Astronomy:239 Adrastea

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Short description: Main-belt asteroid
239 Adrastea
000239-asteroid shape model (239) Adrastea.png
3D model based on lightcurve data
Discovery
Discovered byJohann Palisa
Discovery date18 August 1884
Designations
(239) Adrastea
Pronunciation/ædrəˈstə/
Named afterAdrasteia
A884 QA, 1915 TD
1955 MK1, 1956 UJ
Minor planet categoryMain belt
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc131.66 yr (48,087 d)
|{{{apsis}}}|helion}}3.66279 astronomical unit|AU (547.946 Gm)
|{{{apsis}}}|helion}}2.2695 AU (339.51 Gm)
2.96616 AU (443.731 Gm)
Eccentricity0.23486
Orbital period5.11 yr (1,865.9 d)
Average Orbital speed17.25 km/s
Mean anomaly233.617°
Mean motion0° 11m 34.584s / day
Inclination6.1746°
Longitude of ascending node180.634°
210.15°
Physical characteristics
Dimensions41.52±1.4 km[1]
Rotation period18.4707 h (0.76961 d)[1]
Geometric albedo0.0777±0.006[1]
Physicsunknown
unknown
Absolute magnitude (H)10.4[1]


Orbit of Adrastea (blue ring)

Adrastea (minor planet designation: 239 Adrastea) is a main belt asteroid. It was discovered by Johann Palisa on 18 August 1884 in Vienna, and was named after the Greek nymph Adrasteia. This asteroid is orbiting the Sun at a distance of 2.97 astronomical unit|AU with a period of 5.11 years and an eccentricity (ovalness) of 0.23. The orbital plane is tilted at an angle of 6.17° to the plane of the ecliptic.[1]

Photometric data collected during 2009 were used for light curve analysis of this asteroid, yielding a rotation period of 18.48±0.03 h with a brightness variation of 0.45±0.05 in magnitude. The result is close to the 18.347±0.003 h period from a study performed in 2003.[2] The asteroid is roughly 42 km in diameter.[1]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 "JPL Small-Body Database Browser: 239 Adrastea". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=239. 
  2. Carbo, Landry et al. (October 2009), "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2008 October thru 2009 March", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 36 (4): 152–157, Bibcode2009MPBu...36..152C. 

External links