标题： 2019年捷克共和国观测到的α单峰流星体的特性 显示英文标题

标题： Properties of Alpha Monocerotid meteors from the observation of the 2019 outburst in the Czech Republic

摘要： 我们在2019年11月22日观察到了预测的Alpha Monocerotid (AMO) 流星雨爆发，使用的是我们现代化的视频和摄影相机。由于爆发持续时间短且强度适中，仅获得了十颗流星的大气轨迹和辐射点，其中七颗包含了速度、亮度和轨道。此外，还捕捉到了一个不完整的视频光谱。发现辐射点和轨道与1995年爆发的相兼容。光谱确认了AMO流星体缺乏钠。与其他任何流星雨不同，发现所有亮度在+4到-2之间且大气轨迹长度最多为40公里的流星的终点高度都分布在恒定的90公里水平上。我们提出Alpha Monocerotids是由一种脱挥发分且脆弱的彗星地壳形成的，该地壳由相对较大的基本颗粒组成。 显示英文摘要

摘要： We observed the predicted outburst of the Alpha Monocerotid (AMO) meteor shower on 2019 November 22 with our modernized video and photographic cameras. Due to the short duration and moderate intensity of the outburst, atmospheric trajectories and radiants were obtained for only ten meteors, seven of which included velocities, magnitudes, and orbits. In addition, one incomplete video spectrum was captured. The radiants and orbits were found to be compatible with that of the 1995 outburst. The spectrum confirmed that AMO meteoroids are deficient in sodium. Unlike any other meteor shower, meteor end heights were found to be distributed along a constant level of 90 km for all meteors with magnitudes between +4 and -2 and with atmospheric trajectory lengths up to 40 km. We propose that Alpha Monocerotids were formed from a devolatilized and fragile cometary crust composed from relatively large fundamental grains.