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991 McDonalda (A922 UC)
Classification: Main-belt Asteroid          SPK-ID: 2000991
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 48 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1594062530981511 2.9783e-08  
a 3.139360813636149 1.1926e-08 au
q 2.638927069211248 9.8016e-08 au
i 2.069528452069971 3.2436e-06 deg
node 63.23434219130127 8.9605e-05 deg
peri 254.7832608630384 9.0194e-05 deg
M 309.2977616696726 1.1504e-05 deg
tp 2459682.644174010543
(2022-Apr-13.14417401)
6.5557e-05 TDB
period 2031.703254847811
5.56
1.1578e-05
3.17e-08
d
yr
n .1771912306292813 1.0097e-09 deg/d
Q 3.63979455806105 1.3828e-08 au
  Orbit Determination Parameters
   # obs. used (total)      3684  
   data-arc span      31217 days (85.47 yr)  
   first obs. used      1936-02-20  
   last obs. used      2021-08-09  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .42593  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 07:13:40  

Additional Information
 Earth MOID = 1.626 au 
 Jupiter MOID = 1.66413 au 
 T_jup = 3.190 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456882.5 (2014-Aug-13.0) TDB
Reference: JPL 48 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1573045295492741 2.9763e-08  
q 2.647434691259528 9.7774e-08 au
tp 2457649.068152821567
(2016-Sep-17.56815282)
6.2685e-05 TDB
node 63.26281787577346 8.9556e-05 deg
peri 254.6911817263108 9.0164e-05 deg
i 2.069676274223249 3.2427e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      3684  
   data-arc span      31217 days (85.47 yr)  
   first obs. used      1936-02-20  
   last obs. used      2021-08-09  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .42593  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 07:13:40  

Additional Information
 Jupiter MOID = 1.66413 au 
 T_jup = 3.190 
Orbit Covariance (6×6)
  e q tp node peri i
e 8.858167615803307E-16 -2.896982623364567E-15 -5.170647347525524E-14 4.533899566997714E-15 1.392329686432858E-14 -1.088019879755533E-16
q -2.896982623364567E-15 9.559789814610916E-15 3.03365267427599E-13 -2.026479028946254E-14 -2.510288377586993E-14 5.539190778239521E-16
tp -5.170647347525524E-14 3.03365267427599E-13 3.929387800751718E-9 6.04968132051139E-12 6.661756088312597E-10 1.989989300304227E-13
node 4.533899566997714E-15 -2.026479028946254E-14 6.04968132051139E-12 8.020313134709761E-9 -8.013904065384223E-9 -4.623930796443487E-11
peri 1.392329686432858E-14 -2.510288377586993E-14 6.661756088312597E-10 -8.013904065384223E-9 8.129589015872317E-9 4.624461553288509E-11
i -1.088019879755533E-16 5.539190778239521E-16 1.989989300304227E-13 -4.623930796443487E-11 4.624461553288509E-11 1.051524691156614E-11

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 11.26   n/a E2021B10 IRAS observations used: 15
diameter diameter 38.556 km 0.514 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.040   0.005 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
B-V BV 0.660   0.020 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=11.11 deg.
U-B UB 0.370   0.045 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=11.11 deg.
Tholen spectral type spec_T C:   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices

991 McDonalda (A922 UC)          Discovered 1922-Oct-24 by Struve, O. at Williams Bay
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ hide close-approach data ]
Close-Approach Data   ...sorted by Date/Time (TDB)
Date/Time (TDB) Time Uncertainty
(days_HH:MM)
Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified
1907-May-26 05:31 00:02 Jupiter 1.65357065983586 1.65357039913894 1.65357092053268 1.70055346249126 1.36653032574207 2417721.729648464 1.95044007196678 79.5478437852855 28.5879569737019 -63.1696400159642 3309729.87260071 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
1917-Oct-22 07:04 00:02 Jupiter 1.78605942334491 1.78605871500182 1.78606013168801 2.63455625476043 2.44793888135222 2421523.794397322 1.75282862341917 51.0739777270913 7.19619110594235 -80.410768881209 2252656.18086115 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
1991-Aug-21 02:32 < 00:01 Jupiter 1.767664229961 1.76766388982524 1.76766457009657 1.89126402367261 1.61818643553066 2448489.605519733 0.472523391447825 47.841173576408 12.6392819450594 -83.940342548348 3246617.94683484 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2002-Jan-25 20:57 < 00:01 Jupiter 1.66142381395851 1.66142354002268 1.66142408789415 1.79287346264156 1.48147249843591 2452300.372598129 0.277377094674573 42.3204321764957 21.8310363227348 -80.280606777632 3290980.06982618 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2012-Jun-25 03:32 < 00:01 Jupiter 1.85361604308647 1.85361572011925 1.85361636605357 3.02502557456048 2.86999408826874 2456103.647023054 0.173399090185574 29.4819868662499 9.80613052592098 -83.8716686022577 4150452.58318943 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2086-Apr-26 10:07 00:01 Jupiter 1.72791719998419 1.72791673421677 1.72791766575142 1.77716254353045 1.47577423752237 2483071.921534515 1.26590609795027 59.8439704927304 23.6188175794166 86.406748783228 2567245.26569458 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2096-Sep-29 23:13 00:02 Jupiter 1.69545565969099 1.69545534407988 1.69545597530189 1.97746213173034 1.70622052889836 2486881.467381888 1.52292149123112 40.4689451863797 14.1156785962117 -79.278022086995 2865649.58611912 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2107-Mar-01 01:54 00:02 Jupiter 1.93120884433653 1.93120810802928 1.93120958064421 3.4707678363697 3.34201066194968 2490684.579034602 1.70725998903183 66.3248776471011 13.5757007908415 -69.2384646897873 3393975.52532861 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2170-Jul-18 16:49 00:03 Jupiter 1.92392199044728 1.92392085330488 1.92392312759045 2.38904477036425 2.19704766289185 2513835.200951603 2.68749531219042 101.818827741435 9.53204451797775 -79.6128979971929 2399413.23758774 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2180-Dec-29 22:11 00:03 Jupiter 1.69742908712259 1.69742849601242 1.69742967823371 1.71165354483699 1.38987463424948 2517652.424041435 2.95535721152399 113.497636524347 27.0902579266981 87.4524063627661 2911256.03684598 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14
2191-Jun-05 03:19 00:03 Jupiter 1.73838460270687 1.73838385767035 1.7383853477427 2.22089398563191 1.98944120108978 2521461.638511926 3.24924297378375 34.7994958712289 14.5069653791944 -87.201304178034 1181732.5895691 T 48 CATAB v2.0g-lin.ifort 2021-Aug-25 07:14:21 2021-Aug-25 07:14

Alternate Designations
 A922 UC = 1949 PF = 1950 WG = 1953 GT1 = 1975 EE6 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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