Asteroid
1656 Suomi (prov. designation :1942 EC ) is abinary Hungaria asteroid and sizableMars-crosser from the innermost regions of theasteroid belt . It was discovered on 11 March 1942, by Finnish astronomerYrjö Väisälä atTurku Observatory in Southwest Finland,[ 3] Finland .[ 2] stony asteroid has a shortrotation period of 2.6 hours and measures approximately 7.9 kilometers in diameter. In June 2020, acompanion was discovered byBrian Warner ,Robert Stephens andAlan Harris .[ 6] [ 4] [ 5]
Orbit and classification [ edit ] Suomi is a member of theHungaria family , which form theinnermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.6–2.1 AU once every 2 years and 7 months (940 days). Its orbit has aneccentricity of 0.12 and aninclination of 25° with respect to theecliptic .[ 1]
It is also classified as a Mars-crossing asteroid, since itsperihelion – the point in its orbit, where it is nearest to the Sun – is less than the average orbital distance of the planet Mars (1.666 AU).Suomi ' sobservation arc begins on the preceding night of its discovery, with an observation taken atJohannesburg Observatory on 10 March 1942.[ 3]
As with1453 Fennia , this minor planet was named afterFinland (Finnish :Suomi ).[ 2] naming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3932[ 20]
Physical characteristics [ edit ] In theTholen taxonomy,Suomi is a stonyS-type asteroid .[ 1]
Diameter and albedo [ edit ] According to the survey carried out by the Infrared Astronomical SatelliteIRAS ,Suomi measures 7.86 kilometers in diameter and its surface has analbedo of 0.156,[ 7] [ 21] Collaborative Asteroid Lightcurve Link (CALL) agrees with IRAS, and adopts an albedo of 0.157 and a diameter of 7.9 kilometers with anabsolute magnitude of 13.146.[ 5]
Since 1991, a large number of rotationallightcurves ofSuomi have been obtained from photometric observations(also see infobox) . CALL adopts arotation period of 2.583 hours with a brightness variation of 0.20magnitude (U=3 [ 5]
^a b c d e f g "JPL Small-Body Database Browser: 1656 Suomi (1942 EC)" (2017-06-06 last obs.).Jet Propulsion Laboratory . Retrieved30 June 2017 .^a b c Schmadel, Lutz D. (2007). "(1656) Suomi".Dictionary of Minor Planet Names .Springer Berlin Heidelberg . p. 132.doi :10.1007/978-3-540-29925-7_1657 .ISBN 978-3-540-00238-3 ^a b c "1656 Suomi (1942 EC)" .Minor Planet Center . Retrieved24 December 2016 .^a b Johnston, Robert (11 October 2020)."(1656) Suomi" . johnstonsarchive.net. Retrieved24 October 2020 . ^a b c d e f "LCDB Data for (1656) Suomi" . Asteroid Lightcurve Database (LCDB). Retrieved24 December 2016 .^a b Warner, Brian D.; Stephens, Robert D.; Harris, Alan W. (October 2020)."Binary Asteroids at the Center for Solar System Studies" (PDF) .Minor Planet Bulletin 47 (4):305– 308.Bibcode :2020MPBu...47..305W .ISSN 1052-8091 . ^a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004)."IRAS Minor Planet Survey V6.0" .NASA Planetary Data System .12 : IRAS-A-FPA-3-RDR-IMPS-V6.0.Bibcode :2004PDSS...12.....T . Retrieved22 October 2019 . ^a b c d Wisniewski, W. Z.; Michalowski, T. M.; Harris, A. W.; McMillan, R. S. (March 1995)."Photoelectric Observations of 125 Asteroids" .Abstracts of the Lunar and Planetary Science Conference .26 : 1511.Bibcode :1995LPI....26.1511W . Retrieved24 December 2016 . ^ Warner, Brian D. (July 2009)."Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 December - 2009 March" .The Minor Planet Bulletin .36 (3):109– 116.Bibcode :2009MPBu...36..109W .ISSN 1052-8091 . Retrieved24 December 2016 . ^ Warner, Brian D. (October 2012)."Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2012 March - June" .The Minor Planet Bulletin .39 (4):245– 252.Bibcode :2012MPBu...39..245W .ISSN 1052-8091 . Retrieved24 December 2016 . ^ Warner, Brian D. (January 2016)."Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 June-September" .The Minor Planet Bulletin .43 (1):57– 65.Bibcode :2016MPBu...43...57W .ISSN 1052-8091 .PMC 7244003 PMID 32455368 . Retrieved24 December 2016 . ^ Stephens, Robert D. (December 2004)."Photometry of 1196 Sheba, 1341 Edmee, 1656 Suomi, 2577 Litva, and 2612 Kathryn" .The Minor Planet Bulletin .31 (4):95– 97.Bibcode :2004MPBu...31...95S .ISSN 1052-8091 . Retrieved24 December 2016 . ^ Brinsfield, James W. (March 2008)."The Rotation Periods of 1465 Autonoma, 1656 Suomi 4483 Petofi, 4853 Marielukac, and (85275) 1994 LY" .The Minor Planet Bulletin .35 (1):23– 24.Bibcode :2008MPBu...35...23B .ISSN 1052-8091 . Retrieved24 December 2016 . ^ Warner, Brian D. (July 2014)."Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 January-March" .The Minor Planet Bulletin .41 (3):144– 155.Bibcode :2014MPBu...41..144W .ISSN 1052-8091 .PMID 32549049 . Retrieved24 December 2016 . ^ Behrend, Raoul."Asteroids and comets rotation curves – (1656) Suomi" .Geneva Observatory . Retrieved24 December 2016 . ^ Sanchez, Juan A.; Michelsen, René; Reddy, Vishnu; Nathues, Andreas (July 2013)."Surface composition and taxonomic classification of a group of near-Earth and Mars-crossing asteroids" .Icarus .225 (1):131– 140.arXiv :1302.4449 Bibcode :2013Icar..225..131S .CiteSeerX 10.1.1.743.8700 doi :10.1016/j.icarus.2013.02.036 . Retrieved24 December 2016 . ^ Faure, Gerard; Garret, Lawrence (December 2007)."Suggested Revised H Values of Selected Asteroids: Report Number 3" .The Minor Planet Bulletin .34 (4):95– 99.Bibcode :2007MPBu...34...95F .ISSN 1052-8091 . Retrieved24 December 2016 . ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015)."Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results" .Icarus .261 :34– 47.arXiv :1506.00762 Bibcode :2015Icar..261...34V .doi :10.1016/j.icarus.2015.08.007 . Retrieved24 December 2016 . ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012)."Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations" .Icarus .221 (1):365– 387.Bibcode :2012Icar..221..365P .doi :10.1016/j.icarus.2012.07.026 . Retrieved24 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 ^ "JPL Small-Body Database Search Engine: orbital class (MCA) and diameter > 0 (km)" .JPL Solar System Dynamics . Retrieved26 May 2015 .Turun Ursa , (in Finnish)Photometric Observations of 125 Asteroids , Wisniewski,Icarus , Volume 126, Issue 2, pp. 395–449.Lightcurve plot of 1656 Suomi , Palmer Divide Observatory,B. D. Warner Asteroid Lightcurve Database (LCDB) , query form (info Archived 16 December 2017 at theWayback Machine )Dictionary of Minor Planet Names , Google booksAsteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul BehrendDiscovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center1656 Suomi atAstDyS-2, Asteroids—Dynamic Site 1656 Suomi at theJPL Small-Body Database
