kosmos: 2I/Borisov

Evidence: 100 • authority: 72

2I/Borisov, originally designated C/2019 Q4 (Borisov), is the first observed rogue comet and the second observed interstellar interloper, after ʻOumuamua. It was discovered by the amateur astronomer and telescope maker Gennadiy Borisov on 29 August 2019 UTC (30 August local time) in MARGO Observatory. 2I/Borisov has a heliocentric orbital eccentricity of 3.36 and is not bound to the Sun. The comet passed through the ecliptic of the Solar System at the end of October 2019, and made its closest approach to the Sun at just over 2 AU on 8 December 2019. The comet passed closest to Earth on 28 December 2019. In November 2019, astronomers from Yale University said that the comet's tail was 14 tim…

Evidence: 72 • authority: 72

An interstellar object is an astronomical object in interstellar space, not gravitationally bound to a star. The term is used for objects including some asteroids, some comets, and rogue planets, but not stars or stellar remnants. The interstellar objects were likely once bound to a host star and have become unbound since. Different processes can cause planets and smaller objects (planetesimals) to become unbound from their host star. This term is also applied to an object that is on an interstellar trajectory but is temporarily passing close to a star, such as some asteroids and comets (that is, exoasteroids and exocomets). In this case the object may be called an interstellar interloper.…

Evidence: 57 • authority: 88

Unusual polarimetric properties for interstellar comet 2I/Borisov. <p><strong>Introduction</strong></p> <p>Only two interstellar objects have been observed passing through our Solar System to date. The first one, 1I/&amp;#8216;Oumuamua, discovered in 2017 in its post-perihelion phase, showed mostly asteroidal characteristics with some potential evidence of comet-like behaviour, but 2I/Borisov has showed clear evidence of comet activity since its discovery in 2019, prior to its perihelion passage in December of that year. This made it the first confirmed interstellar comet, so naturally many different observations were conducted by astronomers around the world to learn more about the peculia…

Evidence: 57 • authority: 88

Outburst and Splitting of Interstellar Comet 2I/Borisov. We present Hubble Space Telescope observations of a photometric outburst and splitting event in interstellar comet 2I/Borisov. &#160; The outburst, first reported with the comet outbound at 2.8 AU (Drahus et al.~2020), was caused by the expulsion of solid particles having a combined cross-section about 100 sq. km and a mass in 0.1 mm sized particles&#160; 2e7 kg. &#160;The latter corresponds to 1e-4 of the mass of the nucleus, taken as a sphere of radius 500 m. &#160;A transient&#160; double nucleus was observed on UT 2020 March 30 (about three weeks after the outburst), having a cross-section 0.6 sq. km and corresponding dust mass 1e…

Evidence: 51 • authority: 88

Early Observations of the Interstellar Comet 2I/Borisov. 2I/Borisov is the second ever interstellar object (ISO). It is very different from the first ISO ’Oumuamua by showing cometary activities, and hence provides a unique opportunity to study comets that are formed around other stars. Here we present early imaging and spectroscopic follow-ups to study its properties, which reveal an (up to) 5.9 km comet with an extended coma and a short tail. Our spectroscopic data do not reveal any emission lines between 4000–9000 Angstrom; nevertheless, we are able to put an upper limit on the flux of the C2 emission line, suggesting modest cometary activities at early epochs. These properties are simil…

Evidence: 50 • authority: 72

An exocomet, or extrasolar comet, is a comet outside the Solar System, which includes rogue comets and comets that orbit stars other than the Sun. The first exocomets were detected in 1987 around Beta Pictoris, a very young A-type main-sequence star. There are now (as of February 2019) a total of 27 stars around which exocomets have been observed or suspected. The majority of discovered exocometary systems (Beta Pictoris, HR 10, 51 Ophiuchi, HR 2174, HD 85905, 49 Ceti, 5 Vulpeculae, 2 Andromedae, HD 21620, Rho Virginis, HD 145964, HD 172555, Lambda Geminorum, HD 58647, Phi Geminorum, Delta Corvi, HD 109573, Phi Leonis, 35 Aquilae, HD 24966, HD 38056, HD 79469 and HD 225200) are around very…

Evidence: 50 • authority: 88

Spectrosopy of interstellar comet 2I/Borisov with VLT X-Shooter. AbstractDuring the journey through the solar system, interstellar comet 2I/Borisov has been observed spectroscopically by most of the largest telescopes on Earth, enabling comparative studies of its chemical composition versus solar system comets. Already a few weeks after the discovery, the detection of the CN (0-0 band) in the coma has been reported [1]. Subsequent detections of C2 suggested a significant depletion of this molecule [2,3], however, later evolution of C2 placed it close to the typical values [4]. Pre-discovery images of 2I/Borisov showing this object to be active when far away from the sun indicated that its a…

Evidence: 45 • authority: 72

1I/ʻOumuamua is the first confirmed interstellar object detected passing through the Solar System. Formally designated 1I/2017 U1, it was discovered by Canadian physicist Robert Weryk using the Pan-STARRS telescope at Haleakalā Observatory, Hawaii, on 19 October 2017, approximately 40 days after it passed its closest point to the Sun on 9 September. When it was first observed, it was about 33 million km (21 million mi; 0.22 AU) from Earth (about 85 times as far away as the Moon) and already heading away from the Sun. ʻOumuamua is a small object estimated to be between 100 and 1,000 metres (300 and 3,000 ft) long, with its width and thickness both estimated between 35 and 167 metres (115 and…

Evidence: 35 • authority: 88

Comet 2I/Borisov in Comparison with Comets of the Solar System. The brief review summarizes data on the chemical and mineral composition, as well as on the phys ical properties, of the first extrasolar comet 2I/Borisov, obtained from observations that were carried out from September 2019 to the end of March 2020. It is noted that the qualitative chemical composition of the volatile and mineral components comet 2I/Borisov is similar to the composition of comets in the Solar System, but there are differences that indicate the specific conditions for the formation of its nucleus in a circumstellar gas and dust disk. Different release rates of CO and H2O molecules in the vicinity of perihelion…

Evidence: — • authority: 72

C/1980 E1 is a non-periodic comet discovered by Edward L. G. Bowell on 11 February 1980 and which came closest to the Sun (perihelion) in March 1982. It is leaving the Solar System on a hyperbolic trajectory due to a close approach to Jupiter. In the 43 years since its discovery only 3 objects with higher eccentricities have been identified, 1I/ʻOumuamua (1.2), 2I/Borisov (3.35), and 3I/ATLAS (6.15).

Evidence: — • authority: 92

The Comet Interceptor Mission.. Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the ag…

Evidence: — • authority: 80

Clues to Understanding the Microphysics of Dust in the Interstellar Comet C/2019 Q4 (Borisov)