203 Pompeja

203 Pompeja is a fairly large main-belt asteroid. It was discovered by C. H. F. Peters on September 25, 1879, in Clinton, New York, and named after Pompeii, the Roman town destroyed in a volcanic eruption in AD 79. This asteroid is orbiting the Sun at a distance of 2.74 AU with an eccentricity (ovalness) of 0.06 and a period of 4.53 yr. The orbital plane is tilted at an angle of 3.2° to the plane of the ecliptic.^[2]

DiscoveredbyC. H. F. Peters

Discoverydate25 September 1879

MPCdesignation

(203) Pompeja

Pronunciation/pɒmˈpiːə/^[1]

Quick facts Discovery, Discovered by ...

203 Pompeja

Orbital diagram
Discovery
Discovered by	C. H. F. Peters
Discovery date	25 September 1879
Designations
MPC designation	(203) Pompeja
Pronunciation	/pɒmˈpiːə/[1]
Named after	Pompeii
Alternative designations	A879 SA, 1895 EA
Minor planet category	Main belt
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	136.43 yr (49,832 d)
Aphelion	2.897 AU (433.4 Gm)
Perihelion	2.577 AU (385.5 Gm)
Semi-major axis	2.737 AU (409.4 Gm)
Eccentricity	0.058490
Orbital period (sidereal)	4.53 yr (1,653.6 d)
Average orbital speed	18.01 km/s
Mean anomaly	47.6383°
Mean motion	0° 13m 3.72s / day
Inclination	3.1780°
Longitude of ascending node	347.916°
Argument of perihelion	57.060°
Physical characteristics
Mean diameter	124.592±1.079 km[2]
Mass	(1.251 ± 0.640/0.401)×1018 kg[3]
Mean density	1.626 ± 0.831/0.521 g/cm3[3][a]
Synodic rotation period	24.052 h (1.0022 d)[4][2]
Geometric albedo	0.036±0.006[2]
Spectral type	DCX:
Absolute magnitude (H)	8.97[2]

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Based upon photometric observations taken during 2011, it has a synodic rotation period of 24.052 ± 0.001 h, with a peak-to-peak amplitude of 0.10 ± 0.01 in magnitude. Because the rotation period nearly matches that of the Earth, it required coordinated observations from multiple observatories at widely spaced latitudes to produce a complete light curve.^[4] As discovered in 2021, Pompeja alongside the main-belt asteroid 269 Justitia have very red colors due to tholins on its surface, similar to trans-Neptunian objects. These asteroids are therefore thought to have formed in the outer Solar System despite their current orbits within the asteroid belt.^[5]