a distinct, double-peaked rotational light curve with a period of 3.915 4 ±0.000 2 h and peak-to-peak amplitude of 0.26 ±0.01 mag. Through the derived rotational light curve, it is finally estimated that the maximum influence of the photometric change of Haumea due to rotation on the astrometry is -9~9 mas. The test has a basic significance for future high-precision astrometry.