现在你看见我，现在你看不见我：白矮星因解体星子产生的尘埃和碎片而发生的深度、长时标掩食事件
Now you see me, now you don't: Deep, long-lived obscuration events of white dwarfs by dust and debris from disintegrating planetesimals
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中文总结 AI 辅助
报告六颗白矮星经历单次深度长时标掩食事件，由解体星子碰撞级联产生尘埃所致，并发现首个红外增亮与光学掩食同时发生的案例。
中文摘要 AI 辅助
白矮星周围的凌星尘埃和碎片为行星解体提供了直接视角。我们报告了六颗此前不变化的、经历了单次深度掩食事件的白矮星，其中包括ZTF~J2327+0019，它完全消失了一年多。这些发现使已确认的碎片凌星白矮星数量增加到20颗。此外，通过对兹威基瞬变设施（ZTF）的负警报进行系统搜索，并辅以测光和光谱观测，还识别出三颗热的（$T\approx 55000$--$92000$ K）不规则变星作为候选碎片宿主。这六次已确认的事件持续数周至数年，掩食深度达到25%--100%，并且在8年的ZTF基线内没有表现出重复。因此，它们比先前已知系统典型的、重复出现的分钟级凌星要深得多且寿命长得多。观测到的红化与尘埃消光一致，高速测光在几个系统中揭示了分钟级结构，表明有快速移动的物质靠近白矮星。ZTF~J2327+0019还同时显示出WISE红外增亮，这是首次观测到白矮星中红外增亮与光学掩食同时发生。六个宿主中的两个，一个DAZ和一个DBZ，具有强烈的金属增丰，其吸积率在其光谱类型中属于最高之列，最小吸积质量分别为$3.5\times 10^{19}$和$2\times 10^{24}$克。我们将这些一次性掩食事件解释为星子残骸与先前存在的星周碎片之间的碰撞，触发了碰撞级联：短时标变化追踪了产生尘埃的碎片横越恒星，而较慢的变化则追踪了光学厚尘埃结构的形成和清除。相比之下，ZTF~J0436+5728显示出5.910小时的相干周期，与一个在潮汐瓦解半径附近脱落物质的岩石天体一致。
英文摘要
Transiting dust and debris around white dwarfs provide a direct view of planetary disruption. We report six previously non-variable white dwarfs that underwent single, deep obscuration events, including ZTF~J2327+0019, which fully disappeared for more than a year. These discoveries raise the number of confirmed debris-transit white dwarfs to 20. In addition, the systematic search of negative alerts from the Zwicky Transient Facility (ZTF), followed by photometric and spectroscopic observations, also identified three hot ($T\approx 55000$--$92000$ K) irregular variables as candidate debris hosts. The six confirmed events last weeks to years, reach transit depths of 25--100%, and show no recurrence over the 8-yr ZTF baseline. They are therefore much deeper and longer lived than the recurring, minute-scale transits typical of previously known systems. The observed reddening is consistent with dust extinction, and high-speed photometry reveals minute-scale structure in several systems, indicating rapidly moving material close to the white dwarf. ZTF~J2327+0019 also shows a simultaneous WISE infrared brightening, the first observed coincidence of infrared brightening and optical obscuration in a white dwarf. Two of the six hosts, one DAZ and one DBZ, are strongly metal enriched, with accretion rates among the highest known for their spectral types and minimum accreted masses of $3.5\times 10^{19}$ and $2\times 10^{24}$ g. We interpret the one-off transit events as collisions between planetesimal remnants and pre-existing circumstellar debris that trigger collisional cascades: short-timescale variability traces dust-producing fragments crossing the star, while slower changes trace the build-up and clearing of an optically thick dusty structure. In contrast, ZTF~J0436+5728 shows a coherent 5.910-h period, consistent with a rocky body shedding material near the tidal-disruption radius.
发表机构
- Institute of Science and Technology Austria（奥地利科学技术研究所）
- Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安顿·潘内科克天文学研究所）
- Cahill Center for Astrophysics, California Institute of Technology（加州理工学院凯斯天体物理中心）
- Department of Astronomy & Institute for Astrophysical Research, Boston University（波士顿大学天文系与天体物理研究所）
- Center for Astrophysics, Harvard & Smithsonian（哈佛-史密森尼天体物理中心）
- Instituto de Astrofisica de Canarias（加那利天体物理学研究所）
- Department of Physics, University of Warwick（华威大学物理系）
- Columbia University（哥伦比亚大学）
机构由 AI 辅助整理，请以论文原文为准。
