+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21655 Niklauswirth (1999 PC1) Classification: Main-belt Asteroid          SPK-ID: 2021655 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 35 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1804253429702663 1.8158e-08   a 2.642487965756149 1.0636e-08 au q 2.165716168239795 4.5536e-08 au i 13.42983165499005 9.1007e-07 deg node 293.3186083874128 3.5126e-06 deg peri 7.333495706412605 8.8488e-06 deg M 112.9715135678476 6.7692e-06 deg tp 2458904.138143347135 (2020-Feb-24.63814335) 2.8707e-05 TDB period 1568.981974279558 4.30 9.4723e-06 2.593e-08 d yr n .229448142745747 1.3852e-09 deg/d Q 3.119259763272504 1.2555e-08 au   Orbit Determination Parameters    # obs. used (total)      2271      data-arc span      10675 days (29.23 yr)      first obs. used      1991-12-28      last obs. used      2021-03-20      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .40377      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 18:36:00   Additional Information  Earth MOID = 1.15017 au   Jupiter MOID = 2.11171 au   T_jup = 3.333  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.34   n/a MPCxxxxx   diameter diameter 6.609 km 0.105 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   rotation period rot_per 18.8016 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.] geometric albedo albedo 0.194   0.017 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   21655 Niklauswirth           Discovered 1999 Aug. 8 by L. Šarounová at Ondřejov. Niklaus Wirth (b. 1934), professor of computer science variously at Stanford University, the University of Zurich and the Swiss Federal Institute of Technology, Zurich, created the computer languages ALGOL, Pascal and Modula. His ideas are widely used in the architecture of contemporary computer systems. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20010902/MPCPages.arc Last Updated: 2009-05-11 Alternate Designations  1999 PC1 = 1998 MC27  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-31 07:23 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin