130 Elektra

Asteroid with 3 moons Electra (star), a star in the constellation Taurus September 2018 yes 130 Elektra #D6D6D6 130 Elektra VLT (2021), deconvolved.pdf VLT-SPHERE adaptive optics image of Elektra taken on 5 August 2019 C. H. F. Peters Litchfield Obs. 17 February 1873 (130) Elektra A873 DA ᵻ ˈ l ɛ k t r əElectra Elektrian ᵻ ˈ l ɛ k t r i ə nGeorge William Cox (1878) History of Greece Electra main-belt(outer)background 1 July 2021 (JD 2459396.5) 0 127.53 yr (46,582 d) 3.7808 AU 2.4725 AU 3.1266 AU 0.20923 5.53 yr (2,019 d) 87.758° 0.178275 ms / day 22.782° 145.009° 237.588° 3 262 x 205 x 164 km ± 3% 0.43Flattening derived from the maximum aspect ratio (c/a): , where (c/a) = 0.57 0.04. 199 2 km 6.4 0.2 18 kg7.0 0.3 18 kg 1.55 0.07 g/cm3 5.224663 0.000001 h 156° –88° 71° 0.067 (calculated)0.086 0.015 (NEOWISE)0.0755 0.0110 (IRAS) G (Tholen)Ch (SMASS) 7.477.217.05 130 Elektra is a large outer main-belt asteroid and quadruple system with three minor-planet moons. It was discovered on 17 February 1873 by astronomer Christian Peters at Litchfield Observatory, New York, and named after Electra, an avenger in Greek mythology. Description thumb|left|Lightcurve-based 3D-model of (130) Elektra (130) Elektra has the spectrum of a G-type asteroid; hence it probably has a Ceres-like surface. Spectral signatures of organic compounds have been seen on Elektra's surfaceD.P. Cruikshank R.H. Brown amp 1987 Organic matter on asteroid 130 Elektra Science 238 4824 183–184 17800458 1987Sci...238..183C 10.1126/science.238.4824.183 46168765 and it displays evidence of aqueous alteration.Fornasier S. Lazzarin M. Barbieri C. Barucci M.A. February 1999 Spectroscopic comparison of aqueous altered asteroids with CM2 carbonaceous chondrite meteorites Astronomy and Astrophysics Supplement 135 65–73 10.1051/aas:1999161 free 1999A&AS..135...65F 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. The light curve of (130) Elektra forms a double sinusoid while the shape model is elongated and the derived rotation axis is perpendicular to the plane of the ecliptic. Durech J. Kaasalainen M. Marciniak A. Allen W. H. 2007 Asteroid brightness and geometry Astronomy and Astrophysics 465 1 331–337 10.1051/0004-6361:20066347 free 2007A&A...465..331D Optical observations have found three satellites of this asteroid. Once the orbits are known, Elektra's mass can be reliably found. The value of 6.6 × 18 kg indicates a density of 1.3 ± 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. Occultations thumb|left|Occultation profile of Elektra as observed from Europe on 21 April 2018 Elektra has been observed to pass in front of a dozen stars since 2007, most notably on 21 April 2018 when over 30 mostly citizen astronomers spread across five European countries recorded the sudden drop in light of an 11th magnitude star. The sky-plane plot of the chords reveals a peanut-shaped body, possibly the result of a two-body merger early in the history of the Solar System. left Satellites section new orbital parameters, particularly for the third satellite, per Fuksa et al. 2023 June 2024 Elektra has three orbiting natural satellites, all of which are unnamed and measure a few kilometres across. Together with the primary body Elektra, they comprise a quadruple system. Given their similar spectra, these satellites are thought to be fragments of Elektra that were created from a disruptive impact. 2021 11, Elektra has the most satellites of any main-belt asteroid, and is the only known quadruple asteroid system in the Solar System. All three satellites are faint and orbit closely to Elektra, which makes them difficult to observe due to Elektra's bright glare obscuring them. The largest telescopes with adaptive optics systems and advanced image processing techniques are required for detailed study of the satellites' properties. + Moons of Elektra ("Alpha") Name Discovered Announced Diameter (km) Semi-major axis (km) Orbital period (d) Eccentricity Inclination (°)With respect to the celestial equator Ascending node (°) Arg. of perihelion (°) Mean anomaly (°) undesignated ("Delta")Inner moon of Elektra unofficially called "Delta" or S/2014 (130) 2 by G. Valvano et al. (2023). 2014-12-09 2021-11-06 1.6 0.4 344 5 0.679 0.001 0.33 0.05 129 24 127 18 23 11 — S/2014 (130) 1 ("Gamma") 2014-12-06 2014-12-16 2.0 0.4 501 7 1.192 0.002 0.03 0.03 156 7 187 10 235 18 — S/2003 (130) 1 ("Beta") 2003-08-15 2003-08-17 6.0 0.6 1297.58 0.54 5.287 0.001 0.0835 0.0096 160.21 1.50 176.1 5.7 184.4 14.1 117.3 11.7 S/2003 (130) 1 ("Beta") S/2003 (130) 1 ("Beta") is the largest and outermost satellite of Elektra, around 6 km mi in diameter, assuming the same albedo as the primary. It was discovered on 15 August 2003, by a team of astronomers led by W. J. Merline using the Keck II telescope at the Mauna Kea Observatory in Hawaii. The discovery images showed that the satellite had an apparent magnitude difference of 8.5 in the near-infrared K-band. The team confirmed the existence of the satellite after reobserving it with the Keck II telescope on 17 August 2003. The discovery was announced on that same day and the satellite was given the provisional designation S/2003 (130) 1. S/2003 (130) 1 orbits 1300 km mi from Elektra with a period of 5.3 days. Its orbit has a moderate eccentricity of 0.08 and an inclination of 160° with respect to the celestial equator. Preliminary simulations of the Elektra system show that S/2003 (130) 1's semi-major axis oscillates less than 1.4 km mi over 20 years. Near-infrared observations from December 2014 show that S/2003 (130) 1 along with S/2014 (130) 1 display a similar spectrum to Elektra, supporting the hypothesis that they are fragments from a disruptive collision. S/2014 (130) 1 ("Gamma") thumb|Moving image of 130 Elektra's 3 moons. The orange orbit is of S/2003 (130) 1, while the green and blue orbits are of S/2014 (130) 1 and the inner moon respectively. S/2014 (130) 1 ("Gamma") is the second satellite of Elektra by distance and order of discovery. It was discovered on 6 December 2014, by a team of astronomers led by B. Yang using the SPHERE adaptive optics system on the Very Large Telescope's Melipal (UT3) telescope at Cerro Paranal, Chile. Discovery observations showed that the satellite had a near-infrared magnitude difference of 10, corresponding to a diameter of about 2 km mi if it has the same albedo as the primary. The discovery was announced on 16 December 2014, but the satellite was mistakenly designated S/2014 (130) 2 before being immediately corrected to S/2014 (130) 1. S/2014 (130) 1 orbits 500 km mi from Elektra with a period of 1.2 days—about two and a half times closer and four times quicker than the outer satellite S/2003 (130) 1. Its roughly-circular orbit is inclined 156° with respect to the celestial equator. Preliminary simulations of the Elektra system show that S/2014 (130) 1's semi-major axis oscillates less than 100 m ft over 20 years. Near-infrared observations from December 2014 show that S/2014 (130) 1 along with S/2003 (130) 1 display a similar spectrum to Elektra. Inner satellite ("Delta") On 6 November 2021, astronomers A. Berdeu, M. Langlois, and F. Vachier reported the discovery of a third, closer-in satellite in archival VLT-SPHERE images taken between 9 and 31 December 2014, making Elektra the first quadruple system discovered and imaged in the main asteroid belt. This third satellite does not have an officially assigned provisional designation, but is sometimes unofficially called "Delta" or "S/2014 (130) 2". It had eluded discovery when the images were taken, due to its faintness and close proximity to Elektra's bright glare. For these reasons, it had to be measured through image subtraction of Elektra's glare. The satellite measures roughly 1.6 km mi 1 in diameter, based on a near-infrared magnitude difference of 10.5. The satellite has been identified in later VLT images from February 2016 and July–August 2019. With a semi-major axis of 344 km mi and an orbital period of 0.68 d h, it is the innermost companion of the Elektra system. In contrast to the two outer satellites, its orbit is remarkably eccentric and inclined; it has a high eccentricity of 0.33 and an inclination about 38° with respect to Elektra's spin axis (129° with respect to the celestial equator). The satellite's close proximity to Elektra makes its orbit subject to perturbations by shape-induced irregularities in Elektra's gravitational field (see geopotential model), which may account for most of the uncertainties in its Keplerian orbit. Notes References 22em 130 Elektra (A873 DA) 2021-06-16 last obs. JPL Small-Body Database Browser https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=130 Jet Propulsion Laboratory 6 November 2021 https://web.archive.org/web/20210502171013/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000130 live 2 May 2021 (130) Elektra Minor Planet Center International Astronomical Union http://www.minorplanetcenter.net/db_search/show_object?object_id=130 6 November 2021 Asteroid 130 Elektra Small Bodies Data Ferret Planetary Science Institute / International Astronomical Union https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=130+Elektra 6 November 2021 7 November 2021 https://web.archive.org/web/20211107011838/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=130+Elektra dead 130 6 November 2021 Johnston Wm. Robert 11 November 2021 (130) Elektra, S/2003 (130) 1, S/2014 (130) 1, 'and third companion Asteroids with Satellites Database http://www.johnstonsarchive.net/astro/astmoons/am-00130.html 11 November 2021 Johnston's Archive Lutz D. Schmadel August 2003 Dictionary of Minor Planet Names (130) Elektra Springer Berlin Heidelberg 1 27 9783540002383 https://books.google.com/books?id=VoJ5nUyIzCsC&q=elektra Daniel W. E. Green 17 August 2003 IAUC 8183: S/2003 (130) 1; 2003hd; C/2003 E1; C/2002 Y1; Corr International Astronomical Union Circular 8183 1 Central Bureau for Astronomical Telegrams 2003IAUC.8183....1M http://www.cbat.eps.harvard.edu/iauc/08100/08183.html#Item1 Elektra: A new triple asteroid 25 April 2016 European Southern Observatory http://www.eso.org/public/images/potw1617a/ 9 May 2016 Daniel W. E. Green 6 November 2021 (130) Elektra Electronic Telegram Central Bureau for Astronomical Telegrams International Astronomical Union http://www.cbat.eps.harvard.edu/iau/cbet/005000/CBET005066.txt 6 November 2021 E.F. Tedesco P.V. Noah M. Noah S.D. Price October 2004 IRAS Minor Planet Survey v6.0 NASA Planetary Data System Planetary Science Institute / NASA IRAS-A-FPA-3-RDR-IMPS-V6.0 2004PDSS...12.....T https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab 6 November 2021 F. Marchis M. Kaasalainen E.F.Y. Hom J. Berthier J. Enriquez D. Hestroffer D. Le Mignant I. de Pater etal November 2006 Shape, size, and multiplicity of main-belt asteroids: I. Keck Adaptive Optics survey Icarus 185 1 39–63 19081813 10.1016/j.icarus.2006.06.001 2006Icar..185...39M 2600456 37475382 https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC2600456&blobtype=pdf https://web.archive.org/web/20221006214801/https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC2600456&blobtype=pdf 6 October 2022 7 November 2021 dead J. Ďurech M. Kaasalainen A. Marciniak W.H. Allen R. Behrend C. Bembrick etal April 2007 Physical models of ten asteroids from an observers' collaboration network Astronomy & Astrophysics 465 1 331–337 10.1051/0004-6361:20066347 free 2007A&A...465..331D 123543208 https://www.aanda.org/articles/aa/pdf/2007/13/aa6347-06.pdf F. Marchis P. Descamps J. Berthier D. Hestroffer F. Vachier M. Baek A.W. Harris D. Nesvorný May 2008 Main belt binary asteroidal systems with eccentric mutual orbits Icarus 195 1 295–316 10.1016/j.icarus.2007.12.010 119244052 0804.1385 2008Icar..195..295M B. Yang Z. Wahhaj L. Beauvalet F. Marchis C. Dumas M. Marsset E.L. Nielsen F. Vachier August 2016 Extreme AO observations of two triple-asteroid systems with SPHERE The Astrophysical Journal Letters 820 2 6 L35 10.3847/2041-8205/820/2/L35 free 1603.04435 2016ApJ...820L..35Y 118585139 J. Hanuš F. Marchis M. Viikinkoski B. Yang M. Kaasalainen March 2017 Shape model of asteroid (130) Elektra from optical photometry and disk-resolved images from VLT/SPHERE and Nirc2/Keck Astronomy & Astrophysics 599 7 10.1051/0004-6361/201629592 free A36 1611.03632 2017A&A...599A..36H 22881490 https://www.aanda.org/articles/aa/pdf/2017/03/aa29592-16.pdf R. Miles A. Pratt T. Haymes June 2018 Stellar occultation by asteroid (130) Elektra successfully observed across Europe Journal of the British Astronomical Association 128 3 132–133 2018JBAA..128..132M http://cdsads.u-strasbg.fr/pdf/2018JBAA..128..132M D.W. Dunham J.B. Dunham J. Broughton F. Frappa S. Preston T. George January 2019 Paver Mounts allow mapping Elektra's profile from North Carolina, 2018 May 1 Journal for Occultation Astronomy 9 1 3–8 2019JOA.....9a...3D 0737-6766 https://iota-es.de/JOA/JOA2019_1.pdf P. Vernazza M. Ferrais L. Jorda J. Hanuš B. Carry M. Marsset etal October 2021 VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis Astronomy & Astrophysics 654 48 10.1051/0004-6361/202141781 free 2021A&A...654A..56V 239104699 A56 https://www.aanda.org/articles/aa/pdf/2021/10/aa41781-21.pdf Anthony Berdeu Maud Langlois Frédéric Vachier February 2021 First observation of a quadruple asteroid. Detection of a third moon around (130) Elektra with SPHERE/IFS Astronomy & Astrophysics 658 21 10.1051/0004-6361/202142623 free 2202.04425 2022A&A...658L...4B L4 https://www.aanda.org/articles/aa/pdf/2022/02/aa42623-21.pdf G. Valvano R. Machado Oliveira O. C. Winter R. Sfair G. Borderes-Motta May 2023 (130) Elektra Delta – on the stability of the new third moonlet Monthly Notices of the Royal Astronomical Society 522 4 6196–6202 10.1093/mnras/stad1322 free 2304.14967 2023MNRAS.522.6196V External links First observation of a quadruple asteroid - Detection of a third moon around (130) Elektra, Anthony Berdeu, YouTube, 10 February 2022 (video presentation on the third satellite discovery) 130 Elektra and S/2003 (130) 1, orbit data website maintained by F. Marchis. Includes adaptive optics image of primary, and satellite orbit diagram. Data on (130) Elektra from Johnston's archive (maintained by W. R. Johnston) Occultation Prediction Software (David Herald) 130 129 Antigone 130 131 Vala 000130 Category:Discoveries by Christian Peters Category:Named minor planets 000130 000130 000130 18730217