Gray transits of WD 1145+017 over the visible band
Gray transits of WD 1145+017 over the visible band
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WD 1145 017 在可见光波段的灰色凌日
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Pallé
中科院分区：
文献类型：
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作者：
R. Alonso;S. Rappaport;H. Deeg;E. Pallé
我们用GTC在480 nm到920 nm波长范围内观测到白色矮星WD 1145+017的几次相对较深的凌日。观察涵盖了2016年1月18日约1小时和2016年1月20日约2小时。在那段时间的大部分时间里，白色矮星的灭绝程度各不相同，但时不时会发生四次深度从25%到40%不等的急剧凌日。光谱用棱镜分散，通量数据最终被加总成以0.53、0.62、0.71和0.84 μ m为中心的四个带。经过仔细的归一化，我们发现所有四个波段的通量光变曲线是一致的，包括最深的凹陷。我们使用这些结果来计算埃指数，$阿尔法$，为粒子负责的消光，并发现|$langle alpha
角$|$lesssim 0.06$，假设消光是相对光学薄。我们使用复杂的折射率为常见的矿物设置可能的尘埃颗粒的中值大小的限制，并发现，对于大多数常见的矿物，颗粒大小$lesssim 0.5，mu$m可以排除在外。
We have observed several relatively deep transits of the white dwarf WD 1145+017 with the GTC over the wavelength range 480 nm to 920 nm. The observations covered approximately one hour on 2016 Jan 18 and two hours on 2016 Jan 20. There was variable extinction of the white dwarf during much of that time, but punctuated by four sharp transits with depths ranging from 25% to 40%. The spectrum was dispersed with a grism, and the flux data were ultimately summed into four bands centered at 0.53, 0.62, 0.71, and 0.84 $mu$m. After careful normalization, we find that the flux light curves in all four bands are consistent with being the same, including through the deepest dips. We use these results to compute Angstrom exponents, $alpha$, for the particles responsible for the extinction and find |$langle alpha
angle $| $lesssim 0.06$, assuming that the extinction is relatively optically thin. We use the complex indices of refraction for common minerals to set constraints on the median sizes of possible dust grains, and find that for most common minerals, particle sizes $lesssim 0.5 , mu$m can be excluded.
来自系外行星 KIC 12557548 B 的尘埃云演化的直接证据
DOI：
10.1088/2041-8205/800/2/l21
发表时间：
2015
期刊：
The Astrophysical Journal
影响因子：
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作者：
Bochinski J
通讯作者：
Bochinski J