C/2016 U1 (NEOWISE) is a hyperbolic comet discovered 21 October 2016 by NEOWISE, the asteroid-and-comet-hunting portion of the Wide-Field Infrared Survey Explorer (WISE) mission.[1][2][3] The comet brightened to magnitude +6.8[4] and could be observed with binoculars,[5] during the first week of 2017 and it was closest to the Sun on 14 January 2017.[2][6]
 | |
| Discovery | |
|---|---|
| Discovered by | NEOWISE project |
| Discovery site | NEOWISE |
| Discovery date | Friday 21 October 2016[1] |
| Orbital characteristics | |
| Epoch | 2457723.5 (2016-Dec-01.0) TDB[1] Reference: JPL 4 (heliocentric ecliptic J2000)[1] |
| Perihelion | 0.3191 AU[1] |
| Semi-major axis | −3477.5728 AU[1] |
| Eccentricity | 1.0001[1] |
| Inclination | 46.4292 deg[1] |
| 61.4214 deg[1] | |
| Argument of periapsis | 162.7640 deg[1] |
| Last perihelion | 14 January 2017 |
| Next perihelion | ejection |
| Comet total magnitude (M1) | 13.7[1] |
| Comet nuclear magnitude (M2) | 20.0[1] |
It was closest to the Earth on 13 December 2016 at 106,000,000 km (66,000,000 mi)[5] away; it is not considered a threat to Earth.[2] The aphelion of the comet lies at the inner edge of the Oort cloud and it is possible that the 2017 perihelion was not the first and that during a previous perihelion planetary perturbations pushed the comet towards the Oort cloud. Despite its small size, the comet survived perihelion and was observed for days from the SWAN instrument on board SOHO.[7]
Science
Solar system
