Astronomy:99 Dike

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Short description: Main-belt asteroid
99 Dike
99Dike (Lightcurve Inversion).png
Three-dimensional model of 99 Dike created based on light-curve.
Discovery[1]
Discovered byAlphonse Borrelly
Discovery date28 May 1868
Designations
(99) Dike
Pronunciation/ˈdk/[2]
Named afterDike
A915 BA; 1935 UC; 1935 YL; 1939 UT; 1948 UE; 1948 WC; 1961 XJ; 1974 VB
Minor planet categoryMain belt
AdjectivesDikean /dˈkən/
Orbital characteristics[3][4]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc101.25 yr (36980 d)
|{{{apsis}}}|helion}}3.18448 astronomical unit|AU (476.391 Gm)
|{{{apsis}}}|helion}}2.14561 AU (320.979 Gm)
2.66504 AU (398.684 Gm)
Eccentricity0.19491
Orbital period4.35 yr (1589.1 d)
Average Orbital speed18.07 km/s
Mean anomaly18.1950°
Mean motion0° 13m 35.551s / day
Inclination13.8487°
Longitude of ascending node41.5307°
195.413°
Earth MOID1.13747 AU (170.163 Gm)
Jupiter MOID1.82393 AU (272.856 Gm)
TJupiter3.316
Physical characteristics
Dimensions69.04±2.7 km
Mass~3.9×1017 kg
Mean density2.0? g/cm3
Equatorial surface gravity
~0.0201 m/s2
Equatorial escape velocity
~0.0380 km/s
Rotation period18.127 h (0.7553 d)[4][5]
Geometric albedo0.0627±0.005[4]
0.058 [6]
Physics~172 K
C (Tholen)
Xk (Bus)[7]
Absolute magnitude (H)9.43


Dike /ˈdk/ (minor planet designation: 99 Dike) is a quite large and dark main-belt asteroid. Dike was discovered by Alphonse Borrelly on May 28, 1868. It was his first asteroid discovery. This object is named after Dike, the Greek goddess of moral justice. Among the first hundred numbered minor planets, 99 Dike was considered anomalously faint for over a century. However, this was later found to be untrue.[8]

This asteroid is orbiting the Sun with a period of 4.35 years and an eccentricity of 0.19. Its orbital plane is inclined by 13.8° to the plane of the ecliptic. The body spans a diameter of 69 km and it is classified as a C-type asteroid, which indicates it has a dark, carbonaceous surface. Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 18.127 ± 0.002 hours and varies in brightness by 0.22 ± 0.02 in magnitude.[5] However, according to Shrindan E. (2009) the rotation period is rather of 10.360 ± 0.001 h.[9]

The asteroid is located near the Juno clump of asteroids, but is most likely unrelated.[citation needed]

References

  1. "Discovery Circumstances: Numbered Minor Planets". http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html. 
  2. 'Dice, Dike' in Benjamin Smith (1903) The Century Dictionary and Cyclopedia
  3. "The Asteroid Orbital Elements Database". Lowell Observatory. http://ftp.lowell.edu/pub/elgb/astorb.html. 
  4. 4.0 4.1 4.2 "99 Dike". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=99;cad=1. 
  5. 5.0 5.1 Pilcher, Frederick (October 2011), "Rotation Period Determinations for 11 Parthenope, 38 Leda, 111 Ate 194 Prokne, 217 Eudora, and 224 Oceana", The Minor Planet Bulletin 38 (4): 183–185, Bibcode2011MPBu...38..183P. 
  6. Asteroid Data Sets
  7. DeMeo, Francesca E. et al. (2011), "An extension of the Bus asteroid taxonomy into the near-infrared", Icarus 202 (1): 160–180, doi:10.1016/j.icarus.2009.02.005, Bibcode2009Icar..202..160D, http://www.tara.tcd.ie/bitstream/2262/43276/1/PEER_stage2_10.1016%252Fj.icarus.2009.02.005.pdf, retrieved 22 March 2013.  See appendix A.
  8. Pilcher, Frederick (September 1979), "General Report of Position Observations by the A. L. P. O. Minor Planets Section", The Minor Planet Bulletin 7: 1–7, Bibcode1979MPBu....7....1P 
  9. Sheridan, Edwin (2009), "Lightcurve Results for 99 Dike, 313 Chaldaea, 872 Holda 1274 Delportia, and 7304 Namiki", Minor Planet Bulletin 36 (2): 55–56, Bibcode2009MPBu...36...55S. 

External links