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arXiv 1002.0556astro-ph.IM
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UCAC3:天体测量还原

UCAC3: Astrometric Reductions

Charlie T. Finch, Norbert Zacharias, Gary L. Wycoff

摘要:

这里介绍的是从x,y数据到美国海军天文台(USNO)第三CCD星表(UCAC 3)的平均赤经(RA)、赤经(Dec)坐标的天体测量换算的细节。对于这些新的减少,我们使用了超过216,000个CCD曝光。2微米全天巡天(2 MASS)数据被广泛用于探测UCAC数据中的坐标误差和类彗差系统误差,这些误差主要是由4K CCD的电荷传输效率(CTE)差引起的。错误高达约200 MAS已被纠正使用复杂的查找表处理来自残差的多个依赖关系。类似地,场失真和子像素相位误差也已经使用相对于2 MASS的残差进行了评估。总的星等方程是独立于外部星表,仅从UCAC校准场观测得出的。对大多数恒星而言,UCAC 3的观测历元位置的系统误差比以前的星表有更好的改正。第谷-2星表用于获得国际天体参考系(ICRF)上的最终位置。第谷-2参考星的残差显示了一个小的星等方程(取决于分光区),这可能是第谷-2星表中固有的。

英文摘要:

Presented here are the details of the astrometric reductions from the x,y data to mean Right Ascension (RA), Declination (Dec) coordinates of the third U.S. Naval Observatory (USNO) CCD Astrograph Catalog (UCAC3). For these new reductions we used over 216,000 CCD exposures. The Two-Micron All-Sky Survey (2MASS) data are extensively used to probe for coordinate and coma-like systematic errors in UCAC data mainly caused by the poor charge transfer efficiency (CTE) of the 4K CCD. Errors up to about 200 mas have been corrected using complex look-up tables handling multiple dependencies derived from the residuals. Similarly, field distortions and sub-pixel phase errors have also been evaluated using the residuals with respect to 2MASS. The overall magnitude equation is derived from UCAC calibration field observations alone, independent of external catalogs. Systematic errors of positions at UCAC observing epoch as presented in UCAC3 are better corrected than in the previous catalogs for most stars. The Tycho-2 catalog is used to obtain final positions on the International Celestial Reference Frame (ICRF). Residuals of the Tycho-2 reference stars show a small magnitude equation (depending on declination zone) that might be inherent in the Tycho-2 catalog.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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