139 Juewa

139 Juewa
Discovery
Discovered byJames Craig Watson
Discovery date10 October 1874
Designations
(139) Juewa
Pronunciation/dʒuˈeɪwɑː/
Mandarin: [ɻuîxuǎ]
A874 TA
Main belt
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc121.07 yr (44222 d)
Aphelion3.26884 AU (489.012 Gm)
Perihelion2.29261 AU (342.970 Gm)
2.78073 AU (415.991 Gm)
Eccentricity0.17553
4.64 yr (1693.7 d)
60.2817°
0° 12m 45.187s / day
Inclination10.9127°
1.83417°
165.566°
Physical characteristics
Dimensions148.3±4.3 km × 142.3±15.6 km
151.116±1.596 km[1]
161.43±7.38 km[2]
Mass(5.54±2.20)×1018 kg[2]
(3.262 ± 0.778/0.933)×1018 kg[3]
Mean density
2.51±1.05 g/cm3[2]
1.805 ± 0.430/0.516 g/cm3[3]
Equatorial surface gravity
0.0438 m/s²
Equatorial escape velocity
0.0828 km/s
20.991 h (0.8746 d)
0.052±0.015[1]
0.0444±0.0164[4]
Temperature~167 K
CP (Tholen)[4]
8.06,[1] 7.924[4]

139 Juewa /dʒuˈeɪwɑː/ is a very large and dark main belt asteroid. It is probably composed of primitive carbonaceous material. It was the first asteroid discovered from China.

Juewa was discovered from Beijing by the visiting American astronomer James Craig Watson on 10 October 1874; Watson was in China to observe the transit of Venus. Watson asked Prince Gong to name the asteroid. Gong's choice was 瑞華星 (roughly, "Star of China’s Fortune"). Watson used the first two characters ('star' being redundant), transliterating them Juewa in Wade–Giles convention of the time. (In pinyin, 瑞華 is transliterated ruìhuá.)[5]

Multichord occultation by 139 Juewa, observed 31 August 2013 from N.S.W., Australia.
139 Juewa
Traditional Chinese瑞華星
Simplified Chinese瑞华星
Literal meaningAuspicious star of Huaxia [China]
Transcriptions
Standard Mandarin
Hanyu PinyinRuìhuáxīng
Wade–Gilesjui4 hua2 hsing1
IPA[ɻwêɪ.xwǎ.ɕíŋ]

Since 1988 there have been 8 reported stellar occultations by Juewa. From the occultation on 31 August 2013 the best fit ellipse measures 148.3±4.3 km × 142.3±15.6 km.[6]

13-cm radar observations of this asteroid from the Arecibo Observatory between 1980 and 1985 were used to produce a diameter estimate of 172 km.[7] Based upon radar data, the near surface solid density of the asteroid is 1.5±0.5 g/cm3.[8]

  1. ^ a b c d Cite error: The named reference JPL was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Carry2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference FiengaEtAl2020 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Pravec2012 was invoked but never defined (see the help page).
  5. ^ Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 28. ISBN 978-3-540-00238-3.
  6. ^ "Asteroid Occultations". sbn.psi.edu. Retrieved 22 June 2018.
  7. ^ Cite error: The named reference Ostro1985 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Magri2001 was invoked but never defined (see the help page).