5 Astraea

5 Astraea
Lightcurve-based 3D-model of Astraea
Discovery[1]
Discovered byK. L. Hencke
Discovery siteDriesen Obs.
Discovery date8 December 1845
Designations
(5) Astraea
Pronunciation/æˈstrə/[2]
Named after
Astraea (Greek goddess)[3]
1969 SE
main-belt[1][4] · (middle)
Astraea[5]
AdjectivesAstraean
SymbolThe historic planetary symbol for 5 Astraea (historical astronomical), The modern astrological symbol for 5 Astraea (modern astrological)
Orbital characteristics[4]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc171.93 yr (62,799 d)
Aphelion3.0659 AU
Perihelion2.0810 AU
2.5735 AU
Eccentricity0.1914
4.13 yr (1,508 d) 4.13 yr (1,508 d)
186.83°
0° 14m 19.32s / day
Inclination5.3677°
141.58°
358.75°
Proper orbital elements[6]
2.5761849 AU
0.1980486
4.5118628°
87.046396 deg / yr
4.13573 yr
(1510.574 d)
Precession of perihelion
52.210903 arcsec / yr
Precession of the ascending node
−57.357951 arcsec / yr
Physical characteristics
Dimensions169 km × 125 km × 83 km[7]
125 km[7]
48 900 km2[a]
Volume920 000 km3[a]
Mass(2.716 ± 0.326/0.45)×1018 kg[8]
Mean density
3.501 ± 0.420/0.581 g/cm3[8][b]
0.700 04 d (16.801 h)[7]
Equatorial rotation velocity
6.49 m/s[a]
North pole right ascension
115°/310° ± 5°
North pole declination
55° ± 5°
0.227[9]
S
8.74 to 12.89
6.85
0.15" to 0.041"

5 Astraea (/æˈstrə/) is an asteroid in the asteroid belt. This object is orbiting the Sun at a distance of 385 million kilometres (2.5735 AU) with a period of 4.13 yr and an orbital eccentricity of 0.19. The orbital plane is inclined at an angle of 5.37° to the plane of the ecliptic. It is spinning with a period of 16.8 h. The surface of Astraea is highly reflective and its composition is probably a mixture of nickeliron with silicates of magnesium and iron. It is an S-type asteroid in the Tholen classification system.[4]

  1. ^ a b Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  2. ^ "Astraea". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
  3. ^ Cite error: The named reference springer was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference AstDys-object was invoked but never defined (see the help page).
  6. ^ "AstDyS-2 Astraea Synthetic Proper Orbital Elements". Department of Mathematics, University of Pisa, Italy. Retrieved 1 October 2011.
  7. ^ a b c M. J. López-Gonzáles; E. Rodríguez (2005). "Lightcurves and poles of seven asteroids". Planetary and Space Science. 53: 1147. doi:10.1016/j.pss.2005.04.010.
  8. ^ a b Cite error: The named reference FiengaEtAl2020 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMPS was invoked but never defined (see the help page).


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