161989 Cacus

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
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]
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  2. ^ a b c d Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Nugent-2016 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference WISE was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Degewij-1978b was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference lcdb was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Schuster-1979 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Koehn-2014 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Thomas-2014 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference MPC-Circulars-Archive was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Horizons2022 was invoked but never defined (see the help page).