398 Admete, provisional designation 1894 BN, is a dark, carbonaceous asteroid from the outer region of the asteroid belt, about 47 kilometers in diameter. It was discovered on 28 December 1894, by French astronomer Auguste Charlois at Nice Observatory in southeastern France.[6]

398 Admete
Orbital diagram
Discovery [1]
Discovered byA. Charlois
Discovery siteNice Observatory
Discovery date28 December 1894
Designations
(398) Admete
Pronunciation/ædˈmt/[2]
Named after
Admete (Greek mythology)[3]
1894 BN · 1951 LP
1952 QC1 · A907 RE
main-belt · (outer)[4]
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc120.95 yr (44176 d)
Aphelion3.3515 AU (501.38 Gm)
Perihelion2.1269 AU (318.18 Gm)
2.7392 AU (409.78 Gm)
Eccentricity0.22354
4.53 yr (1655.9 d)
314.19°
0° 13m 2.64s / day
Inclination9.5259°
279.98°
159.02°
Earth MOID1.144 AU (171.1 Gm)
Jupiter MOID1.91915 AU (287.101 Gm)
TJupiter3.294
Physical characteristics
Dimensions46.98±2.3 km (IRAS:6)[1]
46.93 km (derived)[4]
11.208 h (0.4670 d)[1]
11.208±0.001 h[5]
0.0607±0.006 (IRAS:6)[1]
0.0555 (derived)[4]
SMASS = C[1]
C[4]
10.4[1]

The dark C-type asteroid orbits the Sun at a distance of 2.1–3.4 AU once every 4 years and 6 months (1,656 days). Its orbit shows an eccentricity of 0.22 and is tilted by 10 degrees to the plane of the ecliptic. The body's surface has a low albedo of 0.06, which is a typical value for carbonaceous asteroids.[1]

It had been titled the lowest numbered asteroid with no previously known period until its opposition in 2014, when a photometric light-curve analysis was performed at the Uruguayan Los Algarrobos Observatory (OLASU, I38). It rendered a rotation period of 11.208±0.001 hours with a brightness amplitude of 0.13±0.02 in magnitude.[5] Still in 2014, Eduardo Alvarez at OLASU went on to determine the period of the next lowest numbered asteroid with no previously known period, 457 Alleghenia. Since then all asteroids numbered up to 500 had their rotation period determined. As of 2014, there are still 22 asteroids with no known period up to number 1000.[5]

The minor planet was named from Greek mythology for Admete, daughter of king Eurystheus, who appointed the Twelve Labors of Heracles, after whom the minor planet 5143 Heracles is named. One of the labors was to obtaining the golden girdle of Hippolyta, because Admete coveted it.[3]

References

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  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 398 Admete (1894 BN)" (2015-12-11 last obs.). Jet Propulsion Laboratory. Retrieved 10 May 2016.
  2. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ a b Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (398) Admete. Springer Berlin Heidelberg. p. 48. doi:10.1007/978-3-540-29925-7_399. ISBN 978-3-540-29925-7.
  4. ^ a b c d "LCDB Data for (398) Admete". Asteroid Lightcurve Database (LCDB). Retrieved 9 January 2016.
  5. ^ a b c Alvarez, Eduardo Manuel (October 2014). "Period Determination for 398 Admete: the Lowest Numbered Asteroid with no Previously Known Period". The Minor Planet Bulletin. 41 (4): 254–255. Bibcode:2014MPBu...41..254A. ISSN 1052-8091.
  6. ^ "398 Admete (1894 BN)". Minor Planet Center. Retrieved 9 January 2016.
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