+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   363027 (1998 ST27) Classification: Aten [NEO, PHA]          SPK-ID: 2363027 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 86 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .5299847367577882 1.414e-07   a .8193631748252406 4.2256e-09 au q .3851131983064598 1.1413e-07 au i 21.06000330788257 1.1122e-05 deg node 197.5421090407871 5.6387e-06 deg peri 322.4698210971581 7.4021e-06 deg M 216.8475971540329 2.0101e-05 deg tp 2459308.223196077423 (2021-Apr-03.72319608) 1.582e-05 TDB period 270.9025473334185 0.74 2.0957e-06 5.738e-09 d yr n 1.328891158623633 1.028e-08 deg/d Q 1.253613151344021 6.4652e-09 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A2 [EST] 2.029333891966252E-14 3.895E-15 ALN [SET] 1. n/a NK [SET] 0. n/a NM [SET] 2. n/a R0 [SET] 1. n/a   Orbit Determination Parameters    # obs. used (total)      407      # delay obs. used      6      # Doppler obs. used      1      data-arc span      7309 days (20.01 yr)      first obs. used      1998-09-24      last obs. used      2018-09-28      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .38028      source      ORB      producer      Otto Matic      solution date      2021-Apr-14 09:41:47   Additional Information  Earth MOID = .00943652 au   Jupiter MOID = 3.76278 au   T_jup = 6.979   Nongravitational accels. using nonstandard g(r) = (1 au/ r)^2  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 19.5   n/a MPO260882   diameter diameter 0.578 km 0.228 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   rotation period rot_per 3. 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: [Benner, L.A.M.; Nolan, M.C.; Ostro, S.J.; Giorgini, J.D.; Margot, J.-L. (2001) IAUC 7730.] geometric albedo albedo 0.059   0.066 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   363027 (1998 ST27)          Discovered 1998-Sep-24 by LINEAR at Socorro Reference: Last Updated: 2013-06-26 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-May-14 17:54 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin