Helena

00101, 1868 PA, 1868PA, I68P00A

All data for this body: [vot]

MPC data
Name (number) Helena (101)
a 2.58356
e 0.14058
i / sin(i) 10.1919 / 0.17694
q 2.22036
Q 2.94676
ω 347.7835
Node 343.3645
m 276.1616
n 0.2373
Epoch 2460800.5
nobs 7096
nopp 64
Years observed 1871-2025
rms 0.50
Best values
[raw, vot]

Value Standard error
Parent
 
ap 2.583
ep 0.110
sin(ip) 0.180
G 0.150
H 8.390
Mass
D 61.64 0.564
pV 0.197 0.0059
Value
Rotational Period 23.000
Period quality 3
Spectral Class S
Spectral Class Score 40.000
Proper elements data
[raw, vot]

ap ep sin(ip) Author Reference Method
2.5833 0.1101 0.1800 Novakovic_Radovic_Todovic 2003A&A...403.1165K Numeric-Nov-2024
Diameter data
[raw, vot]

Value Uncertainty up Uncertainty down Author Reference Method
57.22 1.542 1.542 Ryan&Woodward 2010AJ....140..933R IRAS-STM
60.38 0.730 0.730 Usui 2011PASJ...63.1117U NEATM
61.22 6.120 6.120 Ali-Lagoa 2018A&A...612A..85A NEATM
65.84 1.300 1.300 Tedesco 2002AJ....123.1056T STM
66.89 6.690 6.690 Ali-Lagoa 2018A&A...612A..85A NEATM
67.22 2.950 2.950 Masiero 2012ApJ...759L...8M NEATM
72.39 3.267 3.267 Ryan&Woodward 2010AJ....140..933R IRAS-NEATM
Albedo data
[raw, vot]

Value Uncertainty up Uncertainty down Author Reference Method
0.157 0.0146 0.0146 Ryan&Woodward 2010AJ....140..933R IRAS-NEATM
0.182 0.0220 0.0220 Masiero 2012ApJ...759L...8M NEATM
0.190 0.0080 0.0080 Tedesco 2002AJ....123.1056T STM
0.207 0.0410 0.0410 Ali-Lagoa 2018A&A...612A..85A NEATM
0.247 0.0490 0.0490 Ali-Lagoa 2018A&A...612A..85A NEATM
0.252 0.0137 0.0137 Ryan&Woodward 2010AJ....140..933R IRAS-STM
G data
[raw, vot]

Value Uncertainty up Uncertainty down Author Reference Method
0.15 MPC-2023-12-94 MPC-2023-12-94 Phot
H data
[raw, vot]

Value Uncertainty up Uncertainty down Author Reference Method
8.39 MPC-2023-12-04 MPC-2023-12-04 Phot
Periods
[raw, vot]

Value Quality Side real or Synodic Author Reference Method
11.5 1 Synodic Behrend LCDB Lightcurve
11.546 2 Synodic Behrend LCDB Lightcurve
23.08 3 Synodic Harris 1989Icar...81..314H Lightcurve
23.16 2 Synodic Lagerkvist 1981A&AS...45..177L Lightcurve
Spectral Class Data
[raw, vot]

Class 1 Class 2 Probability of Class 1 Probability of Class 2 Taxonomy Wavelength Author Reference Method
S Bus-DeMeo VISNIR DeMeo 2009Icar..202..160D SPEC
S Bus VIS Bus 2002Icar..158..146B SPEC
S 1.000000 Mahlke VISNIR Mahlke 2022A&A...665A..26M SPEC
S 1.000000 Mahlke VISNIR Mahlke 2022A&A...665A..26M SPEC
Sp Howell VISNIR Howell 1994JGR....9910847H PHOT