04271+2542 THB 1 (DF Tau)
04h 27m 02.79s +25° 42' 22.6" P.A. 183.00 sep 0.1 mag 12.62,13.51 Sp M2.0+M2.5 dist. 45.89 pc (149.69 l.y.)
| Coord 2000 |
04271+2542 |
|
Discov num |
THB 1 |
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Comp |
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Coord arcsec 2000 |
04 27 02.79 +25 42 22.6 |
|
| Date first |
1986 |
|
Date last |
2016 |
|
Obs |
57 |
|
| Pa first |
350 |
|
Pa last |
182.6 |
|
P.A. Now (θ) |
111.8° |
|
| Sep first |
0.1 |
|
Sep last |
0.086 |
|
Sep. Now (ρ) |
0.062" |
|
| Mag pri |
12.62 |
|
Mag sec |
13.51 |
|
delta mag (ΔM) |
0.89 |
|
Spectral class |
M2.0+M2.5 (red/red) |
|
| Pri motion ra |
+006 |
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Sec motion ra |
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| Pri motion dec |
-020 |
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Sec motion dec |
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| Notes |
N
O
(See Notes, Orbital solution) |
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This double is physical.
OTHER CATALOGS AND DESIGNATIONS
| Var name |
DF Tau |
|
Constellation |
Taurus |
|
HIP |
20777 |
|
Tycho2 |
1820-00176-1 |
|
| Gaia DR2 |
151179966897747840 |
|
HD |
283654 |
|
Distance |
45.89 |
|
Distance ly |
149.69 |
|
ORBITAL ELEMENTS
| Period (P) | 46.1y | ± 1.9 |
Periastron (T) | 1979.2y | ± 1.5 |
Semi-major axis (a) | 94.9m | ± 2.2 |
| Eccentricity (e) | 0.233 | ± 0.038 |
Inclination (i) | 145.5° | ± 1.6 |
Longitude of periastron (ω) | 309.2° | ± 3.5 |
| Node (Ω) | 33.9° | ± 5 |
Notes | n | |
Reference | Pra2017 | |
| Equinox | 2000 | |
Last observation | 2016 | |
Grade | 3 | (1=Definitive, 9=Indet.) |
| label |
theta |
rho |
| 2000 |
271.2 |
0.101 |
| 2001 |
265.7 |
0.103 |
| 2002 |
260.5 |
0.105 |
| 2003 |
255.4 |
0.106 |
| 2004 |
250.5 |
0.108 |
| 2005 |
245.7 |
0.109 |
| 2006 |
241.0 |
0.110 |
| 2007 |
236.4 |
0.110 |
| 2008 |
231.7 |
0.110 |
| 2009 |
227.1 |
0.110 |
| 2010 |
222.3 |
0.108 |
| 2011 |
217.5 |
0.107 |
| 2012 |
212.4 |
0.105 |
| 2013 |
207.1 |
0.102 |
| 2014 |
201.5 |
0.098 |
| 2015 |
195.4 |
0.094 |
| 2016 |
188.7 |
0.090 |
| 2017 |
181.3 |
0.085 |
| 2018 |
172.9 |
0.079 |
| 2019 |
163.4 |
0.074 |
| 2020 |
152.4 |
0.070 |
| 2021 |
140.1 |
0.066 |
| 2022 |
126.4 |
0.063 |
| 2023 |
111.8 |
0.062 |
| 2024 |
97.2 |
0.063 |
| 2025 |
83.2 |
0.065 |
| 2026 |
70.3 |
0.068 |
| 2027 |
58.5 |
0.071 |
| 2028 |
47.8 |
0.074 |
| 2029 |
38.0 |
0.077 |
| 2030 |
28.8 |
0.079 |
|
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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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