29P/Schwassmann–Wachmann
29P/Schwassmann–Wachmann imaged by Gemini Observatory in 2021 | |
| Discovery | |
|---|---|
| Discovered by | Arnold Schwassmann Arno Arthur Wachmann |
| Discovery site | Hamburg Observatory |
| Discovery date | November 15, 1927 |
| Designations | |
| P/1902 E1; P/1927 V1 | |
| 1908 IV; 1927 II; 1941 VI; 1957 IV; 1974 II; 1989 XV | |
| Orbital characteristics | |
| Epoch | January 1, 2023 (JD 2459945.5) |
| Observation arc | 13.83 years |
| Earliest precovery date | 4 March 1902 |
| Number of observations | 622 |
| Aphelion | 6.318 AU (30 September 2026) |
| Perihelion | 5.777 AU |
| Semi-major axis | 6.047 AU |
| Eccentricity | 0.0447 |
| Orbital period | 14.87 years |
| Max. orbital speed | 12.7 km/s |
| Inclination | 9.364° |
| 312.39° | |
| Argument of periapsis | 50.913° |
| Last perihelion | March 7, 2019 |
| Next perihelion | February 18, 2035 |
| TJupiter | 2.986 |
| Earth MOID | 4.781 AU |
| Jupiter MOID | 0.792 AU |
| Physical characteristics | |
| Dimensions | 60.4 ± 7.4 km (37.5 ± 4.6 mi) |
| 12.1 ± 1.2 days | |
| 0.033 | |
| Comet total magnitude (M1) | 10.1 |
| ~14 | |
Comet 29P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 1, was discovered on November 15, 1927, by Arnold Schwassmann and Arno Arthur Wachmann at the Hamburg Observatory in Bergedorf, Germany. It is well known for being observable throughout the whole orbit and having frequent outbursts. The most recent outbursts were in May 2025, December 2025, and February 2026. The comet will next come to opposition on 11 March 2026, and then come to aphelion on 30 September 2026. It crossed the celestial equator in late 2025 and is headed further into southern skies until April 2029 when it will have a declination of −31.