J/AJ/154/200 The nearby white dwarf/red dwarf pair 40 Eri BC (Mason+, 2017)
Binary star orbits.
V. The nearby white dwarf/red dwarf pair 40 Eri BC.
Mason B.D., Hartkopf W.I., Miles K.N.
<Astron. J., 154, 200 (2017)>
=2017AJ....154..200M 2017AJ....154..200M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, double and multiple ; Binaries, orbits
Keywords: binaries: general - binaries: visual - stars: individual (40 Eri BC) -
techniques: interferometric
Abstract:
A new relative orbit solution with new dynamical masses is determined
for the nearby white dwarf-red dwarf pair 40 Eri BC. The period is
230.29±0.68 years. It is predicted to close slowly over the next
half-century, getting as close as 1.32" in early 2066. We determine masses
of 0.573±0.018 M☉ for the white dwarf and 0.2036±0.0064 M☉
for the red dwarf companion. The inconsistency of the masses determined
by gravitational redshift and dynamical techniques, due to a premature
orbit calculation, no longer exists.
Description:
The pair is suitable for observation by the USNO speckle camera on the
26" refractor in Washington (Mason et al. 2011, J/AJ/141/157; 2011,
J/AJ/142/46); at the suggestion of Howard Bond, the pair was
repeatedly observed until it was too far off the meridian at twilight.
Observed three times per night on six different nights, the calibration
and methodology are as described in B. D. Mason & W. I. Hartkopf
(2017AJ....154..183M 2017AJ....154..183M).
Measures used in the orbit solution (Section 3), from the Washington Double
Star Catalog (Mason et al. 2001, Cat. B/wds) are presented in Table 3.
Objects:
-------------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------------
04 15 21.73 -07 39 17.4 40 Eri BC = * omi02 Eri C
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 96 175 Catalog Measurements of 40 Eri BC
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
J/AJ/123/1023 : Binary star orbits (Seymour+, 2002)
J/A+A/486/843 : White dwarf-red dwarf binaries in the SDSS (Augusteijn+, 2008)
J/AJ/141/157 : Speckle interferometry at USNO. XVI. (Mason+, 2011)
J/AJ/142/46 : Speckle interferometry at USNO. XVII. (Mason+, 2011)
J/AJ/153/20 : Speckle interferometry at USNO. XXI. (Mason+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 yr Epoch [1851.06/2016.129] Mean Julian epoch of
observation (1)
11- 16 F6.2 deg theta [0.34/359.6] Position angle θ (2)
18- 22 F5.3 arcsec rho [1.3/9.71] Angular separation ρ
24- 25 I2 --- n [1/14] Number of nights in the mean position
27- 30 F4.1 deg (O-C)t [-8.8/6.1] The θ (O-C) residual
32- 37 F6.3 arcsec (O-C)r [-1.787/1.198] The ρ (O-C) residual
39- 42 F4.1 --- Weight [0/52.4] Observation weight
44- 70 A27 --- Ref Observation reference
72- 90 A19 --- BibCode BibCode, when available
92- 96 A5 --- Notes Additional notes (3)
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Note (1): The measures listed have been converted to Julian epoch (JE), using
the IAU approved conversion: JY=(BYx0.999978641)+0.041439661.
Note (2): The position angles are for the equinox of the epoch of observation.
Note (3): Note as follows:
A = Measure given zero weight in final orbit solution due to excessive
residuals;
B = Measure by J. Gledhill cited by Lewis (1906MmRAS..56....1L 1906MmRAS..56....1L);
C = Measure uncertain or estimated by observer;
D = Number of nights varies 50% or more between angle and separation measures.
In this case, N=Nθ/Nρ, rounding down;
E = Original data published at the Besselian Epoch converted to the Julian
Epoch as described in the text;
F = Identification error in publication corrected;
G = Mean of multiple measures on the same photographic plate;
H = Quadrant flipped 180° from published value;
I = Measure given reduced weight in final orbit solution due to large
residuals.
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History:
From electronic version of the journal
References:
Hartkopf et al. Paper I. 1999AJ....117.1023M 1999AJ....117.1023M
Seymour et al. Paper II. 2002AJ....123.1023S 2002AJ....123.1023S, Cat. J/AJ/123/1023
Mason et al. Paper III. 2010AJ....140..242M 2010AJ....140..242M
Mason et al. Paper IV. 2010AJ....140..735M 2010AJ....140..735M
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 17-Jul-2018