29 Amphitrite

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0
name=29 Amphitrite
discoverer=A. Marth
discovered=March 1, 1854
alt_names=A899 NG
mp_category=Main belt
epoch=June 14, 2006 (JD 2453900.5)
semimajor=382.103 Gm (2.554 AU)
perihelion=354.398 Gm (2.369 AU)
aphelion=409.809 Gm (2.739 AU)
eccentricity=0.073
period=1491.013 d (4.08 a)
inclination=6.096°
asc_node=356.501°
arg_peri=63.433°
mean_anomaly=229.662°
avg_speed=18.61 km/s
dimensions=212.2 km ^MPCit_JPL|29
mass=1.0e|19 kg
density=2.0 g/cm³
surface_grav=0.0593 m/s²
escape_velocity=0.1122 km/s
rotation=0.2246 d (5.390 h) ^{[http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_DERIVED_LIGHTCURVE_V8_0/data/lc.tab]}
spectral_type=S
magnitude = 8.58 to 11.38
abs_magnitude=5.85
albedo=0.1793 (geometric) ^{[http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_ALBEDOS_V1_1/data/albedos.tab]}
angular_size = 0.21" to 0.078"
single_temperature=~170 K

29 Amphitrite (pronEng|ˌæmfɪˈtraɪti, _gr. "Αμφιτρίτη)" is one of the largest 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 larger cousins - being indeed the most circular of any asteroid discovered up to that point - and as a consequence it never becomes as bright as Iris or Hebe, especially as it is much further 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 discovered by Albert Marth on March 1, 1854. It was his only asteroid discovery. It is named after Amphitrite, a sea goddess in Greek mythology.

A satellite is suspected based on the lightcurve data. [ cite journal
last = Tedesco
first = E. F.
authorlink = Edward F. Tedesco
year = 1979
month = March
title = "Binary Asteroids: Evidence for Their Existence from Lightcurves"
journal = Science, New Series
volume = 203
issue = 4383
pages = 905–907
url = http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1979Sci...203..905T&db_key=AST&data_type=HTML&format=&high=42c888df4628097 ] [cite conference
first = T. C.
last = van Flandern
authorlink = Thomas C. van Flandern
coauthors = Tedesco, E. F.; Binzel, R. P.
year = 1979
title = "Satellites of asteroids"
booktitle = "Asteroids"
publisher = University of Arizona Press
location = Tucson, AZ
pages = 443-465
url = http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1979aste.book..443V&db_key=AST&data_type=HTML&format=&high=44de2b43ec21015 ]

References

External links

* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=29;orb=1 Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=29 Ephemeris]