Comet Hale–Bopp
Comet Hale–Bopp, shortly after passing perihelion on April 4, 1997 | |
| Discovery | |
|---|---|
| Discovered by | |
| Discovery site | United States |
| Discovery date | July 23, 1995 |
| Designations | |
| Pronunciation | /ˌheɪl ˈbɒp/ |
| CJ95O010 | |
| Orbital characteristics | |
| Epoch | 15 September 2022 (JD 2459837.5) |
| Observation arc | 29.2 years |
| Number of observations | 66 |
| Aphelion | 354 AU |
| Perihelion | 0.914 AU |
| Semi-major axis | 177.43 AU |
| Eccentricity | 0.99498 |
| Orbital period | (Barycentric 2,399 yr) 2,364–2,520 yr |
| Inclination | 89.287° |
| 282.73° | |
| Argument of periapsis | 130.41° |
| Last perihelion |
|
| Next perihelion | ~4383–4387 AD |
| TJupiter | 0.044 |
| Earth MOID | 0.088 AU |
| Jupiter MOID | 0.079 AU |
| Physical characteristics | |
| Dimensions | 40–80 km (25–50 mi) |
Mean diameter | 60 km (37 mi) |
Mean radius | 30 km (19 mi) |
| 11.35±0.04 hours | |
| 0.01–0.07 | |
| Comet total magnitude (M1) | –1.3 |
| –1.8 (1997 apparition) | |
Comet Hale–Bopp (formally designated C/1995 O1) is a long-period comet that was one of the most widely observed of the 20th century and one of the brightest seen for many decades.
Alan Hale and Thomas Bopp discovered Comet Hale–Bopp separately on July 23, 1995, before it became visible to the naked eye. It is difficult to predict the maximum brightness of new comets with any degree of certainty, but Hale–Bopp exceeded most predictions when it passed perihelion on April 1, 1997, reaching about magnitude −1.8. Its massive nucleus size made it visible to the naked eye for a record 18 months. This is twice as long as the Great Comet of 1811, the previous record holder. Accordingly, Hale–Bopp was dubbed the Great Comet of 1997.