1656 Suomi
Asteroid
1656 Suomi (prov. designation : 1942 EC ) is a binary Hungaria asteroid and sizable Mars-crosser from the innermost regions of the asteroid belt . It was discovered on 11 March 1942, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland,[ 3] who named it "Suomi", the native name of Finland .[ 2] The stony asteroid has a short rotation period of 2.6 hours and measures approximately 7.9 kilometers in diameter. In June 2020, a companion was discovered by Brian Warner , Robert Stephens and Alan Harris .[ 6] The satellite measures more than 1.98 kilometers in diameter, about 26% of the primary, which it orbits once every 57.9 hours at an average distance of 30 kilometers.[ 4] [ 5]
Orbit and classification
Suomi is a member of the Hungaria family , which form the innermost 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 an eccentricity of 0.12 and an inclination of 25° with respect to the ecliptic .[ 1]
It is also classified as a Mars-crossing asteroid, since its perihelion – 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 ' s observation arc begins on the preceding night of its discovery, with an observation taken at Johannesburg Observatory on 10 March 1942.[ 3]
Naming
As with 1453 Fennia , this minor planet was named after Finland (Finnish : Suomi ).[ 2] The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3932 ).[ 20]
Physical characteristics
In the Tholen taxonomy, Suomi is a stony S-type asteroid .[ 1]
Diameter and albedo
According to the survey carried out by the Infrared Astronomical Satellite IRAS , Suomi measures 7.86 kilometers in diameter and its surface has an albedo of 0.156,[ 7] making it one of the largest Mars crossing asteroid with a known diameter.[ 21] The Collaborative Asteroid Lightcurve Link (CALL) agrees with IRAS, and adopts an albedo of 0.157 and a diameter of 7.9 kilometers with an absolute magnitude of 13.146.[ 5]
Rotation period
Since 1991, a large number of rotational lightcurves of Suomi have been obtained from photometric observations (also see infobox) . CALL adopts a rotation period of 2.583 hours with a brightness variation of 0.20 magnitude (U=3 ).[ 5]
References
^ a b c d e f g "JPL Small-Body Database Browser: 1656 Suomi (1942 EC)" (2017-06-06 last obs.). Jet Propulsion Laboratory . Retrieved 30 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 . Retrieved 24 December 2016 .
^ a b Johnston, Robert (11 October 2020). "(1656) Suomi" . johnstonsarchive.net. Retrieved 24 October 2020 .
^ a b c d e f "LCDB Data for (1656) Suomi" . Asteroid Lightcurve Database (LCDB). Retrieved 24 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 . Retrieved 22 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 December 2016 .
^ Behrend, Raoul. "Asteroids and comets rotation curves – (1656) Suomi" . Geneva Observatory . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 24 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 . Retrieved 26 May 2015 .
External links
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 (2009)
Asteroid Lightcurve Database (LCDB) , query form (info Archived 16 December 2017 at the Wayback Machine )
Dictionary of Minor Planet Names , Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
1656 Suomi at AstDyS-2, Asteroids—Dynamic Site
1656 Suomi at the JPL Small-Body Database