Comet Holmes
Outburst of Comet Holmes photographed by Iván Éder on 4 November 2007 | |
| Discovery | |
|---|---|
| Discovered by | Edwin Holmes |
| Discovery date | 6 November 1892 |
| Designations | |
| P/1892 V1, P/1899 L1 P/1964 O1 | |
| |
| Orbital characteristics | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Aphelion | 5.194 AU |
| Perihelion | 2.090 AU |
| Semi-major axis | 3.642 AU |
| Eccentricity | 0.42616 |
| Orbital period | 6.951 years |
| Inclination | 19.005° |
| 326.60° | |
| Argument of periapsis | 24.603° |
| Mean anomaly | 246.31° |
| Last perihelion | 19 February 2021 |
| Next perihelion | 31 January 2028 |
| TJupiter | 2.859 |
| Earth MOID | 1.073 AU |
| Jupiter MOID | 0.481 AU |
| Physical characteristics | |
Mean radius | 1.71 km (1.06 mi) |
Mean density | 0.09±0.02 g/cm3 |
| |
| Comet total magnitude (M1) | 9.4 |
| Comet nuclear magnitude (M2) | 13.8 |
Comet Holmes /ˈhoʊmz/ (official designation: 17P/Holmes) is a periodic comet in the Solar System, discovered by the British amateur astronomer Edwin Holmes on November 6, 1892. Although normally a very faint object, Holmes became notable during its October 2007 return when it temporarily brightened by a factor of a million, in what was the largest known outburst by a comet, and became visible to the naked eye. It also briefly became the largest object in the Solar System, as its coma (the thin dissipating dust ball around the comet) expanded to a diameter greater than that of the Sun (although its mass remained minuscule). Between 1857–2106 perihelion remains between 2.05–2.36 AU.