Astronomy:82 Alkmene

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Short description: Main-belt asteroid
82 Alkmene
A three-dimensional model of 82 Alkmene based on its light curve.
Discovery
Discovered byKarl Theodor Robert Luther
Discovery date27 November 1864
Designations
(82) Alkmene
Pronunciation/ælkˈmiːniː/[1]
Named afterAlcmene
Minor planet categoryMain belt
AdjectivesAlkmenean /ælkˈmiːniən/[2]
Orbital characteristics
Epoch 9 December 2014 (JD 2457000.5)
|{{{apsis}}}|helion}}3.3701 AU
|{{{apsis}}}|helion}}2.1609 AU
2.7655 AU
Eccentricity0.2186
Orbital period4.60 yr
Average Orbital speed17.70 km/s
Mean anomaly192.56°
Inclination2.8286°
Longitude of ascending node25.507°
111.27°
Physical characteristics
Dimensions61±1.5 km (IRAS)[3]
Mass2.4×1017 kg (assumed)
Rotation period12.999 h[3]
Geometric albedo0.208[3]
S[3]
Absolute magnitude (H)8.40[3]


Alkmene (minor planet designation: 82 Alkmene) is a main-belt asteroid. Alkmene was discovered by R. Luther on 7 November 1864 and named after Alcmene, the mother of Herakles in Greek mythology. Based on IRAS data, Alkmene is estimated to be about 61 kilometres (38 mi) in diameter.[3] A satellite has been suggested based on 1985 lightcurve data.[4]

Asteroid Alkmene occulted the apparent magnitude 7.5 star HIP 99229 in the constellation of Capricornus on 18 September 2014 around 06:41 UT (17 September 23:41 PDT) and was centered on Sacramento, CA.[5][6] Alkmene projected an eclipse shadow that moves at about 3.2 km/s (2 mi/s). Asteroid occultations allow for accurate 2-dimensional mapping of an asteroids silhouette when observed by multiple telescopes separated by about 10 km (6.2 mi).

References

  1. ↑ 'Alcmene, Alkmene' in The Century Dictionary and Cyclopedia (1895)
  2. ↑ Mairéad McAuley (2015), Reproducing Rome, p. 126; stress determined by verse in George Chapman, Gentleman Usher, Thomas Parrott 1907 ed., p. 220.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 "JPL Small-Body Database Browser: 82 Alkmene". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=82. 
  4. ↑ "Other reports of asteroid/TNO companions". http://www.johnstonsarchive.net/astro/asteroidmoonsq.html. 
  5. ↑ Interactive GoogleMap of Shadow Path
  6. ↑ "(82) Alkmene / HIP 99229 event on 2014 Sep 18, 06:41 UT". http://www.asteroidoccultation.com/2014_09/0918_82_32999.htm.