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 |
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Discov num |
THB 1 |
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Comp |
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Coord arcsec 2000 |
04 27 02.79 +25 42 22.6 |
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Date first |
1986 |
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Date last |
2016 |
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Obs |
57 |
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Pa first |
350 |
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Pa last |
182.6 |
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P.A. Now (θ) |
111.8° |
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Sep first |
0.1 |
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Sep last |
0.086 |
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Sep. Now (ρ) |
0.062" |
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Mag pri |
12.62 |
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Mag sec |
13.51 |
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delta mag (ΔM) |
0.89 |
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Spectral class |
M2.0+M2.5 (red/red) |
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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 |
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Constellation |
Taurus |
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HIP |
20777 |
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Tycho2 |
1820-00176-1 |
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Gaia DR2 |
151179966897747840 |
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HD |
283654 |
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Distance |
45.89 |
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Distance ly |
149.69 |
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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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