Trojan asteroid
1647 Menelaus /m ɛ n ə ˈ l eɪ ə s / is a mid-sizedJupiter trojan from theGreek camp , approximately 42 kilometers (26 miles) in diameter. It was discovered on 23 June 1957 by American astronomerSeth Nicholson at thePalomar Observatory in California and later named after the Spartan KingMenelaus from Greek mythology.[ 1] [ 3] The darkasteroid has arotation period of 17.7 hours.[ 9] It is the principal body of the proposedMenelaus cluster , which encompasses several, mostly tentative Jovianasteroid families .
Orbit and classification [ edit ] Menelaus is a dark Jovianasteroid in a 1:1orbital resonance with Jupiter. It is located in the leadingGreek camp at the Gas Giant'sL4 Lagrangian point , 60° ahead of its orbit(seeTrojans in astronomy ) . Since the discovery of the first Jupiter trojan,588 Achilles , by astronomerMax Wolf in 1906, more than 7000 Jovian asteroids have already been discovered.[ 5]
It orbits the Sun at a distance of 5.1–5.3 AU once every 11 years and 11 months (4,347 days;semi-major axis of 5.21 AU). Its orbit has aneccentricity of 0.02 and aninclination of 6° concerning theecliptic .[ 4] Menelaus was first imaged at Palomar in November 1951. Thisprecovery extends the body'sobservation arc by more than 5 years before its official discovery observation.[ 1]
In 1993,Andrea Milani suggested thatMenelaus might be theparent body of anasteroid family based on a modifiedHCM-analysis .[ 11] : 78 The finding was also mentioned byDavid Jewitt in 2004,[ 12] : 12 who noted that theMenelaus family is the largest proposed dynamic family to exist among the Jupiter trojans, despite having only eight members.[ a]
In 2008,Fernando Roig andRicardo Gil-Hutton described this particular aggregation of Jupiter trojans as the "Menelaus clan," which, similar to theFlora family in the inner asteroid belt, is composed of several families (or subfamilies).[ 13] : 9 In this publication, the Menelaus clan encompasses a dozen clusters if the separation criteria used in the HCM analysis are sufficiently relaxed. The principal bodies of these proposed family-like clusters include: 1647 Menelaus,3548 Eurybates ,1749 Telamon ,12973 Melanthios ,13062 Podarkes ,5436 Eumelos ,2148 Epeios ,4007 Euryalos ,4138 Kalchas ,3063 Makhaon and others.[ 13] : 10
Except for theEurybates family , which was studied in more detail by Jakub Rozehnal and Miroslav Brož in 2011(also see3548 Eurybates § Eurybates family ) , all other proposed families with their principal bodies in the Menelaus clan, includingMenelaus itself,[ 6] are tentative and not listed neither on the Asteroids—Dynamic Site (Milani and Knežević) nor included in the robust HCM-analysis by Nesvorný(also seeAsteroid family § All families ) .[ 14] : 23 Instead, these bodies are considered non-family asteroids of theJovian background population .
Thisminor planet was named after the Greek mythological figure,Menelaus , husband ofHelen of Troy , brother ofAgamemnon , and king and leader of theSpartan contingent of the Greek army during theTrojan War . The discoverer followed the convention to name bodies located in the camp to the east of Jupiter after famous Greek heroes.
TheDictionary of Minor Planet Names also mentions that thelunar craterMenelaus was named after the Greek hero.[ 3] However, based on the official International Astronomical Union–WGPSN nomenclature, it is named after Greek geometer and astronomerMenelaus of Alexandria (70–140).[ 15] The officialnaming citation was published by theMinor Planet Center in June 1960 (M.P.C. 2019 ).[ 16]
Physical characteristics [ edit ] Menelaus is an assumedC-type , while most larger Jupiter trojans areD-type asteroids . It has aV–I color index of 0.866.[ 9] [ 10]
ThePalomar Transient Factory in California obtained a rotationallight curve ofMenelaus from photometric observation in the R-band in October 2010. It gave arotation period of 17.7390 hours with a brightness variation of 0.32magnitude in the R-band (U=2 ).[ 9] [ 17] In February 2014, a refined period of 17.74± 0.01 hours with an amplitude of 0.15 magnitude was determined by American astronomerRobert D. Stephens at theCenter for Solar System Studies (U=3- ).[ 8] [ b]
Diameter and albedo [ edit ] According to the survey by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Menelaus measures 42.72 kilometers in diameter, and its surface has analbedo of 0.056.[ 7] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 44.22 kilometers using anabsolute magnitude of 10.5.[ 9]
100+ largest Jupiter trojans
^ Members of the Menelaus cluster identified by Milani in 1993 are1749 Telamon ,3548 Eurybates ,(6053) 1993 BW3 ,6076 Plavec ,(6002) 1988 RO ,6051 Anaximenes and6006 Anaximandros , some of which are main-belt or Amor asteroids (Milani 1993, p. 94 ). Besides theMenelaus family , Milani found four other potential families in theGreek camp , clustered around the Jovian asteroids1437 Diomedes ,2456 Palamedes ,2797 Teucer and(4035) 1986 WD , as well as the asteroid pair1583 Antilochus —3801 Thrasymedes . ^ Lightcurve plots of (1647) Menelaus fromJan–Feb 2014 byRobert Stephens at the Center for Solar System Studies (U81 ). Quality code is 3- (lightcurve rating at CS3). Summary figures at theLCDB andCS3 . ^a b c d e "1647 Menelaus (1957 MK)" .Minor Planet Center . Retrieved22 June 2018 .^ Noah Webster (1884)A Practical Dictionary of the English Language ^a b c Schmadel, Lutz D. (2007). "(1647) Menelaus".Dictionary of Minor Planet Names .Springer Berlin Heidelberg . p. 131.doi :10.1007/978-3-540-29925-7_1648 .ISBN 978-3-540-00238-3 . ^a b c d "JPL Small-Body Database Browser: 1647 Menelaus (1957 MK)" (2017-06-03 last obs.).Jet Propulsion Laboratory . Retrieved22 June 2018 .^a b "List of Jupiter Trojans" .Minor Planet Center . 1 June 2018. Retrieved22 June 2018 .^a b "Asteroid (1647) Menelaus – Proper Elements" . AstDyS-2, Asteroids – Dynamic Site. Retrieved22 June 2018 .^a b c Grav, T.; Mainzer, A. K.; Bauer, J. M.; Masiero, J. R.; Nugent, C. R. (November 2012)."WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy" .The Astrophysical Journal .759 (1): 10.arXiv :1209.1549 .Bibcode :2012ApJ...759...49G .doi :10.1088/0004-637X/759/1/49 .S2CID 119101711 . Retrieved22 June 2018 . (Grav (2012) Grav (2011) )^a b Stephens, Robert D.; Coley, Daniel R.; Warner, Brian D.; French, Linda, M. (October 2016)."Lightcurves of Jovian Trojan Asteroids from the Center for Solar System Studies: L4 Greek Camp and Spies" .The Minor Planet Bulletin .43 (4):323– 331.Bibcode :2016MPBu...43..323S .ISSN 1052-8091 . Retrieved22 June 2018 . {{cite journal }}: CS1 maint: multiple names: authors list (link )^a b c d e f "LCDB Data for (1647) Menelaus" . Asteroid Lightcurve Database (LCDB). Retrieved27 December 2016 .^a b c Hainaut, O. R.; Boehnhardt, H.; Protopapa, S. (October 2012). "Colours of minor bodies in the outer solar system. II. A statistical analysis revisited".Astronomy and Astrophysics .546 : 20.arXiv :1209.1896 .Bibcode :2012A&A...546A.115H .doi :10.1051/0004-6361/201219566 .S2CID 54776793 . ^ Milani, Andrea (October 1993)."The Trojan asteroid belt: Proper elements, stability, chaos and families" .Celestial Mechanics and Dynamical Astronomy .57 (1– 2):59– 94.Bibcode :1993CeMDA..57...59M .doi :10.1007/BF00692462 .ISSN 0923-2958 .S2CID 189850747 . Retrieved13 April 2017 . ^ Jewitt, David C.; Sheppard, Scott; Porco, Carolyn C. (2004)."Jupiter's Outer Satellites and Trojans – 12.4.2 Families" (PDF) . In Bagenal, Fran; Dowling, Timothy E.; McKinnon, William B. (eds.).Jupiter: The planet, Satellites and Magnetosphere .Cambridge University Press . p. 12. Retrieved13 April 2017 . ^a b Roig, F.; Ribeiro, A. O.; Gil-Hutton, R. (June 2008). "Taxonomy of asteroid families among the Jupiter Trojans: comparison between spectroscopic data and the Sloan Digital Sky Survey colors".Astronomy and Astrophysics .483 (3):911– 931.arXiv :0712.0046 .Bibcode :2008A&A...483..911R .doi :10.1051/0004-6361:20079177 .S2CID 118361725 . ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families".Asteroids IV . pp. 297– 321.arXiv :1502.01628 .Bibcode :2015aste.book..297N .doi :10.2458/azu_uapress_9780816532131-ch016 .ISBN 9780816532131 .S2CID 119280014 . ^ "Gazetteer of Planetary Nomenclature – Planetary Names: Crater, craters: Menelaus on Moon" .International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN) . Retrieved27 December 2016 .^ Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs".Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) . Springer Berlin Heidelberg. p. 221.Bibcode :2009dmpn.book.....S .doi :10.1007/978-3-642-01965-4 .ISBN 978-3-642-01964-7 . ^ Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry".The Astronomical Journal .150 (3): 35.arXiv :1504.04041 .Bibcode :2015AJ....150...75W .doi :10.1088/0004-6256/150/3/75 .S2CID 8342929 .