228 Agathe

228 Agathe is a stony main belt asteroid, about 9 kilometers in diameter. It was discovered by Johann Palisa on 19 August 1882 at Vienna Observatory, Austria. Photometric observations during 2003 showed a rotation period of 6.48 ± 0.01 hours with a brightness variation of 0.27 ± 0.03 in magnitude. An earlier study yielded results that are consistent with these estimates.^[3] Agathe is the lowest numbered asteroid to have an Earth-MOID as low as 0.657 AU (98.3 million km).^[1] On 23 August 2029 the asteroid will be 0.659 AU (98.6 million km) from Earth.

DiscoveredbyJ. Palisa

DiscoverysiteVienna Observatory

Discoverydate19 August 1882

MPCdesignation

(228) Agathe

Quick facts Discovery, Discovered by ...

228 Agathe

Orbital diagram
Discovery[1]
Discovered by	J. Palisa
Discovery site	Vienna Observatory
Discovery date	19 August 1882
Designations
MPC designation	(228) Agathe
Named after	daughter of astronomer Theodor v. Oppolzer[2]
Alternative designations	A882 QA
Minor planet category	main-belt
Orbital characteristics[1]
Epoch 13 September 2023 (JD 2453300.5)
Uncertainty parameter 0
Observation arc	130.80 yr
Aphelion	2.73 AU (408 million km)
Perihelion	1.67 AU (250 million km)
Semi-major axis	2.20 AU (329 million km)
Eccentricity	0.24227
Orbital period (sidereal)	3.27 yr (1193.1 d)
Mean anomaly	63.67°
Mean motion	0° 18m 6.408s / day
Inclination	2.5359°
Longitude of ascending node	313.25°
Argument of perihelion	19.177°
Earth MOID	0.657 AU (98.3 million km)
Mars MOID	0.29 AU (43 million km)
Jupiter MOID	2.63 AU (393 million km)
TJupiter	3.624
Physical characteristics
Dimensions	9.30±0.8 km
Synodic rotation period	6.484 h (0.2702 d)
Geometric albedo	0.2082±0.043
Spectral type	B–V = 0.918 U–B = 0.596 S (Tholen), S (SMASS)
Absolute magnitude (H)	12.32

Close

Agathe was named after the youngest daughter of Austrian astronomer Theodor von Oppolzer (1841–1886), professor of astronomy in Vienna.^[2]