+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   7174 Semois (1988 SQ) Classification: Outer Main-belt Asteroid          SPK-ID: 2007174 [ 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 33 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1759174901945681 2.3754e-08   a 3.993366985241571 3.1604e-08 au q 3.290863887772025 9.9675e-08 au i 12.65035984397954 1.1267e-06 deg node 354.358719596135 8.6323e-06 deg peri 290.1510962807532 1.0824e-05 deg M 86.99806760876592 9.0167e-06 deg tp 2458692.108077666668 (2019-Jul-27.60807767) 7.3345e-05 TDB period 2914.789937408319 7.98 3.4602e-05 9.474e-08 d yr n .1235080426825177 1.4662e-09 deg/d Q 4.695870082711117 3.7163e-08 au   Orbit Determination Parameters    # obs. used (total)      2459      data-arc span      24067 days (65.89 yr)      first obs. used      1955-03-24      last obs. used      2021-02-12      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .40597      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 19:28:22   Additional Information  Earth MOID = 2.3048 au   Jupiter MOID = .994249 au   T_jup = 2.986  [ 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 11.75   n/a E2021B10   diameter diameter 25.526 km 0.328 urn:nasa:pds:neowise_diameters_albedos::2.0[hildas] (http://adsabs.harvard.edu/abs/2012ApJ...744..197G)   rotation period rot_per 7.456 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: [Warner, B.D.; Stephens, R.D. (2017) Minor Planet Bull. 44, 331-334.] [Warner, B.D.; Stephens, R.D. (2021) Minor Planet Bull. 48-1, submitted. (Hilda) http://www.planetarysciences.org/lightcurves.html] geometric albedo albedo 0.074   0.011 urn:nasa:pds:neowise_diameters_albedos::2.0[hildas] (http://adsabs.harvard.edu/abs/2012ApJ...744..197G)   7174 Semois           Discovered 1988 Sept. 18 by H. Debehogne at the European Southern Observatory. The Semois, a river in Wallonia, rises near the city of Arlon, Luxembourg. It flows from the Ardennes to the river Meuse. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20081113/MPCPages.arc Last Updated: 2008-11-17 Alternate Designations  1988 SQ = 1980 RH3  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Aug-10 17:01 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin