02318+8916 WRH 39 Aa,Ab
02h 31m 49.09s +89° 15' 50.7" P.A. 175.00 sep 0.1 mag 2.30,4.30 Sp F7:Ib-IIv dist. 132.63 pc (432.64 l.y.)
| Coord 2000 |
02318+8916 |
|
Discov num |
WRH 39 |
|
Comp |
Aa,Ab |
|
Coord arcsec 2000 |
02 31 49.09 +89 15 50.7 |
|
| Date first |
1937 |
|
Date last |
2014 |
|
Obs |
8 |
|
| Pa first |
250 |
|
Pa last |
175 |
|
P.A. Now (θ) |
175° |
|
| Sep first |
0.2 |
|
Sep last |
0.085 |
|
Sep. Now (ρ) |
0.085" |
|
| Mag pri |
2.30 |
|
Mag sec |
4.30 |
|
delta mag (ΔM) |
2 |
|
Spectral class |
F7:Ib-IIv (yellow-white) |
|
| Pri motion ra |
+038 |
|
Sec motion ra |
|
|
| Pri motion dec |
-015 |
|
Sec motion dec |
|
|
| Notes |
N
O
(See Notes, Orbital solution) |
|
This double is physical.
02318+8916 SYSTEM COMPONENTS
| Show |
name |
SAO |
coord |
wds_name |
last |
obs |
pa |
sep |
mag1 |
mag2 |
d_mag |
orb |
current |
| Show |
|
308 |
02 31 49 +89 15 51 |
WRH 39 Aa,Ab |
2014 |
8 |
175 |
0.1 |
2.30 |
4.30 |
2.00 |
Y |
<=== |
| Show |
Polaris |
308 |
02 31 49 +89 15 51 |
STF 93 AB |
2016 |
65 |
236 |
18.4 |
2.04 |
9.10 |
7.06 |
|
|
| Show |
|
308 |
02 31 49 +89 15 51 |
STF 93 AC |
2016 |
7 |
103 |
39.0 |
2.04 |
13.80 |
11.76 |
|
|
| Show |
|
308 |
02 31 49 +89 15 51 |
STF 93 AD |
2016 |
8 |
194 |
83.2 |
2.04 |
14.30 |
12.26 |
|
|
| Show |
|
|
02 30 43 +89 15 39 |
STF 93 BC |
2015 |
4 |
83 |
53.1 |
9.10 |
13.80 |
4.70 |
|
|
| Show |
|
|
02 30 43 +89 15 39 |
STF 93 BD |
2014 |
3 |
179 |
69.4 |
9.10 |
14.30 |
5.20 |
|
|
Quintuple system
4 estimated visually detectable stars in this system
OTHER CATALOGS AND DESIGNATIONS
| Common name |
Polaris |
|
Constellation |
Ursa Minor |
|
SAO |
308 |
|
HIP |
11767 |
|
| Tycho2 |
4628-00237-1 |
|
Gaia DR2 |
576402619921505664 |
|
HD |
8890 |
|
HR |
424 |
|
| GC |
2243 |
|
ADS |
1477 |
|
BD |
BD+88 8 |
|
Bayer |
Alpha Ursae Minoris |
|
| Bayer name |
Alp UMi |
|
Flamsteed |
1 Ursae Minoris |
|
Flamsteed name |
1 UMi |
|
FK5 |
907 |
|
| Distance |
132.63 |
|
Distance ly |
432.64 |
|
Bayer greek |
α UMi |
|
| Other names |
Lodestar, Cynosura, Alruccabah, Phoenice, Polare, Stella Polare, Tramontana, Angel Stern, Navigatoria, Star of Arcady, Yilduz, Mismar, Polyarnaya |
|
ORBITAL ELEMENTS
| Period (P) | 29.59y | ± 0.02 |
Periastron (T) | 1987.66y | ± 0.13 |
Semi-major axis (a) | 0.1204a | ± 0.0059 |
| Eccentricity (e) | 0.608 | ± 0.005 |
Inclination (i) | 146.2° | ± 10.9 |
Longitude of periastron (ω) | 303.01° | ± 0.75 |
| Node (Ω) | 191.4° | ± 4.9 |
Notes | n | |
Reference | Evs2018 | |
| Equinox | 2000 | |
Last observation | 2014 | |
Grade | 4 | (1=Definitive, 9=Indet.) |
| label |
theta |
rho |
| 2000 |
73.5 |
0.163 |
| 2001 |
69.3 |
0.167 |
| 2002 |
65.2 |
0.170 |
| 2003 |
61.2 |
0.172 |
| 2004 |
57.3 |
0.173 |
| 2005 |
53.4 |
0.173 |
| 2006 |
49.5 |
0.171 |
| 2007 |
45.5 |
0.169 |
| 2008 |
41.3 |
0.165 |
| 2009 |
36.9 |
0.159 |
| 2010 |
32.1 |
0.151 |
| 2011 |
26.7 |
0.142 |
| 2012 |
20.4 |
0.130 |
| 2013 |
12.7 |
0.116 |
| 2014 |
2.6 |
0.098 |
| 2015 |
347.3 |
0.077 |
| 2016 |
319.1 |
0.054 |
| 2017 |
260.7 |
0.041 |
| 2018 |
202.5 |
0.052 |
| 2019 |
170.0 |
0.068 |
| 2020 |
149.2 |
0.082 |
| 2021 |
134.0 |
0.094 |
| 2022 |
122.2 |
0.105 |
| 2023 |
112.6 |
0.115 |
| 2024 |
104.5 |
0.125 |
| 2025 |
97.5 |
0.134 |
| 2026 |
91.4 |
0.142 |
| 2027 |
85.9 |
0.149 |
| 2028 |
80.8 |
0.155 |
| 2029 |
76.2 |
0.161 |
| 2030 |
71.8 |
0.165 |
|
|
Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
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Measures: green=micrometric, blue=interferometric, purple=photographic |
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