42355 Typhon
Hubble Space Telescope image of Typhon and its moon Echidna, taken in 2006 | |
| Discovery | |
|---|---|
| Discovered by | NEAT |
| Discovery date | 5 February 2002 |
| Designations | |
| (42355) Typhon | |
| Pronunciation | /ˈtaɪfɒn/ |
Named after | Τυφών Typhōn |
| 2002 CR46 | |
| SDO Centaur | |
| Adjectives | Typhonian /taɪˈfoʊniən/ |
| Symbol | (rare) |
| Orbital characteristics | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 9563 days (26.18 yr) |
| Aphelion | 58.982252 AU (8.8236193 Tm) |
| Perihelion | 17.545721 AU (2.6248025 Tm) |
| 38.263987 AU (5.7242110 Tm) | |
| Eccentricity | 0.5414560 |
| 236.70 yr (86453.7 d) | |
| 14.61898075° | |
| 0° 0m 14.991s / day | |
| Inclination | 2.4252078° |
| 351.9098598° | |
| 159.3215723° | |
| Known satellites | 1 (Echidna) |
| TJupiter | 4.692 |
| Physical characteristics | |
| 138±9 km 162±7 km | |
| Mass | ≈9.082×1017 kg |
Mean density | 0.66+0.09 −0.08 g/cm3 |
| 9.67 h (0.403 d) | |
| 0.044±0.003 0.10±0.02 | |
| B−V=0.74±0.02 V−R=0.52±0.01 | |
| 7.5 | |
42355 Typhon (/ˈtaɪfɒn/; provisional designation 2002 CR46) is a scattered disc object that was discovered on February 5, 2002, by the NEAT program. It measures 162±7 km in diameter, and is named after Typhon, a monster in Greek mythology.
Typhon is the first known binary centaur, using an extended definition of a centaur as an object on a non-resonant (unstable) orbit with the perihelion inside the orbit of Neptune.
Planetary symbols are no longer much used in astronomy, so Typhon never received a symbol in the astronomical literature. There is no standard symbol for Typhon used by astrologers either. A hurricane symbol () has been used, which might be identified with U+1F300 🌀︎ CYCLONE (U+FE0E ︎ VARIATION SELECTOR-15 is used to make the character display as text).