Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf WDJ181417.84$-$735459.83, an object originally identified to have a strong infrared excess in the 2MASS and WISE catalogues that we confirmed to be intrinsic to the white dwarf, and likely corresponding to the emission of a dusty disc around the star. The finding of Ca, Fe and Mg absorption lines in two X-SHOOTER spectra of the white dwarf, taken 8 years apart, is further evidence of accretion from a dusty disc. We do not report variability in the absorption lines between these two spectra. Fitting a blackbody model to the infrared excess gives a temperature of 910$\pm50$ K. We have estimated a total accretion flux from the spectroscopic metal lines of $|\dot{\rm M}| = 1.784 \times 10^{9}\, $g s$^{-1}$.

中文翻译：

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在 WDJ181417.84−735459.83 周围偶然发现一个尘土飞扬的圆盘

对白矮星的光谱观察表明，其中许多被系外行星物质污染，可以通过这种方式对其整体成分进行独特探测。我们对 DA 白矮星 WDJ181417.84$-$735459.83 进行了光谱和光度分析，该天体最初在 2MASS 和 WISE 目录中被确定具有强红外余量，我们确认这是白矮星固有的，可能对应恒星周围的尘埃盘的发射。在相隔 8 年的白矮星的两个 X-SHOOTER 光谱中发现的 Ca、Fe 和 Mg 吸收谱线进一步证明了尘埃盘的吸积。我们没有报告这两个光谱之间吸收线的变化。将黑体模型拟合到红外多余部分给出 910$\pm50$K 的温度。我们估计了来自 $|\dot{\rm M}| 光谱金属线的总吸积通量 = 1.784 \times 10^{9}\, $gs$^{-1}$。