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arXiv 1209.5980astro-ph.EP
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仙女座流星雨的回归

The return of the Andromedids meteor shower

Paul A. Wiegert, Peter G. Brown, Robert J. Weryk, Daniel K. Wong

摘要:

仙女座流星雨在1872年和1885年经历了壮观的爆发,每小时产生数千颗可见的流星,在当时的中国记录中被描述为“星星像雨一样落下”。流星雨起源于3D/Biela彗星,它在19世纪中期的解体与爆发有关,但自19世纪后期以来,流星雨一直很弱或不存在。这场阵雨于2011年12月再次出现,天顶每小时风速约为50,是一百多年来最强的一次。加拿大流星轨道雷达探测到大约122个可能的仙女座轨道。2011年12月3日至5日期间发生了阵雨爆发。位于RA + $18\degree$和Dec + $56\degree$的辐射点是典型的19世纪早期的“经典”仙女座流星雨,其辐射点实际上是仙后座。轨道要素表明,所涉及的物质是在1846年之前3D/Biela解体之前释放的。2011年观测到的流星雨地心速度较慢($^{-1}$为16公里/秒),由小颗粒组成:雷达测得的平均质量为$\sim5 \times 10^{-7}$千克,对应半径为0.5毫米,体积密度为$^3$/米。母彗星的数值模拟表明,2011年仙女座流星雨返回的流星体主要是在3D/Biela 1649年的近日点通过期间喷出的。轨道特征、辐射、时间以及小束中没有大粒子都与模拟结果一致。根据我们的数值模型,预测了2000-2047年的其他阵雨。我们注意到,2011年返回的细节原则上可以用来更好地约束彗星在1772年首次记录返回之前的3D/Biela轨道。

英文摘要:

The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as `stars fell like rain' in Chinese records of the time. The shower originates from comet 3D/Biela whose disintegration in the mid-1800's is linked to the outbursts, but the shower has been weak or absent since the late 19th Century. This shower returned in December 2011 with a zenithal hourly rate of approximately 50, the strongest return in over a hundred years. Some 122 probable Andromedid orbits were detected by the Canadian Meteor Orbit Radar. The shower outburst occurred during 2011 Dec 3-5. The radiant at RA +$18\degree$ and Dec +$56\degree$ is typical of the `classical' Andromedids of the early 1800's, whose radiant was actually in Cassiopeia. The orbital elements indicate that the material involved was released before 3D/Biela's breakup prior to 1846. The observed shower in 2011 had a slow geocentric speed (16 km s$^{-1}$) and was comprised of small particles: the mean measured mass from the radar is $\sim5 \times 10^{-7}$ kg corresponding to radii of 0.5 mm at a bulk density of 1000 kg/m$^3$. Numerical simulations of the parent comet indicate that the meteoroids of the 2011 return of the Andromedids shower were primarily ejected during 3D/Biela's 1649 perihelion passage. The orbital characteristics, radiant, timing as well as the absence of large particles in the streamlet are all consistent with simulations. Predictions are made regarding other appearances of the shower in the years 2000-2047 based on our numerical model. We note that the details of the 2011 return can, in principle, be used to better constrain the orbit of 3D/Biela prior to the comets first recorded return in 1772.

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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