Comet 19/P Borrelly in 2021–22: Change in the spin axis orientation versus previous apparitions
Comet 19/P Borrelly in 2021–22: Change in the spin axis orientation versus previous apparitions
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2021-22 年的 19/P Borrelly 彗星：自转轴方向与之前彗星相比的变化
DOI：
10.1016/j.icarus.2023.115451
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发表时间：
2023
期刊：
影响因子：
3.2
通讯作者：
J. Bosch
中科院分区：
文献类型：
--
作者：
V. Oldani;F. Manzini;P. Ochner;Andrea Reguitti;L. Bedin;R. Behrend;J. Bosch
19P/Borrelly 彗星的特征是存在几乎与其旋转轴对齐的突出极地喷流。因此，过去几位作者使用极地喷流模型来确定彗星自转轴的方向。为了验证 2021-22 年显现期间的自转轴是否处于已发布的极坐标的预期位置，精确测量了极地喷流的位置角 (PA)，得出自转轴方向为 RA = 206.1° 和 Dec = -5.0°。这些坐标与其他作者在之前的显灵期间发布的所有坐标都不同。将其他作者在早期显现期间（1911-1932年和1994-2008年）对喷流的PA进行的测量与根据新极坐标计算的假设PA进行比较，显示出显着差异，从而证实了彗星的轴当前指向不同的位置。由于缺乏 2015 年最后一次经过近日点的合适图像，无法澄清 2021-22 年观测到的自转轴移动是否发生在该轨道期间，还是缓慢、长期漂移或进动的结果。
Comet 19P/Borrelly is characterized by the presence of a prominent polar jet that is nearly aligned with its rotation axis. The polar jet model has therefore been used in the past by several authors to determine the orientation of the comet's spin axis. To verify whether the spin axis during the 2021–22 apparition was in the expected positions according to the published pole coordinates, the position angles (PA) of the polar jet were accurately measured, resulting in a spin axis orientation at RA = 206.1° and Dec = −5.0°. These coordinates are different from all those published by other authors during previous apparitions. The comparison of the measurements of the PAs of the jet made by other authors during earlier apparitions (1911–1932 and from 1994 to 2008) with the hypothetical PAs calculated according to the new pole coordinates showed significant differences, thus confirming that the comet's axis is currently pointing to a different position. The lack of suitable images of the last perihelion passage of 2015 does not allow to clarify whether the shift of the spin axis observed in 2021–22 occurred during this orbit or is the result of a slow, secular drift or of a precession.