Hyperbolic path with annual motion | |
Discovery | |
---|---|
Discovered by | Edward L. G. Bowell |
Discovery date | 11 February 1980 |
Designations | |
C/1980 E1 | |
Orbital characteristics[2] | |
Epoch | JD 2444972.5 (3 January 1982) |
Observation arc | 6.88 years |
Number of observations | 187 |
Aphelion | ~75000 AU (inbound)[1] |
Perihelion | 3.3639 AU[2] |
Eccentricity | 1.057[2] (hyperbolic trajectory) 1.053 (epoch 1984+)[1] |
Orbital period | ~7.1 million years (epoch 1950)[1] Ejection (epoch 1977+)[1] |
Inclination | 1.6617° |
114.558° | |
Argument of periapsis | 135.083° |
Last perihelion | 12 March 1982[2] |
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 42 years since its discovery only two objects with higher eccentricities have been identified, 1I/ʻOumuamua (1.2) and 2I/Borisov (3.35).[3][4]
Before entering the inner Solar System for a 1982 perihelion passage, C/1980 E1 had a barycentric (epoch 1950-Jan-01) orbit with an aphelion of 75,000 AU (1.2 ly), and a period of approximately 7.1 million years.[1]
As the comet was approaching on 9 December 1980, it passed within 0.228 AU of Jupiter,[2] which accelerated the comet briefly giving an (epoch 1981-Jan-09) eccentricity of 1.066.[1] The comet came to perihelion on 12 March 1982,[2] when it had a velocity of 23.3 km/s (52,000 mph) with respect to the Sun. Since the epoch of 1977-Mar-04, C/1980 E1 has had a barycentric eccentricity greater than 1,[1] keeping it on a hyperbolic trajectory that will eject it from the Solar System. Objects in hyperbolic orbits have a negative semimajor axis, giving them a positive orbital energy. After leaving the Solar System, C/1980 E1 will have an interstellar velocity () of 3.77 km/s.[a] The Minor Planet Center does not directly list a semimajor axis for this comet.[5]
The escape velocity from the Sun at Neptune's orbit is 7.7 km/s. By June 1995, the comet was passing Neptune's orbit at 30.1 AU from the Sun continuing its ejection trajectory at 8.6 km/s.[6] Since February 2008, the comet has been more than 50 AU from the Sun.[7]
Date | Sun distance (AU) |
Velocity wrt Sun (km/s) |
Uncertainty region (3-sigma) |
---|---|---|---|
1682-03-12 | 248.8 AU (37.22 billion km; 23.13 billion mi) | 2.68 | ± 7 million km |
Perihelion | 3.364 AU (503.2 million km; 312.7 million mi) | 23.3 | ± 1589 km |
2282-03-12 | 337.2 AU (50.44 billion km; 31.34 billion mi) | 4.43 | ± 5 million km |
Emission of OH (hydroxide) was observed pre-perihelion while the comet was nearly 5 AU from the Sun.[9] CN (cyanide) was not detected until the comet was near perihelion. The comet nucleus was estimated to have a radius of several kilometers. The surface crust was probably a few meters thick.