15396+7959 STF 1989 (Pi2 UMi)
15h 39m 38.61s +79° 58' 59.6" P.A. 23.00 sep 0.7 mag 7.32,8.15 Sp F2V dist. 120.05 pc (391.6 l.y.)
| Coord 2000 |
15396+7959 |
|
Discov num |
STF1989 |
|
Comp |
|
|
Coord arcsec 2000 |
15 39 38.61 +79 58 59.6 |
|
| Date first |
1832 |
|
Date last |
2013 |
|
Obs |
124 |
|
| Pa first |
24 |
|
Pa last |
22.8 |
|
P.A. Now (θ) |
20.4° |
|
| Sep first |
0.7 |
|
Sep last |
0.67 |
|
Sep. Now (ρ) |
0.591" |
|
| Mag pri |
7.32 |
|
Mag sec |
8.15 |
|
delta mag (ΔM) |
0.83 |
|
Spectral class |
F2V (yellow-white) |
|
| Pri motion ra |
-033 |
|
Sec motion ra |
-033 |
|
| Pri motion dec |
+039 |
|
Sec motion dec |
+039 |
|
| Notes |
N
O
(See Notes, Orbital solution) |
|
This double is physical.
OTHER CATALOGS AND DESIGNATIONS
| Name |
Pi2 UMi |
|
Constellation |
Ursa Minor |
|
SAO |
2588 |
|
HIP |
76695 |
|
| Tycho2 |
4563-01084-1 |
|
Gaia DR2 |
1708946939955140352 |
|
HD |
141652 |
|
GC |
21163 |
|
| ADS |
9769 |
|
BD |
BD+80 487 |
|
Bayer |
Pi 2 Ursae Minoris |
|
Bayer name |
Pi2 UMi |
|
| Flamsteed |
18 Ursae Minoris |
|
Flamsteed name |
18 UMi |
|
Distance |
120.05 |
|
Distance ly |
391.6 |
|
| Bayer greek |
π2 UMi |
|
ORBITAL ELEMENTS
| Period (P) | 171.62y | ± 8.68 |
Periastron (T) | 1904.15y | ± 2.89 |
Semi-major axis (a) | 0.464a | ± 0.083 |
| Eccentricity (e) | 0.961 | ± 0.014 |
Inclination (i) | 135.2° | ± 10.5 |
Longitude of periastron (ω) | 274° | ± 22.4 |
| Node (Ω) | 123.4° | ± 32.6 |
Notes | n | |
Reference | Hrt2008 | |
| Equinox | 2000 | |
Last observation | 2004 | |
Grade | 3 | (1=Definitive, 9=Indet.) |
| label |
theta |
rho |
| 2000 |
25.6 |
0.643 |
| 2001 |
25.4 |
0.642 |
| 2002 |
25.2 |
0.641 |
| 2003 |
25.0 |
0.640 |
| 2004 |
24.8 |
0.638 |
| 2005 |
24.6 |
0.637 |
| 2006 |
24.3 |
0.635 |
| 2007 |
24.1 |
0.634 |
| 2008 |
23.9 |
0.632 |
| 2009 |
23.7 |
0.630 |
| 2010 |
23.5 |
0.628 |
| 2011 |
23.2 |
0.626 |
| 2012 |
23.0 |
0.624 |
| 2013 |
22.8 |
0.621 |
| 2014 |
22.5 |
0.619 |
| 2015 |
22.3 |
0.616 |
| 2016 |
22.1 |
0.613 |
| 2017 |
21.8 |
0.611 |
| 2018 |
21.6 |
0.608 |
| 2019 |
21.4 |
0.605 |
| 2020 |
21.1 |
0.601 |
| 2021 |
20.9 |
0.598 |
| 2022 |
20.6 |
0.595 |
| 2023 |
20.4 |
0.591 |
| 2024 |
20.1 |
0.587 |
| 2025 |
19.8 |
0.583 |
| 2026 |
19.6 |
0.579 |
| 2027 |
19.3 |
0.575 |
| 2028 |
19.1 |
0.571 |
| 2029 |
18.8 |
0.567 |
| 2030 |
18.5 |
0.562 |
|
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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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