标题： 帕洛马和阿波罗点光度测量星际彗星 3I/ATLAS 显示英文标题

标题： Palomar and Apache Point Spectrophotometry of Interstellar Comet 3I/ATLAS

摘要： 2025年7月1日，第三个星际天体3I/ATLAS或C/2025 N1（ATLAS）被发现，其偏心率为$e=6.15 \pm 0.01$，近日点为$q=1.357\pm0.001$天文单位。我们报告使用帕洛马200英寸望远镜和阿波罗点天文台对3I/ATLAS的初始可见光到近红外（420-1000纳米）光谱测光结果。我们测量得到3I/ATLAS在420-700纳米范围内的光谱斜率为19%/100纳米，在700-1000纳米范围内的斜率为更中性的6%/100纳米。我们未检测到明显的发射特征，例如来自C$_2$的特征。 显示英文摘要

摘要： On July 1st 2025 the third interstellar object, 3I/ATLAS or C/2025 N1 (ATLAS), was discovered, with an eccentricity of $e=6.15 \pm 0.01$ and perihelion of $q=1.357\pm0.001$ au. We report our initial visible to near-infrared (420-1000 nm) spectrophotometry of 3I/ATLAS using both the Palomar 200 inch telescope and Apache Point Observatory. We measure 3I/ATLAS to have a red spectral slope of 19 %/100 nm in the 420-700 nm range, and a more neutral 6 %/100 nm slope over 700-1000 nm. We detect no notable emission features such as from C$_2$.