{"title":"彗星彗尾喷流的几何模型","authors":"","doi":"10.1016/j.icarus.2024.116300","DOIUrl":null,"url":null,"abstract":"<div><p>Cometary comae frequently exhibit various formations such as jets, fans, and shells, which can provide crucial insights into the nuclear rotation parameters and the presence of active regions on cometary nuclei. To accurately interpret the visible shape of these jets, a geometric model has been developed. This model considers several factors, including the position of the comet nucleus’s axis of rotation, the location of active areas on the comet’s surface, the angular size of the emission cone, and the relative positions of the Earth, the Sun, and the comet. Utilizing this model, it is possible to track the evolution of the jets over extended periods, enhancing the precision of the model parameters estimation through its simplification. Application of the geometrical model is demonstrated in determining the rotational parameters of the nucleus of comet C/2017 K2 (PANSTARRS). The coordinates for the positive pole of the rotational axis of the comet’s nucleus are: right ascension <span><math><mrow><mi>α</mi><mo>=</mo><mn>70</mn><mo>°</mo><mo>±</mo><mn>15</mn><mo>°</mo></mrow></math></span>, declination <span><math><mrow><mi>δ</mi><mo>=</mo><mo>−</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>, and the rotation period is 166.50 ± 0.02 h. The shape of the jet feature is consistent with an active area located at that latitude <span><math><mrow><mi>ϕ</mi><mo>=</mo><mo>+</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>. The mean velocity of the dust particles is calculated to be 0.23 ± 0.03 km/s.</p></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Geometrical model of jets in cometary comae\",\"authors\":\"\",\"doi\":\"10.1016/j.icarus.2024.116300\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Cometary comae frequently exhibit various formations such as jets, fans, and shells, which can provide crucial insights into the nuclear rotation parameters and the presence of active regions on cometary nuclei. To accurately interpret the visible shape of these jets, a geometric model has been developed. This model considers several factors, including the position of the comet nucleus’s axis of rotation, the location of active areas on the comet’s surface, the angular size of the emission cone, and the relative positions of the Earth, the Sun, and the comet. Utilizing this model, it is possible to track the evolution of the jets over extended periods, enhancing the precision of the model parameters estimation through its simplification. Application of the geometrical model is demonstrated in determining the rotational parameters of the nucleus of comet C/2017 K2 (PANSTARRS). The coordinates for the positive pole of the rotational axis of the comet’s nucleus are: right ascension <span><math><mrow><mi>α</mi><mo>=</mo><mn>70</mn><mo>°</mo><mo>±</mo><mn>15</mn><mo>°</mo></mrow></math></span>, declination <span><math><mrow><mi>δ</mi><mo>=</mo><mo>−</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>, and the rotation period is 166.50 ± 0.02 h. The shape of the jet feature is consistent with an active area located at that latitude <span><math><mrow><mi>ϕ</mi><mo>=</mo><mo>+</mo><mn>45</mn><mo>°</mo><mo>±</mo><mn>6</mn><mo>°</mo></mrow></math></span>. The mean velocity of the dust particles is calculated to be 0.23 ± 0.03 km/s.</p></div>\",\"PeriodicalId\":13199,\"journal\":{\"name\":\"Icarus\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-09-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Icarus\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0019103524003609\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Icarus","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0019103524003609","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Cometary comae frequently exhibit various formations such as jets, fans, and shells, which can provide crucial insights into the nuclear rotation parameters and the presence of active regions on cometary nuclei. To accurately interpret the visible shape of these jets, a geometric model has been developed. This model considers several factors, including the position of the comet nucleus’s axis of rotation, the location of active areas on the comet’s surface, the angular size of the emission cone, and the relative positions of the Earth, the Sun, and the comet. Utilizing this model, it is possible to track the evolution of the jets over extended periods, enhancing the precision of the model parameters estimation through its simplification. Application of the geometrical model is demonstrated in determining the rotational parameters of the nucleus of comet C/2017 K2 (PANSTARRS). The coordinates for the positive pole of the rotational axis of the comet’s nucleus are: right ascension , declination , and the rotation period is 166.50 ± 0.02 h. The shape of the jet feature is consistent with an active area located at that latitude . The mean velocity of the dust particles is calculated to be 0.23 ± 0.03 km/s.
期刊介绍:
Icarus is devoted to the publication of original contributions in the field of Solar System studies. Manuscripts reporting the results of new research - observational, experimental, or theoretical - concerning the astronomy, geology, meteorology, physics, chemistry, biology, and other scientific aspects of our Solar System or extrasolar systems are welcome. The journal generally does not publish papers devoted exclusively to the Sun, the Earth, celestial mechanics, meteoritics, or astrophysics. Icarus does not publish papers that provide "improved" versions of Bode''s law, or other numerical relations, without a sound physical basis. Icarus does not publish meeting announcements or general notices. Reviews, historical papers, and manuscripts describing spacecraft instrumentation may be considered, but only with prior approval of the editor. An entire issue of the journal is occasionally devoted to a single subject, usually arising from a conference on the same topic. The language of publication is English. American or British usage is accepted, but not a mixture of these.