118 Peitho

118 Peitho
	3D convex shape model of 118 Peitho
Discovery
Discovered by	Karl Theodor Robert Luther
Discovery date	15 March 1872
Designations
MPC designation	(118) Peitho
Pronunciation	/ˈpaɪθoʊ/
Named after	Πειθώ Peithō
Alternative designations	A872 EA
Minor planet category	Main belt
Adjectives	Peithoian /paɪˈθoʊ.iən/
Orbital characteristics
	Epoch 31 July 2016 (JD 2457600.5)
	Uncertainty parameter 0
Observation arc	144.05 yr (52615 d)
Aphelion	2.8353 AU (424.15 Gm)
Perihelion	2.03988 AU (305.162 Gm)
Semi-major axis	2.43757 AU (364.655 Gm)
Eccentricity	0.16315
Orbital period (sidereal)	3.81 yr (1390.1 d)
Average orbital speed	18.95 km/s
Mean anomaly	51.1620°
Mean motion	0° 15m 32.328s / day
Inclination	7.7427°
Longitude of ascending node	47.701°
Argument of perihelion	33.403°
Earth MOID	1.05849 AU (158.348 Gm)
Jupiter MOID	2.4367 AU (364.53 Gm)
TJupiter	3.473
Physical characteristics
Dimensions	41.73±1.5 km
Mass	7.6×1016 kg
Equatorial surface gravity	0.0117 m/s2
Equatorial escape velocity	0.0220 km/s
Synodic rotation period	7.8055 h (0.32523 d); 7.823 h
Geometric albedo	0.2240±0.017
Temperature	~178 K
Spectral type	S
Absolute magnitude (H)	9.14

118 Peitho is a main-belt asteroid. It is probably an S-type asteroid, suggesting a siliceous mineralogy. It was discovered by R. Luther on March 15, 1872, and named after one of the two Peithos in Greek mythology. There have been two observed Peithoan occultations of a dim star: one was in 2000 and the other in 2003.^[4]^[5]

This body is orbiting the Sun with a period of 3.81 years and an eccentricity (ovalness) of 0.16. The orbital plane is inclined by 7.7° to the plane of the ecliptic. The cross-section diameter is ~42 km. In 2009, Photometric observations of this asteroid were made at the Palmer Divide Observatory in Colorado Springs, Colorado. The resulting asymmetrical light curve shows a synodic rotation period of 7.823 ± 0.002 hours with a brightness variation of 0.15 ± 0.02 in magnitude. This was reasonably consistent with independent studies performed in 1980 (7.78 hours) and 2009 (7.8033 hours).^[3] The lightcurve inversion process has been used to construct a model of this object,^[6] suggesting a blocky shape with flattened poles.

^ 'Pitho' in Noah Webster (1884) A Practical Dictionary of the English Language
^ ^a ^b Cite error: The named reference JPL was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference Warner2009 was invoked but never defined (see the help page).
^ von Boinik, I. F. B. "Planet (118) Peitho". Astronomische Nachrichten. 145: 31. Bibcode:1897AN....145...31V. doi:10.1002/asna.18981450107.
^ "NASA Planetary Data System". Archived from the original on 1 August 2009. Retrieved 21 December 2009.
^ Cite error: The named reference Franco2020 was invoked but never defined (see the help page).

[1] 'Pitho' in Noah Webster (1884) A Practical Dictionary of the English Language

[JPL-2] Cite error: The named reference JPL was invoked but never defined (see the help page).

[Warner2009-3] Cite error: The named reference Warner2009 was invoked but never defined (see the help page).

[4] von Boinik, I. F. B. "Planet (118) Peitho". Astronomische Nachrichten. 145: 31. Bibcode:1897AN....145...31V. doi:10.1002/asna.18981450107.

[5] "NASA Planetary Data System". Archived from the original on 1 August 2009. Retrieved 21 December 2009.

[Franco2020-6] Cite error: The named reference Franco2020 was invoked but never defined (see the help page).

[1]

[2]

[3]

[4]

[5]

[6]