29 Amphitrite

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29 Amphitrite
Discovered by A. Marth
Discovery time March 1, 1854
Other names A899 NG
Group Main belt
Reference date June 14, 2006 (JD 2453900.5)
Longest distance from the Sun 409.809 Gm (2.739 AU)
Shortest distance from the Sun 354.398 Gm (2.369 AU)
Longest distance from the center of its orbital path
("semi-major axis")
382.103 Gm (2.554 AU)
How egg-shaped its orbit is
How long it takes to complete an orbit 1491.013 d (4.08 a)
Average speed 18.61 km/s
Mean anomaly 229.662°
Angle above the reference plane
Longitude of where it comes up through the reference plane 356.501°
Angle between its shortest distance from what it orbits around and where it comes up through the reference plane
("argument of periapsis")
Size and Other Qualities
Measures 212.2 km
Mass 1.0×1019 kg
Average density 2.0 g/cm³
Gravity at its surface 0.0593 m/s²
Slowest speed able to escape into space
("escape velocity")
0.1122 km/s
How long it takes to turn around one time 0.2246 d (5.390 h) [1]
How much light it reflects 0.1793 (geometric[2]
Avg. surface temp. ~170 K
Light-band group
("spectral type")
Seeming brightness
("apparent magnitude")
8.58 to 11.38
True brightness
("absolute magnitude")
Seeming size
("angular diameter")
0.21" to 0.078"

29 Amphitrite is one of the biggest S-type asteroids, probably third in diameter after Eunomia and Juno, although Iris and Herculina are similar in size.

It is probably not a fully solid body, since its density is too low for a solid silicate object and much lower than Eunomia or Juno. Its orbit is less eccentric and inclined than those of its bigger cousins - being indeed the most circular of any asteroid found up to that point - and as a consequence it never becomes as bright as Iris or Hebe, especially as it is much farther from the Sun than those asteroids. It can reach magnitudes of around +8.6 at a favorable opposition, but more usually is around the binocular limit of +9.5.

Amphitrite was found by Albert Marth on March 1, 1854. It was the only asteroid he found. It is named after Amphitrite, a sea goddess in Greek mythology.

A moon is suspected based on the lightcurve data.[3] [4]

References[change | edit source]

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