84 Klio

84 Klio is a fairly large and very dark main-belt asteroid. It was discovered by R. Luther on August 25, 1865, and named after Clio, the Muse of history in Greek mythology. The name Clio had previously been suggested by the discoverer of 12 Victoria, and that is the name B. A. Gould, editor of the prestigious Astronomical Journal, adopted for that asteroid, because of the controversy over the name Victoria. An occultation by Klio over a dim star was observed on April 2, 1997.

84 Klio

Orbital diagram
Discovery
Discovered by	Karl Theodor Robert Luther
Discovery date	August 25, 1865
Designations
MPC designation	(84) Klio
Pronunciation	/ˈklaɪ.oʊ/[1]
Named after	Clio
Minor planet category	Main belt · Klio
Adjectives	Klionian /klaɪˈoʊniən/ Klioian /klaɪˈoʊ.iən/[2]
Orbital characteristics[3]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion	436.886 Gm (2.920 AU)
Perihelion	269.828 Gm (1.804 AU)
Semi-major axis	353.357 Gm (2.362 AU)
Eccentricity	0.236
Orbital period (sidereal)	1325.961 d (3.63 a)
Mean anomaly	326.072°
Inclination	9.334°
Longitude of ascending node	327.651°
Argument of perihelion	14.690°
Physical characteristics
Dimensions	79.16 ± 1.6 km[3]
Mass	(3.93 ± 1.48/1.28)×1017 kg[4]
Mean density	1.521 ± 0.572/0.497 g/cm3[4][a]
Synodic rotation period	23.562 ± 0.001 h[3][5]
Geometric albedo	0.053[3][6]
Spectral type	G[3]
Absolute magnitude (H)	9.36[3]

Photometric observations of this asteroid during 2007 at the Organ Mesa Observatory in Las Cruces, New Mexico were used to create a light curve plot. This showed a synodic rotation period of 23.562 ± 0.001 hours and a brightness variation of 0.21 ± 0.02 magnitude during each cycle.^[5]

Perturbation

Perturbations of asteroid 52 Europa by 84 Klio suggest that 52 Europa would have a mass as high as 1.68×10²⁰ kg.^[7][b] But this would require Europa to have an unrealistic density of 10.6 g/cm³.^[7] Further observations of Klio will be needed to properly refine the mass of both asteroid Europa and Klio.

Notes

1. Assuming a diameter of 79 ± 4.867 km.
2. High estimate for mass of asteroid Europa 0.851 / Mass of Ceres 4.75) * Mass of Ceres 9.43E+20 = 1.689E+20