Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics
BODIES ORBITS EPHEMERIDES TOOLS PHYSICAL DATA DISCOVERY FAQ SITE MAP

Significant website upgrade scheduled for September 27. More details available here.

JPL Small-Body Database Browser
Search: [ help ]  
21985 Sejna (1999 XG15)
Classification: Main-belt Asteroid          SPK-ID: 2021985
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 25 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1173474995503538 4.357e-08  
a 3.105080524385496 1.9051e-08 au
q 2.740707088946356 1.3249e-07 au
i .7303727939222951 4.712e-06 deg
node 168.9900067046073 0.00026878 deg
peri 11.31414426666285 0.0002693 deg
M 235.4078642000715 1.9843e-05 deg
tp 2460088.165092177783
(2023-May-23.66509218)
0.00011406 TDB
period 1998.516451984161
5.47
1.8393e-05
5.036e-08
d
yr
n .1801336184361084 1.6578e-09 deg/d
Q 3.469453959824635 2.1287e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1249  
   data-arc span      9532 days (26.10 yr)  
   first obs. used      1995-01-07  
   last obs. used      2021-02-11  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .52587  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-13 03:57:01  

Additional Information
 Earth MOID = 1.74466 au 
 Jupiter MOID = 1.48912 au 
 T_jup = 3.210 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457326.5 (2015-Oct-31.0) TDB
Reference: JPL 25 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1147515404556504 4.3986e-08  
q 2.7516243798641 1.3343e-07 au
tp 2458094.110131967655
(2017-Dec-06.61013197)
0.00010497 TDB
node 168.9528530394197 0.00026894 deg
peri 12.39686653987123 0.00026948 deg
i .7293793267559336 4.7126e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      1249  
   data-arc span      9532 days (26.10 yr)  
   first obs. used      1995-01-07  
   last obs. used      2021-02-11  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .52587  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-13 03:57:01  

Additional Information
 Jupiter MOID = 1.48912 au 
 T_jup = 3.210 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.934744064977587E-15 -5.824004753177597E-15 -1.059050290861936E-13 -6.786440484860922E-16 -2.393404232101987E-14 1.279538579968997E-16
q -5.824004753177597E-15 1.780297151845564E-14 1.196219787992417E-12 9.175681958017051E-15 1.890976918525101E-13 -2.783226456092966E-16
tp -1.059050290861936E-13 1.196219787992417E-12 1.101810569206496E-8 5.974576276551279E-12 1.791959238854204E-9 2.658849536286577E-13
node -6.786440484860922E-16 9.175681958017051E-15 5.974576276551279E-12 7.233081432039919E-8 -7.232377291323612E-8 6.292557213022947E-11
peri -2.393404232101987E-14 1.890976918525101E-13 1.791959238854204E-9 -7.232377291323612E-8 7.261994142211548E-8 -6.287717697028758E-11
i 1.279538579968997E-16 -2.783226456092966E-16 2.658849536286577E-13 6.292557213022947E-11 -6.287717697028758E-11 2.22085548482759E-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 14.26   n/a E2021B10  

21985 Šejna           Discovered 1999 Dec. 2 by L. Šarounová at Ondřejov.
Karel Šejna (1896-1982) was the conductor of the Czech Philharmonic Orchestra during 1938-1972 and cocreator of the era of Talich and Ančerl. He was a significiant interpreter of Mahler, Wagner and Bruckner, and his recordings of the compositions of Smetana, Dvořák, Fibich and Suk are superb.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20020427/MPCPages.arcLast Updated: 2003-10-02

[ show close-approach data ]
Alternate Designations
 1999 XG15 = 1996 FY16 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2021-Sep-23 04:14 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin