204 Kallisto

204 Kallisto is a fairly typical, although sizeable Main belt asteroid. It is classified as an S-type asteroid. Like other asteroids of its type, it is light in colour. It was discovered by Johann Palisa on 8 October 1879, in Pola, and was named after the same nymph Callisto in Greek mythology as Jupiter's moon Callisto.

DiscoveredbyJohann Palisa

Discoverydate8 October 1879

MPCdesignation

(204) Kallisto

Pronunciation/kəˈlɪstoʊ/^[1]

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204 Kallisto

Lightcurve-base 3D-model of 204 Kallisto.
Discovery
Discovered by	Johann Palisa
Discovery date	8 October 1879
Designations
MPC designation	(204) Kallisto
Pronunciation	/kəˈlɪstoʊ/[1]
Named after	Callisto
Alternative designations	A879 TA
Minor planet category	Main belt
Adjectives	Kallistoan /kælɪˈstoʊən/
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	136.52 yr (49863 d)
Aphelion	3.13704 AU (469.295 Gm)
Perihelion	2.20244 AU (329.480 Gm)
Semi-major axis	2.66974 AU (399.387 Gm)
Eccentricity	0.17504
Orbital period (sidereal)	4.36 yr (1593.3 d)
Average orbital speed	18.22 km/s
Mean anomaly	230.567°
Mean motion	0° 13m 33.398s / day
Inclination	8.28673°
Longitude of ascending node	205.123°
Argument of perihelion	55.4125°
Physical characteristics
Dimensions	48.57±1.2 km[2] 50.36 ± 1.69 km[3]
Mass	(0.60 ± 1.81) × 1018 kg[3]
Synodic rotation period	19.489 h (0.8120 d)[4]
Geometric albedo	0.2082±0.010
Spectral type	S
Absolute magnitude (H)	8.89

Close

Photometric measurements during 2009 produced a lightcurve that indicated a sidereal rotation period of 19.489±0.002 h with a variation amplitude of 0.18±0.02 magnitudes. This result conflicted with previous determinations of the period, so the latter were ruled out.^[4]