论文标题
彗星21p/giacobini-zinner：碳链原型的窄带光度法在多种幻影上耗尽彗星
Comet 21P/Giacobini-Zinner: Narrowband Photometry of the Prototype of Carbon-Chain Depleted Comets at Multiple Apparitions
论文作者
论文摘要
我们获得了跨33年观测值的彗星21p/giacobini-Zinner的广泛窄带光电学光度法。重新降低了1985年的原始数据（Schleicher等人，1987年），并与包括2018/19在内的另外三个幻影的数据一起介绍。与OH和CN相比，有关Giacobini-Zinner化学成分的最初结论保持不变，并且在碳链分子C2和C3和NH中具有4-6倍的耗竭。该彗星继续表现出较大的生产率不对称性，这是时间和中心距离的函数，生产在周围前3-5周达到了峰值。所有物种，包括灰尘，都遵循相同的一般生产率曲线，每个幻影均经过碳含有相似的物种，总是非常相似。但是，OH和NH的细节各不相同，这意味着源区域之间的组成有些不同。从长远来看，围绕圆周和附近的幻影之间只有很小的世俗变化，但是随着彗星从太阳退缩，较大的变化显而易见，暗示了旋转轴的进行性进攻。
We obtained extensive narrowband photoelectric photometry of Comet 21P/Giacobini-Zinner with observations spanning 33 years. The original data from 1985 (Schleicher et al. 1987) were re-reduced and are presented along with data from three additional apparitions including 2018/19. The original conclusion regarding Giacobini-Zinner's chemical composition remains unchanged, with it having a 4-6x depletion in the carbon-chain molecules C2 and C3, and in NH, as compared with both OH and CN. The comet continues to exhibit a large asymmetry in production rates as a function of time and heliocentric distance, with production reaching a peak 3-5 weeks prior to perihelion. All species, including dust, follow the same general production rate curve each apparition, and the carbon-bearing species are always very similar to one another. However, OH and NH each differ in detail from the carbon-bearing species, implying somewhat varied composition between source regions. Longer term, there are only small secular changes among the apparitions before and near perihelion, but larger changes are evident as the comet recedes from the Sun, suggestive of a progressive precession of the rotation axis.
