1990 Pilcher

Stony main-belt asteroid March 2018 yes 1990 Pilcher #D6D6D6 K. Reinmuth Heidelberg Obs. 9 March 1956 (1990) Pilcher 1956 EE1937 JL1940 FA1959 CE 11964 VS 21972 EC1972 GO1973 QM Frederick Pilcher(American photometrist) main-belt(inner)backgroundFlora 23 March 2018 (JD 2458200.5) 0 80.17 yr (29,283 d) 2.2851 AU 2.0625 AU 2.1738 AU 0.0512 3.21 yr (1,171 d) 92.884° 0.3075 ms / day 3.1320° 193.63° 11.957° 6.39 km (calculated)6.754 0.167 km7.273 0.064 km 2.842 0.001 h 0.1864 0.02540.215 0.0390.24 (assumed) Tholen SS (assumed)B–V 0.850U–B 0.504 13.14 1990 Pilcher, provisional designation 1956 EE, is a stony background asteroid from the Florian region of the inner asteroid belt, approximately 7 km mi off us in diameter. It was discovered on 9 March 1956, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Heidelberg, Germany. In 1982, it was named by the MPC for American physicist and photometrist Frederick Pilcher. The S-type asteroid has a short rotation period of 2.8 hours. Orbit and classification Pilcher is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method (HCM) to its proper orbital elements (Nesvorný, Milani and Knežević). In a previous HCM-analysis (Zappalà) and based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt. It orbits the Sun in the Florian region of the inner asteroid belt at a distance of 2.1–2.3 AU once every 3 years and 3 months (1,171 days; semi-major axis of 2.17 AU). Its orbit has an eccentricity of 0.05 and an inclination of 3° with respect to the ecliptic. The asteroid was first observed as 1937 JL at Nice Observatory in May 1937. The body's observation arc begins with a precovery taken at Palomar Observatory in June 1950, or six years prior to its official discovery observation at Heidelberg. Physical characteristics In the Tholen classification, Pilcher is a common, stony S-type asteroid. Rotation period In March 2017, a first rotational lightcurve of Pilcher was obtained from photometric observations at the Flarestar Observatory on the island of Malta. Lightcurve analysis gave a short rotation period of 2.842 hours with a brightness amplitude of 0.10 magnitude, indicative for a rather spherical shape (U=2+). Diameter and albedo According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Pilcher measures between 6.754 and 7.273 kilometers in diameter and its surface has an albedo between 0.1864 and 0.215. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the Flora family's parent body and namesake – and calculates a diameter of 6.39 kilometers based on an absolute magnitude of 13.14. Naming This minor planet was named after American astronomer Frederick Pilcher, a retired professor of Physics at Illinois College and prolific lightcurve photometrist at his Organ Mesa Observatory G50 in New Mexico. The official naming citation was published by the Minor Planet Center on 8 April 1982 (M.P.C. 6833). References 30em 2017-07-05 last obs. JPL Small-Body Database Browser: 1990 Pilcher (1956 EE) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001990 Jet Propulsion Laboratory 20 March 2018 1990 Pilcher (1956 EE) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=1990 20 March 2018 MPC/MPO/MPS Archive Minor Planet Center https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html 20 March 2018 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 The Astrophysical Journal 791 2 11 2014ApJ...791..121M 10.1088/0004-637X/791/2/121 1406.6645 Asteroid 1990 Pilcher Small Bodies Data Ferret https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1990+Pilcher 30 May 2018 Small Bodies Data Ferret Nesvorny HCM Asteroid Families V3.0 https://sbntools.psi.edu/ferret/PropertySearch/familyForm.action 30 May 2018 https://web.archive.org/web/20170802210005/http://sbntools.psi.edu/ferret/PropertySearch/familyForm.action 2 August 2017 dead Asteroid (1990) Pilcher AstDyS-2, Asteroids – Dynamic Site https://newton.spacedys.com/astdys/index.php?n=1990&pc=1.1.6 25 May 2018 1990 20 March 2018 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 Stephen M. Brincat Winston Grech October 2017 Photometric Observations of Main-belt Asteroids 1990 Pilcher and 8443 Svecica The Minor Planet Bulletin 44 4 287–288 1052-8091 2017MPBu...44..287B External links Minor Planet Lightcurve Data (Frederick Pilcher) https://web.archive.org/web/20181211081452/http://aslc-nm.org/Pilcher.html 11 December 2018 , Astronomical Society of Las Cruces (ASLC) 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 Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 1990 1989 Tatry 1990 1991 Darwin 001990 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 001990 19560309