2I/Borisov
Interstellar comet · 2019 Q4
2I/Borisov combined a strongly unbound interstellar trajectory with an unmistakable cometary coma after its discovery in August 2019. Hubble imaged dust around an unresolved nucleus, while Hubble and ALMA measured a high carbon-monoxide abundance relative to water under the observed conditions. That chemistry points towards a cold formation history without identifying a unique parent star. Changes observed in 2020 also suggested fragmentation during the solar encounter.
Understand this world
What made Borisov an interstellar comet?Borisov combined an unbound orbit with unmistakable cometary activity. Explore what Hubble and ALMA measured and what its carbon monoxide reveals about formation. · 3 minMeasurements
- Effective diameter
- Not available
- Semimajor axis
- -0.851 AU
- Orbital period
- Not available
Orbit, physical values and uncertainties
- eccentricity
- 3.356475782676596 ± 1.9039E-5
- semi-major axis
- -.8514922551937886 au ± 5.8802E-6
- perihelion distance
- 2.006520878500843 au ± 3.2904E-6
- inclination; angle with respect to x-y ecliptic plane
- 44.05264247909138 deg ± 1.6673E-5
- longitude of the ascending node
- 308.1477292269942 deg ± 4.5021E-5
- argument of perihelion
- 209.1236864378081 deg ± .00011012
- mean anomaly
- 34.4294703072178 deg ± .00043173
- time of perihelion passage
- 2458826.052845906059 TDB ± .00014206
- sidereal orbital period
- Not available
- mean motion
- 1.254391263639903 deg/d ± 1.2994E-5
- aphelion distance
- Not available
- comet total magnitude
- 13.8 ± 0.8
- comet total magnitude slope
- 4.5
Published JPL orbital elements describe their stated epoch; they are not current positions. Small-body diameters can be effective/model-dependent sizes, not spherical shapes. Missing measurements remain unavailable. Pluto’s diameter uses the New Horizons reference rather than an empty SBDB field. Orbital epoch: JD 2458853.5 TDB.
Object reference ↗Missions & milestones
0 launches · 0 connected events
These are target-related flights and every connected programme record in the production catalogue. A connected event may concern another stage or target of the same journey. Launch outcome does not establish arrival or current operation.
No verified target-related flight is linked in the production catalogue.
Complete source cohort: 9,390 records.