18154+5720 HDS 2577 (HD 168242)
18h 15m 21.73s +57° 20' 08.3" P.A. 330.00 sep 0.2 mag 8.93,9.56 Sp K0 dist. 64.35 pc (209.91 l.y.)
| Coord 2000 |
18154+5720 |
|
Discov num |
HDS2577 |
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Comp |
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Coord arcsec 2000 |
18 15 21.73 +57 20 08.3 |
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| Date first |
1991 |
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Date last |
2016 |
|
Obs |
15 |
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| Pa first |
139 |
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Pa last |
330.4 |
|
P.A. Now (θ) |
330.4° |
|
| Sep first |
0.2 |
|
Sep last |
0.186 |
|
Sep. Now (ρ) |
0.186" |
|
| Mag pri |
8.93 |
|
Mag sec |
9.56 |
|
delta mag (ΔM) |
0.63 |
|
Spectral class |
K0 (yellow-orange) |
|
| Pri motion ra |
+018 |
|
Sec motion ra |
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| Pri motion dec |
-065 |
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Sec motion dec |
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| Notes |
O
(Orbital solution) |
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This double is physical.
OTHER CATALOGS AND DESIGNATIONS
| Name |
HD 168242 |
|
Constellation |
Draco |
|
SAO |
30845 |
|
HIP |
89455 |
|
| Tycho2 |
3912-01259-1 |
|
Gaia DR2 |
2151781024774974592 |
|
HD |
168242 |
|
BD |
BD+57 1856 |
|
| Distance |
64.35 |
|
Distance ly |
209.91 |
|
ORBITAL ELEMENTS
| Period (P) | 82y | ± 65 |
Periastron (T) | 1997.8y | ± 6.6 |
Semi-major axis (a) | 0.4a | ± 0.21 |
| Eccentricity (e) | 0.36 | ± 0.36 |
Inclination (i) | 62° | ± 14 |
Longitude of periastron (ω) | 313° | ± 51 |
| Node (Ω) | 259° | ± 19 |
Notes | | |
Reference | RAO2015 | |
| Equinox | 2000 | |
Last observation | 2013 | |
Grade | 4 | (1=Definitive, 9=Indet.) |
| label |
theta |
rho |
| 2000 |
246.5 |
0.242 |
| 2001 |
251.4 |
0.258 |
| 2002 |
255.8 |
0.272 |
| 2003 |
259.8 |
0.281 |
| 2004 |
263.6 |
0.287 |
| 2005 |
267.3 |
0.291 |
| 2006 |
270.9 |
0.291 |
| 2007 |
274.6 |
0.289 |
| 2008 |
278.3 |
0.284 |
| 2009 |
282.2 |
0.279 |
| 2010 |
286.3 |
0.272 |
| 2011 |
290.6 |
0.264 |
| 2012 |
295.1 |
0.256 |
| 2013 |
300.0 |
0.248 |
| 2014 |
305.1 |
0.240 |
| 2015 |
310.6 |
0.233 |
| 2016 |
316.5 |
0.227 |
| 2017 |
322.6 |
0.222 |
| 2018 |
328.9 |
0.219 |
| 2019 |
335.3 |
0.218 |
| 2020 |
341.8 |
0.219 |
| 2021 |
348.1 |
0.221 |
| 2022 |
354.3 |
0.226 |
| 2023 |
0.2 |
0.232 |
| 2024 |
5.7 |
0.240 |
| 2025 |
10.9 |
0.249 |
| 2026 |
15.7 |
0.259 |
| 2027 |
20.1 |
0.270 |
| 2028 |
24.1 |
0.282 |
| 2029 |
27.8 |
0.294 |
| 2030 |
31.2 |
0.307 |
|
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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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