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2684 Douglas (1981 AH1)
Classification: Main-belt Asteroid          SPK-ID: 2002684
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 40 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .0477489798427727 3.3475e-08  
a 3.052571099312674 1.6032e-08 au
q 2.906813943422963 1.0623e-07 au
i 9.932901862490247 4.1562e-06 deg
node 150.6704050376607 2.3256e-05 deg
peri 111.379107752379 5.2663e-05 deg
M 48.35314212847208 4.6666e-05 deg
tp 2458938.850861340020
(2020-Mar-30.35086134)
0.0002527 TDB
period 1948.036586067652
5.33
1.5347e-05
4.202e-08
d
yr
n .1848014573107704 1.4559e-09 deg/d
Q 3.198328255202385 1.6798e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2426  
   data-arc span      22196 days (60.77 yr)  
   first obs. used      1960-02-27  
   last obs. used      2020-12-04  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .42762  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 01:04:49  

Additional Information
 Earth MOID = 1.90774 au 
 Jupiter MOID = 1.88873 au 
 T_jup = 3.212 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456688.5 (2014-Jan-31.0) TDB
Reference: JPL 40 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04451328799000291 3.3727e-08  
q 2.912792666642698 1.0592e-07 au
tp 2457001.573031449002
(2014-Dec-10.07303145)
0.00027175 TDB
node 150.7883816624689 2.3321e-05 deg
peri 112.8176388509869 5.5634e-05 deg
i 9.920376863525034 4.152e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2426  
   data-arc span      22196 days (60.77 yr)  
   first obs. used      1960-02-27  
   last obs. used      2020-12-04  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .42762  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 01:04:49  

Additional Information
 Jupiter MOID = 1.88873 au 
 T_jup = 3.212 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.137491950244129E-15 -3.538377770696316E-15 -5.262201459905064E-13 1.494272954279788E-15 -9.156503296990923E-14 4.42082570271506E-17
q -3.538377770696316E-15 1.121802586979116E-14 9.068473451977828E-13 -4.439522466011222E-15 1.419699809876138E-13 1.34593710240149E-15
tp -5.262201459905064E-13 9.068473451977828E-13 7.384809085152035E-8 -2.459286794896851E-11 1.374835647411976E-8 -3.704264771038847E-12
node 1.494272954279788E-15 -4.439522466011222E-15 -2.459286794896851E-11 5.438680376332196E-10 -5.398836657630077E-10 1.661156106234237E-11
peri -9.156503296990923E-14 1.419699809876138E-13 1.374835647411976E-8 -5.398836657630077E-10 3.095119885071364E-9 -1.69808876668802E-11
i 4.42082570271506E-17 1.34593710240149E-15 -3.704264771038847E-12 1.661156106234237E-11 -1.69808876668802E-11 1.723921740241252E-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 11.68   n/a E2021B10  
diameter diameter 15.962 km 0.255 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.159   0.008 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

2684 Douglas (1981 AH1)          Discovered 1981-Jan-03 by Thomas, N. G. at Flagstaff (AM)
Discovered at the Anderson Mesa station, which is operated by the Lowell Observatory.
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 1981 AH1 = 1960 DE = 1972 NY = 1978 PO2 = 1978 RU4 = 1978 SE4 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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