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
IMPORTANT: The SSD Announcement email list is now available. Major changes are coming in the near future, including possible hostname and/or URL changes. To be notified of such changes, subscribe to this email list.

Please visit this page for more details.

JPL Small-Body Database Browser
Search: [ help ]  
321 Florentina
Classification: Main-belt Asteroid          SPK-ID: 2000321
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ hide orbit diagram ]

For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.

[ revert to old Java-based viewer ]

Orbital Elements at Epoch 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 34 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04666053706193093 3.5652e-08  
a 2.885377376068378 1.1403e-08 au
q 2.750744118074682 1.047e-07 au
i 2.587287565963579 4.3842e-06 deg
node 40.22458690232654 9.522e-05 deg
peri 36.24914656531664 0.00010818 deg
M 323.2149041460748 5.11e-05 deg
tp 2458783.424447291555
0.00025422 TDB
period 1790.203328175723
n .2010944758810453 1.1921e-09 deg/d
Q 3.020010634062073 1.1935e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2725  
   data-arc span      46234 days (126.58 yr)  
   first obs. used      1893-01-16  
   last obs. used      2019-08-18  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .44849  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Sep-23 19:07:32  

Additional Information
 Earth MOID = 1.76614 au 
 Jupiter MOID = 2.09894 au 
 T_jup = 3.290 
[ 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 10.1   n/a MPO365244  
diameter diameter 27.974 km 0.103 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
rotation period rot_per 2.871 h n/a LCDB (Rev. 2019-January); Warner et al., 2009 Published Reference List:
[Van Houten-Groeneveld, I.; van Houten, C.J. (1958) Astrophys. J. 127, 253-273.]
[Slivan, S.M.; Binzel, R.P. (1996) Icarus 124, 452-470.]
[Behrend, R. (1999) Observatoire de Geneve web site,]
[Frey, G. (2000) Minor Planet Bull. 27, 29-30; Proc. 2000 IAPPP Phot. and CCD Imaging Symp., 1-12.]
[Slivan, S.M.; Binzel, R.P.; Crespo da Silva, L.D.; Kaasalainen, M.; et al. (2003) Icarus 162, 285-307.]
[Warner, B.D. (2006) Minor Planet Bull. 33, 39-41.]
[Fauvaud, S.; Fauvuad, M.; Richard, F. (2011) Minor Planet Bull. 38, 134-135.]
geometric albedo albedo 0.425   0.037 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
B-V BV 0.792   0.036 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=1.44, mean=5.02, max.=10.60) deg.
U-B UB 0.410   0.044 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=1.44, mean=5.02, max.=10.60) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices
SMASSII spectral type spec_B S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

321 Florentina          Discovered 1891-Oct-15 by Palisa, J. at Vienna
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1959 RS 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
FirstGov 2019-Oct-21 21:17 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin