130 Elektra

130 Elektra is a very large outer main belt asteroid. It was discovered 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, hence it probably has a Ceres-like composition. Spectral signatures of organic compounds have been seen on Elektra's surface cite journal|title="Organic Matter on Asteroid 130 Elektra"|journal=Science|pages=183|volume=238|year=1987|url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1987Sci...238..183C&db_key=AST&data_type=HTML&format=&high=444b66a47d14088|author=D.P. Cruikshank and R.H. Brown|doi=10.1126/science.238.4824.183|pmid=17800458] .

In the late 1990s, a network of astronomers worldwide gathered lightcurve data that was ultimately used to derive the spin states and shape models of 10 new asteroids, including (130) Elektra. [Durech., J.; Kaasalainen, M., Marciniak, A.; et al., “Physical models of ten asteroids from an observers' collaboration network,” Astronomy and Astrophysics , Volume 465, Issue 1, April I 2007, pp. 331-337 ] [ Durech, J.; Kaasalainen, M.; Marciniak, A.; Allen, W. H. et al. “Asteroid brightness and geometry,” Astronomy and Astrophysics, Volume 465, Issue 1, April I 2007, pp. 331-337.]

Optical observations have found a satellite of this asteroid. Using its orbit, Elektra's mass can be reliably found. The value of 1.3e|19 kg indicates an unusually high density (for asteroids) of 3.8 ± 0.3 g/cm³. Optical observations have also determined that Elektra's shape is quite irregular, as well as giving indications of albedo differences of 5-15% on its surface. This is uncommon, and corroborates with Elektra's high density to indicate that it is probably a solid, rather than fractured or rubble pile, body.

atellite (S/2003 (130) 1)

In 2003, a small moon of Elektra was detected using the Keck II telescope. The diameter of the satellite is 4 km and it orbits at a distance of about 1170 km. The satellite has been given the provisional designation S/2003 (130) 1. Due to only a few observations to date, its orbit is still relatively loosely constrained [http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Elektra.html 130 Elektra and S/2003 (130) 1] ", orbit data website maintained by F. Marchis.] . Infobox Planet
name=S/2003 (130) 1
width=28em
discovery=yes
physical_characteristics = yes
bgcolour=#A0FFA0
minorplanet=yes
discovery_ref = [http://cfa-www.harvard.edu/iauc/08100/08183.html#Item1 IAUC 8183] ]
discoverer=W. J. Merline, P. M. Tamblyn,
C. Dumas, L. M. Close,
C. R. Chapman, and F. Menard
discovered=15 August , 2003
mp_category=Main belt
orbit_ref=
semimajor= 1252 ± 30 km
eccentricity= unknown, likely small
inclination= uncertain
period=3.92 ± 0.03 d
avg_speed=23 m/s
satellite_of = 130 Elektra
dimensions= 6 ± 2 km
mass = ~4e|14 kg Assuming a similar density to the primary.]
escape_velocity= ~ 4 m/s
abs_magnitude=14.5 Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0 | minorplanet = yes | width = 25em
name=130 Elektra
discovery_ref = [ [http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html Discovery Circumstances: Numbered Minor Planets] , Minor Planet Centre]
discoverer=Christian Heinrich Friedrich Peters
discovered=February 17, 1873
alt_names=
mp_category=Main belt
orbit_ref = [ [ftp://ftp.lowell.edu/pub/elgb/astorb.html ASTORB] orbital elements database, Lowell Observatory]
epoch=December 31, 2006 (JD 2454100.5)
semimajor=467.521 Gm (3.125 AU)
perihelion=369.263 Gm (2.468 AU)
aphelion=565.778 Gm (3.782 AU)
eccentricity=0.210
period=2017.954 d (5.52 a)
inclination=22.838°
asc_node=145.635°
arg_peri=234.753°
mean_anomaly=225.604°
avg_speed=16.66 km/s
satellites = S/2003 (130) 1
dimensions=215×155 ± 12 kmBased in IRAS mean diameter of 182±12 km, a/b ratio of 1.4 as per the following references] [http://www.psi.edu/pds/resource/imps.html Supplemental IRAS Minor Planet Survey] ] [http://www.psi.edu/pds/resource/spin.html PDS node spin vector database] (in particular, the synthetic compiled value of a/b=1.4).] " [http://www.johnstonsarchive.net/astro/astmoons/am-00130.html (130) Elektra and S/2003 (130) 1] ", at Johnston's archive (maintained by W. R. Johnston).]
mass=1.28±0.10e|19 kg " [http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Elektra.html 130 Elektra and S/2003 (130) 1] ", F. Marchis] Error estimate derived from consideration of $M\; propto\; a^3/P^2$ and given errors in "a" and "P". See propagation of uncertainty.]
density=3.8 ± 0.3 g/cm³
surface_grav=0.07 m/s²On the extremities of the long axis.]
escape_velocity=0.13 km/s
sidereal_day =0.230103 d (5.52247 h)cite journal|author=F. Marchis "et al"|title="Shape, size and multiplicity of main-belt asteroids I. Keck Adaptive Optics survey"|journal=Icarus|volume=185|pages=39|year=2006|url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006Icar..185...39M&db_key=AST&data_type=HTML&format=&high=444b66a47d32271|doi=10.1016/j.icarus.2006.06.001]
axial_tilt = 157°
pole_ecliptic_lat = -88°
pole_ecliptic_lon = 68°
temperatures=yes
temp_name1 = Kelvin
mean_temp_1 = ~157
max_temp_1 = 251
temp_name2 = Celsius
max_temp_2 = -23°
albedo= 0.076 ± 0.011 " [http://www.psi.edu/pds/resource/imps.html Supplemental IRAS minor planet survey] "]
spectral_type = G " [http://www.psi.edu/pds/resource/taxonomy.html PDS node taxonomy database] "]
abs_magnitude=7.12

References

External links

*" [http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Elektra.html 130 Elektra and S/2003 (130) 1] ", orbit data website maintained by F. Marchis. Includes adaptive optics image of primary, and satellite orbit diagram.
* [http://www.johnstonsarchive.net/astro/astmoons/am-00130.html Data on (130) Elektra from Johnston's archive] (maintained by W. R. Johnston)