167P/CINEOS

167P/CINEOS
Discovery
Discovered by	CINEOS
Discovery date	August 10, 2004
Designations
MPC designation	P/2004 PY42
Orbital characteristics
Epoch	November 21, 2025 (JD 2461000.5)
Observation arc	9.35 years
Earliest precovery date	June 12, 2002
Number of; observations	99
Aphelion	20.598 AU
Perihelion	11.894 AU
Semi-major axis	16.246 AU
Eccentricity	0.26787
Orbital period	65.483 years
Max. orbital speed	9.8 km/s
Min. orbital speed	5.6 km/s
Inclination	19.073°
Longitude of; ascending node	295.84°
Argument of; periapsis	344.33°
Mean anomaly	135.64°
Last perihelion	April 24, 2001
Next perihelion	March 18, 2066; March 23, 2066;
TJupiter	3.527
Earth MOID	10.771 AU
Jupiter MOID	6.604 AU
Physical characteristics
Dimensions	66.17 ± 22.9 km (41.12 ± 14.23 mi)
Geometric albedo	0.053±0.019
Spectral type	(B–V) = 0.80±0.04; (V–R) = 0.57±0.03; (R–I) = 0.45±0.03; (B–R) = 1.29±0.03;
Comet nuclear; magnitude (M2)	9.7

167P/CINEOS, also known as P/2004 PY₄₂, is a large periodic comet and active, grey centaur, approximately 66 kilometers (41 miles) in diameter, orbiting the Sun outside the orbit of Saturn. It was discovered on August 10, 2004, by astronomers with the CINEOS survey at Gran Sasso in Italy. It is one of only a handful known Chiron-type comets.

The comet nucleus (~66 km) is roughly half the size of C/2014 UN271 (Bernardinelli–Bernstein) and it has a similar perihelion point just outside the orbit of Saturn.

Large comets with perihelion near Saturn's orbit at 10 AU
Comet	Nucleus diameter	Perihelion (Sun approach)	Perihelion velocity
95P/Chiron	215 km	8.5 AU	12.0 km/s
C/2014 UN271 (Bernardinelli–Bernstein)	120 km	10.95 AU	12.7 km/s
167P/CINEOS	66 km	11.77 AU	9.8 km/s^[4]

Observational history

Due to its high Jupiter tisserand of 3.5, and a semi-major axis larger than that of Jupiter, 167P/CINEOS is classified as a Chiron-type comet, named after the groups namesake, 2060 Chiron or 95P/Chiron, designated as both minor planet and comet.^[2]

167P/CINEOS was first reported as a minor planet, designated 2004 PY₄₂, but was found to have a very faint asymmetric cometary coma.^[1] Contrary to Chiron, which is the prototype object for the dynamical group of centaurs, 167P/CINEOS has no "dual status" as comet and minor planet, and demonstrates the inconsistencies in applying the current rules for designating small Solar System bodies.^[9] 167P/CINEOS not only has orbital parameters similar to those of Chiron, but also a low B–R magnitude of 1.29±0.03, which places it into the group grey centaurs.^[8]

In June 2039, 167P/CINEOS will pass 1.64 AU from Uranus.^[2]

Notes

↑ Observation arc from the Minor Planet Center database covering dates from June 12, 2002 until October 19, 2011.
↑ Minimum orbital speed attained at its next aphelion on November 30, 2033.

References

1 2 W. Romanishin; S. C. Tegler; A. Boattini; F. de Luise; A. di Paola (June 17, 2005). D. W. Green (ed.). "Comet C/2004 PY₄₂ (CINEOS)". IAU Circular (8545): 1. Bibcode:2005IAUC.8545....1R. ISSN 0081-0304.
1 2 3 4 "167P/CINEOS – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved July 12, 2012.
↑ "167P/CINEOS Orbit". Minor Planet Center. Retrieved June 18, 2014.
1 2 3 "Horizons Batch for 167P/CINEOS on 2066-Mar-18" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Archived from the original on June 24, 2022. Retrieved June 24, 2022. (JPL#22 Soln.date: 2021-Apr-15)
↑ Syuichi Nakano (June 18, 2005). "167P/CINEOS (2004 PY42) (NK 1185)". OAA Computing and Minor Planet Sections. Retrieved February 20, 2012.
1 2 J. M. Bauer; T. Grav; E. Blauvelt; et al. (2013). "Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations". The Astrophysical Journal. 773 (1): 22–33. arXiv:1306.1862. Bibcode:2013ApJ...773...22B. doi:10.1088/0004-637X/773/1/22.
1 2 3 D. C. Jewitt (2015). "Color Systematics of Comets and Related Bodies". The Astronomical Journal. 150 (6): 201–219. arXiv:1510.07069. Bibcode:2015AJ....150..201J. doi:10.1088/0004-6256/150/6/201.
1 2 S. C. Tegler; W. Romanishin; G. J. Consolmagno (2016). "Two Color Populations of Kuiper Belt and Centaur Objects and the Smaller Orbital Inclinations of Red Centaur Objects". The Astronomical Journal. 152 (6): 210–223. Bibcode:2016AJ....152..210T. doi:10.3847/0004-6256/152/6/210. ISSN 0004-6256.
↑ D. W. Green (June 27, 2005). "Comets 165P/2000 B4, 166P/2001 T4, and 167P/2004 PY₄₂". IAU Circular (8552): 2. Bibcode:2005IAUC.8552....2G. ISSN 0081-0304.

External links

167P/CINEOS at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters
167P/CINEOS at the Minor Planet Center database
167P/CINEOS at Seiichi Yoshida's website

Numbered comets

Previous
166P/NEAT

167P/CINEOS

Next
168P/Hergenrother

[obs_arc-4] Observation arc from the Minor Planet Center database covering dates from June 12, 2002 until October 19, 2011.

[min_orb_vel-6] Minimum orbital speed attained at its next aphelion on November 30, 2033.

[IAUC_8545-1] 1 2 W. Romanishin; S. C. Tegler; A. Boattini; F. de Luise; A. di Paola (June 17, 2005). D. W. Green (ed.). "Comet C/2004 PY₄₂ (CINEOS)". IAU Circular (8545): 1. Bibcode:2005IAUC.8545....1R. ISSN 0081-0304.

[jpldata-2] 1 2 3 4 "167P/CINEOS – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved July 12, 2012.

[MPC-3] "167P/CINEOS Orbit". Minor Planet Center. Retrieved June 18, 2014.

[Horizons2066-5] 1 2 3 "Horizons Batch for 167P/CINEOS on 2066-Mar-18" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Archived from the original on June 24, 2022. Retrieved June 24, 2022. (JPL#22 Soln.date: 2021-Apr-15)

[NK1185-7] Syuichi Nakano (June 18, 2005). "167P/CINEOS (2004 PY42) (NK 1185)". OAA Computing and Minor Planet Sections. Retrieved February 20, 2012.

[Bauer_2013-8] 1 2 J. M. Bauer; T. Grav; E. Blauvelt; et al. (2013). "Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations". The Astrophysical Journal. 773 (1): 22–33. arXiv:1306.1862. Bibcode:2013ApJ...773...22B. doi:10.1088/0004-637X/773/1/22.

[Jewitt_2015-9] 1 2 3 D. C. Jewitt (2015). "Color Systematics of Comets and Related Bodies". The Astronomical Journal. 150 (6): 201–219. arXiv:1510.07069. Bibcode:2015AJ....150..201J. doi:10.1088/0004-6256/150/6/201.

[Tegler_2016-10] 1 2 S. C. Tegler; W. Romanishin; G. J. Consolmagno (2016). "Two Color Populations of Kuiper Belt and Centaur Objects and the Smaller Orbital Inclinations of Red Centaur Objects". The Astronomical Journal. 152 (6): 210–223. Bibcode:2016AJ....152..210T. doi:10.3847/0004-6256/152/6/210. ISSN 0004-6256.

[IAUC_8552-11] D. W. Green (June 27, 2005). "Comets 165P/2000 B4, 166P/2001 T4, and 167P/2004 PY₄₂". IAU Circular (8552): 2. Bibcode:2005IAUC.8552....2G. ISSN 0081-0304.

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