49 Pales

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49 Pales
Discovery[1]
Discovered by Hermann Goldschmidt
Discovery site Paris Observatory
Discovery date 19 September 1857
Designations
MPC designation (49) Pales
Named after
Pales
Main belt [1]
Orbital characteristics[2]
Epoch 23 March 2018
Aphelion 3.7989 AU
Perihelion 2.4030 AU
3.10093 AU
Eccentricity 0.22507
1994.51 days (5.46 years)
169.53°
Inclination 3.17°
285.646°
111.146°
Physical characteristics
Dimensions 149.80 ± 3.8 km
Mean diameter[3]
Mass 2.69×1018 kg[4]
20.7057 ± 0.0002[5] hours
20.705 ± 0.002[6] hours
20.704 ± 0.001[7] hours
Albedo 0.0597 ± 0.003[3]
Spectral type
C[8]
7.8[9]

49 Pales /ˈplz/ is a large, dark main-belt asteroid. It was discovered by German-French astronomer Hermann Goldschmidt on 19 September 1857 from his balcony in Paris.[10] The asteroid is named after Pales, the goddess of shepherds in Roman mythology. Since it was discovered on the same night as 48 Doris, geologist Élie de Beaumont suggested naming the two "The Twins".[11]

Pales has been studied by radar.[12] It has a rotation period of 20.705 ± 0.002 hours and a lightcurve with an amplitude of 0.18 mag. The lightcurve shows 4 maxima and 4 minima per cycle, suggesting an irregular shape.[6] The previously accepted period of 10.42 hours with 2 maxima and minima per cycle[13] was proven to be wrong by Pilcher in 2016, showing that correct rotation periods still have not been found for all low-numbered asteroids.[7]

References[edit]

  1. ^ a b "49 Pales". JPL Small-Body Database. Jet Propulsion Laboratory. Retrieved 26 June 2018. 
  2. ^ "(49) Pales". AstDyS. Italy: University of Pisa. Retrieved December 29, 2008. 
  3. ^ a b Tedesco; et al. (2004). "Supplemental IRAS Minor Planet Survey (SIMPS)". IRAS-A-FPA-3-RDR-IMPS-V6.0. Planetary Data System. Archived from the original on 17 January 2010. Retrieved December 29, 2008. 
  4. ^ Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 29 January 2009. Retrieved 2008-12-29. 
  5. ^ Romeuf, David; Behrend, Raoul (7 January 2016). "Courbes de rotation d'astéroïdes et de comètes" (in French). Retrieved 26 June 2018. 
  6. ^ a b Pilcher, Frederick (2017). "Rotation Period Determinations for 49 Pales, 96 Aegle, 106 Dione 375 Ursula, and 576 Emanuela". Minor Planet Bulletin. Retrieved 26 June 2018. 
  7. ^ a b Pilcher, Frederick; Benishek, Vladimir; Klinglesmith, Daniel A. (2016). "Rotation Period, Color Indices, and H-G parameters for 49 Pales". Minor Planet Bulletin. Retrieved 26 June 2018. 
  8. ^ Neese (2005). "Asteroid Taxonomy". EAR-A-5-DDR-TAXONOMY-V5.0. Planetary Data System. Archived from the original on 17 January 2010. Retrieved 27 December 2008. 
  9. ^ Tholen (2007). "Asteroid Absolute Magnitudes". EAR-A-5-DDR-ASTERMAG-V11.0. Planetary Data System. Archived from the original on June 17, 2012. Retrieved December 29, 2008. 
  10. ^ "Discovery Circumstances: Numbered Minor Planets (1)-(5000)". IAU: Minor Planet Center. Archived from the original on 2 February 2009. Retrieved December 29, 2008. 
  11. ^ Schmadel, Lutz (2003), Dictionary of minor planet names (fifth ed.), Germany: Springer, p. 19, ISBN 3-540-00238-3. 
  12. ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 2011-10-30. 
  13. ^ Schober, H. J.; et al. (April 1979), "Photoelectric photometry and rotation periods of three large and dark asteroids - 49 Pales, 88 Thisbe and 92 Undina", Astronomy and Astrophysics Supplement Series, 36, pp. 1–8, Bibcode:1979A&AS...36....1S. 

External links[edit]