C/2017 U7 (PanSTARRS)
The orbit of C/2017 U7 (PanSTARRS) | |
| Discovery | |
|---|---|
| Discovered by | Pan-STARRS |
| Discovery site | Haleakala Observatory |
| Discovery date | 29 October 2017 |
| Designations | |
| C/2017 U7, A/2017 U7 | |
| P10EwQh | |
| Orbital characteristics | |
| Epoch | 8 January 2020 (JD 2458856.5) |
| Observation arc | 176 days |
| Earliest precovery date | 18 August 2017 |
| Perihelion | 6.418 AU |
| Semi-major axis | ~9,500 AU (inbound) |
| Eccentricity | 0.99932 (inbound) 1.00012 (outbound) |
| Orbital period | ~920,000 years (inbound) |
| Inclination | 142.64° |
| 276.23° | |
| Argument of periapsis | 326.07° |
| Last perihelion | 11 September 2019 |
| Earth MOID | 5.467 AU |
| Jupiter MOID | 1.634 AU |
| Physical characteristics | |
Mean radius | 22.5 km (14.0 mi) |
| 0.04 (assumed) | |
| Comet total magnitude (M1) | 6.1 |
| 15.0 (2020 apparition) | |
C/2017 U7 (PanSTARRS) is a hyperbolic comet (previously classified as A/2017 U7, a hyperbolic asteroid), first observed on 29 October 2017 by astronomers of the Pan-STARRS facility at the Haleakala Observatory, Hawaii, United States when the object was 7.8 AU (1.2 billion km) from the Sun. Despite being discovered only 10 days after interstellar asteroid 1I/'Oumuamua, it was not announced until March 2018 (along with C/2018 C2 (Lemmon), which was believed to be another hyperbolic asteroid at the time) as its orbit is not strongly hyperbolic beyond most Oort Cloud comets. As of August 2018, there is only 1 hyperbolic asteroid known, 1I/ʻOumuamua, but hundreds of hyperbolic comets are found.