C/1980 E1 (Bowell)
Hyperbolic path with annual motion
Discovered byEdward L. G. Bowell
Discovery date11 February 1980
C/1980 E1
Orbital characteristics[2]
EpochJD 2444972.5
(3 January 1982)
Observation arc6.88 years
Number of
Aphelion~75000 AU (inbound)[1]
Perihelion3.3639 AU[2]
Eccentricity1.057[2] (hyperbolic trajectory)
1.053 (epoch 1984+)[1]
Orbital period~7.1 million years (epoch 1950)[1]
Ejection (epoch 1977+)[1]
Argument of
Last perihelion12 March 1982[2]
Physical characteristics
Dimensions> 1 km

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 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]

C/1980 E1 distance and velocity compared to the Sun with a 300 year stepsize[8]
Date Sun distance
wrt Sun
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.

Eccentricity vs time
Animation of C/1980 E1's orbit
  C/1980 E1 (Bowell) ·   Sun ·  ·   Earth ·   Mars ·   Jupiter ·   Saturn

See also


  1. ^ v = 42.1219 1/r − 0.5/a, where r is the distance from the Sun, and a is the major semi-axis. At epoch 2500, C/1980 E1 will have a barycentric semi-major axis of −62.44.


  1. ^ a b c d e f g Horizons output. "Barycentric Osculating Orbital Elements for Comet C/1980 E1 (Bowell)". Solution using the Solar System Barycenter. Ephemeris Type:Elements and Center:@0 (To be outside planetary region, inbound epoch 1950 and outbound epoch 2050)
  2. ^ a b c d e f "JPL Small-Body Database Browser: C/1980 E1 (Bowell)" (last observation: 1986-12-30). Retrieved 26 September 2015.
  3. ^ de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (1 November 2017). "Pole, Pericenter, and Nodes of the Interstellar Minor Body A/2017 U1". Research Notes of the AAS. 1 (1): 9 (2 pages). arXiv:1711.00445. Bibcode:2017RNAAS...1....5D. doi:10.3847/2515-5172/aa96b4. S2CID 119537175.
  4. ^ de León, Julia; Licandro, Javier; Serra-Ricart, Miquel; Cabrera-Lavers, Antonio; Font Serra, Joan; Scarpa, Riccardo; de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (19 September 2019). "Interstellar Visitors: A Physical Characterization of Comet C/2019 Q4 (Borisov) with OSIRIS at the 10.4 m GTC". Research Notes of the AAS. 3 (9): 131. Bibcode:2019RNAAS...3..131D. doi:10.3847/2515-5172/ab449c. ISSN 2515-5172. S2CID 204193392.
  5. ^ "C/1980 E1 (Bowell) Orbit at the Minor Planet Center". Retrieved 28 September 2015.
  6. ^ "Horizons Batch: Passing Neptune's orbit at 30.1 AU from the Sun" (Solar escape velocity at 30.1 AU is about 7.67 km/s). JPL Horizons.
  7. ^ Yeomans, Donald K.; Chamberlin, Alan B. "Horizons Ephemeris". JPL Solar System Dynamics. Retrieved 22 February 2011.
  8. ^ "Horizons Batch for Distance and Velocity using a 300 year stepsize". JPL Horizons. Retrieved 3 February 2023.
  9. ^ Ahearn, Michael F.; Schleicher, D. G.; Millis, R. L.; Feldman, P. D.; Thompson, D. T. (1984). "Comet Bowell 1980b". Astronomical Journal. 89: 579–591. Bibcode:1984AJ.....89..579A. doi:10.1086/113552.