1446 Sillanpää

Stony Florian asteroid October 2019 yes 1446 Sillanpää #D6D6D6 File:001446-asteroid shape model (1446) Sillanpää.png Shape of Sillanpää modelled from its lightcurve 26 January 1938 Y. Väisälä Turku Obs. (1446) Sillanpaa 1938 BA1935 GB1952 HQ 31955 DQ1965 EA Frans Sillanpää (writer) main-beltFlora 16 February 2017 (JD 2457800.5) 0 78.53 yr (28,683 days) 2.4732 AU 2.0179 AU 2.2455 AU 0.1014 3.37 yr (1,229 days) 98.112° 0.2929 ms / day 5.2572° 17.549° 196.25° 7.35 0.29 km8.167 0.154 km8.19 km (calculated)8.763 0.063 km 9.65855 0.00005 h9.659 0.001 h9.6597 0.0172 h9.6602 0.0008 hLCDB-Pravec-2009 0.2109 0.01080.24 (assumed)0.241 0.0460.327 0.080 S 12.394 0.002 (R)12.5012.6 1446 Sillanpää, provisional designation 1938 BA, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8.2 kilometers in diameter. It was discovered on 26 January 1938, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland. It was later named after writer Frans Eemil Sillanpää. Orbit and classification The S-type asteroid is a member of the Flora family, one of the largest populations of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,229 days). Its orbit has an eccentricity of 0.10 and an inclination of 5° with respect to the ecliptic. Sillanpää was first identified as 1935 GB at Simeiz Observatory in 1935, while its observation arc begins with its official discovery observation at Turku in 1938. Lightcurves In March 2009, Czech astronomer Petr Pravec obtained a rotational light-curve from photometric observations at Ondřejov Observatory.Light-curve-analysis It gave a well-defined rotation period of 9.6602 hours with a brightness variation of 0.55 magnitude (U=3).LCDB-Pravec-2009 One month later, a concurring period of 9.659 hours with an amplitude of 0.71 magnitude was obtained by Adrián Galád at Modra Observatory (U=3). Photometric observations at the Palomar Transient Factory in December 2011. gave a 9.6597 hours and Δ0.59 in magnitude (U=2). A modeled light-curve using data from the Uppsala Asteroid Photometric Catalogue and other data sources, gave a period of 9.65855 hours, as well as a spin axis of (129.0°, 76.0°) in ecliptic coordinates (U=n.a.). Diameter and albedo According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sillanpää measures between 7.35 and 8.76 kilometers in diameter, and its surface has an albedo between 0.21 and 0.327. The Collaborative Asteroid Lightcurve Link assumes an intermediate albedo of 0.24 – derived from 8 Flora, the largest member and namesake of this asteroid family – and calculates a larger diameter of 8.19 kilometers using an absolute magnitude of 12.6. Naming This minor planet was named after one of the most famous Finnish writers, Frans Eemil Sillanpää (1888–1964), first Finnish writer to receive the Nobel Prize in Literature in 1939 (also see List of Laureates since 1901). The official 1446 naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3928). References LCDB-Pravec-2009 Pravec (2009) web: rotation period 9.6602 0.0008 hours with a brightness amplitude of 0.55 mag. Summary figures at http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1446%7CSillanpaa Collaborative Asteroid Lightcurve Link (CALL) for (1446) Sillanpaa and http://www.asu.cas.cz/~ppravec/neo.htm Pravec, P.; Wolf, M.; Sarounova, L. (2009) Light-curve-analysis Light-curve analysis: http://www.asu.cas.cz/~asteroid/01446.png screenshot 2016-08-07 last obs. JPL Small-Body Database Browser: 1446 Sillanpaa (1938 BA) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001446 Jet Propulsion Laboratory 4 January 2017 Dictionary of Minor Planet Names – (1446) Sillanpää Schmadel Lutz D. Springer Berlin Heidelberg 116 2007 978-3-540-00238-3 10.1007/978-3-540-29925-7_1447 (1446) Sillanpää 1446 Sillanpaa (1938 BA) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=1446 4 January 2017 Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) 2009 https://archive.org/details/dictionaryminorp2008schm limited Appendix – Publication Dates of the MPCs Schmadel Lutz D. Springer Berlin Heidelberg 221 978-3-642-01964-7 10.1007/978-3-642-01965-4 6 Joseph R. Masiero T. Grav A. K. Mainzer C. R. Nugent J. M. Bauer R. Stevenson S. Sonnett August 2014 Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M The Astrophysical Journal 791 2 11 2014ApJ...791..121M 10.1088/0004-637X/791/2/121 1406.6645 4 January 2017 1446 4 January 2017 6 A. Mainzer T. Grav J. Masiero E. Hand J. Bauer D. Tholen R. S. McMillan T. Spahr R. M. Cutri E. Wright J. Watkins W. Mo C. Maleszewski November 2011 NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results The Astrophysical Journal 741 2 25 2011ApJ...741...90M 10.1088/0004-637X/741/2/90 1109.6407 6 Joseph R. Masiero A. K. Mainzer T. Grav J. M. Bauer R. M. Cutri C. Nugent M. S. Cabrera November 2012 Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M The Astrophysical Journal Letters 759 1 5 2012ApJ...759L...8M 10.1088/2041-8205/759/1/L8 1209.5794 4 January 2017 Galad, Adrian October 2009 Byproduct Targets During Photometric Observations from Modra http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2009MPBu...36..183G The Minor Planet Bulletin 36 4 183–186 1052-8091 2009MPBu...36..183G 4 January 2017 6 J. Hanus M. Broz J. Durech B. D. Warner J. Brinsfield R. Durkee D. Higgins R. A. Koff J. Oey F. Pilcher R. Stephens L. P. Strabla Q. Ulisse R. Girelli November 2013 An anisotropic distribution of spin vectors in asteroid families http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013A&A...559A.134H Astronomy and Astrophysics 559 19 2013A&A...559A.134H 10.1051/0004-6361/201321993 1309.4296 4 January 2017 6 Adam Waszczak Chan-Kao Chang Eran O. Ofek Russ Laher Frank Masci David Levitan Jason Surace Yu-Chi Cheng Wing-Huen Ip Daisuke Kinoshita George Helou Thomas A. Prince Shrinivas Kulkarni September 2015 Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W The Astronomical Journal 150 3 35 2015AJ....150...75W 10.1088/0004-6256/150/3/75 1504.04041 4 January 2017 External links Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR https://web.archive.org/web/20160729213840/http://obswww.unige.ch/~behrend/page_cou.html 29 July 2016 – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 1446 1445 Konkolya 1446 1447 Utra 001446 Category:Discoveries by Yrjö Väisälä Category:Named minor planets 19380126