130 Elektra

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130 Elektra is a very big farther main belt asteroid. It was found by C. H. F. Peters on February 17, 1873 and named after Electra, an avenger in Greek mythology.

Its spectrum is of the G type, so it is probably made up like Ceres. Spectral signatures of organic compounds have been seen on Elektra's surface [1]

Recent optical sightings have found a moon (see below). Using its orbit, Elektra's mass can be found more correctly. The value of 1.3×1019 kg indicates an unusually high density (for asteroids) of 3.8 ± 0.3 g/cm³. Optical sightings have also determined that Elektra's shape is quite non-spherical, as well as giving indications of albedo differences of 5-15% on its surface.[2]

Moon (S/2003 (130) 1)[change | change source]

In 2003, a small moon of Elektra was detected using the Keck II telescope. The diameter of the moon is 4 km and it orbits at a distance of about 1170 km. The moon has been given the provisional designation S/2003 (130) 1. Due to only a few sightings to date, its orbit is still not well known [3]

S/2003 (130) 1
Discovery and designation [4]
Discovered by W. J. Merline, P. M. Tamblyn,
C. Dumas, L. M. Close,
C. R. Chapman, and F. Menard
Discovery date 15 August, 2003
Names
Category Main belt
Orbit [3]
Longest distance from the center of its orbital path
("semi-major axis")
1252 ± 30 km
How long it takes to complete an orbit 3.92 ± 0.03 d
Average speed 23 m/s
Angle above the reference plane
("inclination")
uncertain
What it orbits 130 Elektra
Size and other qualities
Measurements 6 ± 2 km [2]
Mass ~4×1014 kg [5]
Escape velocity ~ 4 m/s
True brightness
("absolute magnitude")
14.5[2]
130 Elektra
Discovery and designation [6]
Discovered by Christian Heinrich Friedrich Peters
Discovery date February 17, 1873
Names
Other names  
Category Main belt
Orbit [7]
Reference date December 31, 2006 (JD 2454100.5)
Longest distance from the Sun 565.778 Gm (3.782 AU)
Shortest distance from the Sun 369.263 Gm (2.468 AU)
Longest distance from the center of its orbital path
("semi-major axis")
467.521 Gm (3.125 AU)
How long it takes to complete an orbit 2017.954 d (5.52 a)
Average speed 16.66 km/s
Mean anomaly 225.604°
Angle above the reference plane
("inclination")
22.838°
Natural things which orbit it S/2003 (130) 1
Size and other qualities
Measurements 215×155 ± 12 km[8][9][10][11]
Mass 1.28±0.10×1019 kg [12][13]
Average density 3.8 ± 0.3 g/cm³ [3]
Surface gravity 0.07 m/s²[14]
Escape velocity 0.13 km/s[14]
Angle at which it turns
(in relation to its orbit)
157°
How much light it reflects 0.076 ± 0.011 [15]
Surface temp. Min. Avg. Max.
Kelvin ~157 251
Celsius -23°
Spectral type G [16]
True brightness
("absolute magnitude")
7.12 [9]

References[change | change source]

  1. D.P. Cruikshank and R.H. Brown (1987). "Organic Matter on Asteroid 130 Elektra". Science 238: 183. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1987Sci...238..183C&db_key=AST&data_type=HTML&format=&high=444b66a47d14088.
  2. 2.0 2.1 2.2 F. Marchis (2006). "Shape, size and multiplicity of main-belt asteroids I. Keck Adaptive Optics survey". Icarus 185 (1): 39–63. doi:10.1016/j.icarus.2006.06.001. PMC 2600456. PMID 19081813.
  3. 3.0 3.1 3.2 130 Elektra and S/2003 (130) 1, orbit data website maintained by F. Marchis. Archived 16 January 2010 at WebCite
  4. IAUC 8183[dead link]
  5. Assuming a similar density to the primary.
  6. Discovery Circumstances: Numbered Minor Planets, Minor Planet Centre Archived 20 June 2007 at WebCite
  7. ASTORB orbital elements database, Lowell Observatory
  8. Based in IRAS mean diameter of 182±12 km, a/b ratio of 1.4 as per the following references
  9. 9.0 9.1 Supplemental IRAS Minor Planet Survey Archived 17 January 2010 at WebCite
  10. PDS node spin vector database (in particular, the synthetic compiled value of a/b=1.4). Archived 17 January 2010 at WebCite
  11. (130) Elektra and S/2003 (130) 1, at Johnston's archive (maintained by W. R. Johnston). Archived 26 May 2011 at WebCite
  12. 130 Elektra and S/2003 (130) 1, F. Marchis Archived 16 January 2010 at WebCite
  13. Error estimate derived from consideration of M \propto a^3/P^2 and given errors in a and P. See propagation of uncertainty.
  14. 14.0 14.1 On the extremities of the long axis.
  15. Supplemental IRAS minor planet survey Archived 17 January 2010 at WebCite
  16. PDS node taxonomy database Archived 16 January 2010 at WebCite

Other websites[change | change source]