161989 Cacus
Shape model of Cacus from its lightcurve
Discovery[1][2]
Discovered byH.-E. Schuster
Discovery siteLa Silla Obs.
Discovery date8 February 1978
Designations
(161989) Cacus
Named after
Cacus (Roman mythology)[2]
1978 CA
Apollo · NEO · PHA[1]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc38.59 yr (14,096 days)
Aphelion1.3634 AU
Perihelion0.8828 AU
1.1231 AU
Eccentricity0.2140
1.19 yr (435 days)
345.40°
0° 49m 41.16s / day
Inclination26.060°
161.24°
102.16°
Earth MOID0.0152 AU · 5.9 LD
Physical characteristics
Mean diameter
0.64±0.02 km[3]
1.126±0.073 km[4]
1.86 km[5]
1.9 km[6]
3.7538±0.0019 h[6]
3.756 h[7]
3.761 h[5]
3.77±0.11 h[8]
0.09[6]
0.119 (derived)[6]
0.199±0.052[4]
0.46±0.09[3]
Tholen = S[1][6] · Q[9]
B–V = 0.910[1]
U–B = 0.484[1]
16.58[6][7] · 17.1[4] · 17.2[1] · 17.32[5] · 17.43[3]

161989 Cacus (prov. designation: 1978 CA) is a stony asteroid, classified as near-Earth object and a potentially hazardous asteroid of the Apollo group, approximately 1 kilometer in diameter. It was discovered on 8 February 1978, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory in northern Chile.[2] Its orbit is confined between Venus and Mars.

This minor planet was named from Roman mythology, after Cacus, a fire-breathing monster, which was killed by Hercules.[2] The official naming citation was published by the Minor Planet Center on 24 November 2007 (M.P.C. 61270).[10]

Close approaches[1]
Date JPL SBDB
nominal geocentric
distance 		uncertainty
region
(3-sigma)
1941-09-02 2418754 km ± 6 km
2022-09-01 8607710 km ± 21 km[11]

References

  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 161989 Cacus (1978 CA)" (2016-09-12 last obs.). Jet Propulsion Laboratory. Archived from the original on 22 November 2020. Retrieved 13 January 2018.
  2. ^ a b c d "161989 Cacus (1978 CA)". Minor Planet Center. Retrieved 13 January 2018.
  3. ^ a b c Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
  4. ^ a b c Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 35447010.
  5. ^ a b c Degewij, J.; Lebofsky, L.; Lebofsky, M. (March 1978). "1978 CA and 1978 DA". IAU Circ. 3193 (3193): 1. Bibcode:1978IAUC.3193....1D. Retrieved 13 January 2018.
  6. ^ a b c d e f "LCDB Data for (161989) Cacus". Asteroid Lightcurve Database (LCDB). Retrieved 13 January 2018.
  7. ^ a b Schuster, H. E.; Surdej, A.; Surdej, J. (September 1979). "Photoelectric observations of two unusual asteroids - 1978 CA and 1978 DA". Astronomy and Astrophysics Supplement Series. 37: 483–486. Bibcode:1979A&AS...37..483S.
  8. ^ Koehn, Bruce W.; Bowell, Edward G.; Skiff, Brian A.; Sanborn, Jason J.; McLelland, Kyle P.; Pravec, Petr; et al. (October 2014). "Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS) - 2009 January through 2009 June". The Minor Planet Bulletin. 41 (4): 286–300. Bibcode:2014MPBu...41..286K. ISSN 1052-8091.
  9. ^ Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael (January 2014). "Physical characterization of Warm Spitzer-observed near-Earth objects". Icarus. 228: 217–246. arXiv:1310.2000. Bibcode:2014Icar..228..217T. doi:10.1016/j.icarus.2013.10.004.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 13 January 2018.
  11. ^ "Horizons Batch for 2022-Sep-01 06:54 UT". JPL Horizons. Archived from the original on 17 January 2022. Retrieved 17 January 2022.

External links

2022 in space
Minor planets navigator
Small Solar System bodies
Authority control databases
Categories