Interstellar comet 2I/Borisov [EPA]

http://arxiv.org/abs/1909.05851


Interstellar comets penetrating through the Solar System were anticipated for decades. The discovery of non-cometary 1I/’Oumuamua by Pan-STARRS was therefore a huge surprise and puzzle. Furthermore, its physical properties turned out to be impossible to reconcile with Solar System objects, which radically changed our view on interstellar minor bodies. Here, we report the identification of a new interstellar object which has an evidently cometary appearance. The body was identified by our data mining code in publicly available astrometric data. The data clearly show significant systematic deviation from what is expected for a parabolic orbit and are consistent with an enormous orbital eccentricity of 3.14 +/- 0.14. Images taken by the William Herschel Telescope and Gemini North telescope show an extended coma and a faint, broad tail – the canonical signatures of cometary activity. The observed g’ and r’ magnitudes are equal to 19.32 +/- 0.02 and 18.69 +/- 0.02, respectively, implying g’-r’ color index of 0.63 +/- 0.03, essentially the same as measured for the native Solar System comets. The discovery of this object indicates that interstellar comets might be common and creates a tremendous opportunity to study the first such object in detail.

Read this paper on arXiv…

P. Guzik, M. Drahus, K. Rusek, et. al.
Fri, 13 Sep 19
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