169P/NEAT
 169P/NEAT on 12 August 2026 at 4:54 UT with a Unistellar 114mm smart telescope. | |
| Discovery | |
|---|---|
| Discovered by | NEAT |
| Discovery date | 15 March 2002 |
| Designations | |
| P/2002 EX12 | |
| Orbital characteristics[1][2] | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Observation arc | 36.15 years |
| Earliest precovery date | 7 March 1989 |
| Number of observations | 1,374 |
| Aphelion | 4.603 AU |
| Perihelion | 0.604 AU |
| Semi-major axis | 2.604 AU |
| Eccentricity | 0.76796 |
| Orbital period | 4.201 years |
| Inclination | 11.285° |
| 176.04° | |
| Argument of periapsis | 218.13° |
| Mean anomaly | 288.59° |
| Last perihelion | 21 September 2026 |
| Next perihelion | 1 December 2030[3] |
| TJupiter | 2.888 |
| Earth MOID | 0.142 AU |
| Jupiter MOID | 0.978 AU |
| Physical characteristics[4] | |
Mean radius | 2.5Â km (1.6Â mi) |
| 8.369 hours | |
| Comet total magnitude (M1) | 16.8 |
169P/NEAT is a periodic comet in the Solar System roughly 5 km in diameter with a 4.2 year orbit around the Sun. It is the parent body of the alpha Capricornids meteor shower in late July that may become a major shower around the 23rd century. 169/NEAT may be related to comet P/2003 T12 (SOHO).[5][6]
As of mid-September 2026, the comet was around apparent magnitude 11.[7][8] On 2 August 2026 the comet passed less than 1 degree from M13, the Hercules cluster. The closest approach to Earth was on 11 August 2026 at a distance of 0.167 AU (25.0 million km).[7] At perihelion on 21 September 2026 the solar elongation was 34 degrees at a magnitude of approximately 11.[7]
| Date & time of closest approach |
Earth distance (AU) |
Sun distance (AU) |
Velocity wrt Earth (km/s) |
Velocity wrt Sun (km/s) |
Uncertainty region (3-sigma) |
Solar elongation |
Reference |
|---|---|---|---|---|---|---|---|
| 2026-Aug-11 19:34 | 0.167 AU (25.0 million km; 15.5 million mi) | 0.953 AU (142.6 million km; 88.6 million mi) | 19.9 | 39.0 | ± 33 km | 64° | Horizons |
Physical characteristics
[edit]169P is a low activity comet roughly about 5.0Â km (3.1Â mi) in diameter,[4][9] with a rotation period lasting about 8.4 hours.[4] It could have originated from the main asteroid belt.[6]
Orbit
[edit]It came to perihelion (closest approach to the Sun) on 9 July 2022[2] and on 13 July 2022 passed 0.1395 AU (20.87 million km) from Venus.[1] On 11 August 2026, it passed 0.1672 AU (25.01 million km) from Earth and reached perihelion on 21 September 2026. It will next come to perihelion on 1 December 2030.[3]
169P has a similar stable orbit with the smaller body P/2003 T12 (SOHO), both avoiding close encounters with Jupiter. It is possible that both comets likely fragmented from a parent body a bit over 2,000 years ago.[6][9] A further fragmentation even about 4,500 to 5,000 years ago could have produced the meteors of the alpha Capricornids meteor shower. The total estimated mass of the meteors is similar to that of the surviving comet.[10]
References
[edit]- 1 2 3 "169P/NEAT â JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 22 June 2022.
- 1 2 "169P/NEAT Orbit". Minor Planet Center. Retrieved 2 June 2014.
- 1 2 "Horizons Batch for 169P/NEAT on 2030-Dec-01" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 21 September 2026. (JPL#165 Soln.date: 2026-Sep-21)
- 1 2 3 B. E. A. Mueller; N. H. Samarasinha (2018). "Further Investigation of Changes in Cometary Rotation". The Astronomical Journal. 156 (3): 107â114. arXiv:1806.11158. Bibcode:2018AJ....156..107M. doi:10.3847/1538-3881/aad0a1. (Table #3)
- â "169P NEAT and P/2003 T12 - 300 years ago". Archived from the original on 31 May 2014. Retrieved 31 May 2014.
- 1 2 3 S. R. Alvarez; A. S. Oyarzabal (2024). "Comet P/2003 T12 (SOHO): A possible fragment of comet 169P/NEAT?". Planetary and Space Science. 246 105902. doi:10.1016/j.pss.2024.105902.
- 1 2 3 G. van Buitenen. "169P/NEAT". astro.vanbuitenen.nl. Retrieved 14 April 2026.
- â "COBS Observation list: 169P". Crni Vrh Observatory. Retrieved 3 August 2026. Comet 169P/NEAT Lightcurve
- 1 2 A. Sosa; J. A. FernĂĄndez; A. Fitzsimmons (2015). "Comets 169P/NEAT and P/2003 T12 (SOHO): Two possible fragments of a common ancestor?". American Astronomical Society. 29. Bibcode:2015IAUGA..2255583S.
- â P. Jenniskens; J. Vaubaillon (2010). "Minor Planet 2002 EX12 (169P/NEAT) and the Alpha Capricornid Shower". The Astronomical Journal. 139 (5): 1822â1830. doi:10.1088/0004-6256/139/5/1822.
External links
[edit]- 169P/NEAT at the JPL Small-Body Database
- 169P on Seiichi Yoshida's comet list
- 169P/NEAT at Gideon van Buitenen's website
- 169P at COBS
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