J/AJ/168/190 Binary stars: visual orbits & interferometry (Tokovinin, 2024)
Orbits of binary stars: from visual measures to speckle interferometry.
Tokovinin A.
<Astron. J., 168, 190 (2024)>
=2024AJ....168..190T 2024AJ....168..190T
ADC_Keywords: Stars, double and multiple; Binaries, orbits; Interferometry;
Optical
Keywords: Binary stars ; Visual binary stars ; Speckle interferometry ;
Orbit determination
Abstract:
Knowledge of the orbits of visual binary stars has always been one of
the fundamentals of astronomy. Based historically on the visual
measures, nowadays the orbits rely more (or exclusively) on the
accurate speckle data. This prompts reconsideration of the methods of
orbit calculation, undertaken here and illustrated by 20 examples,
from accurate to drastically revised and tentative orbits. Good
understanding and critical assessment of the input data is a key
requirement, especially concerning visual measures. Combination of
visual and speckle data is still needed for long-period binaries, but
the relative weights must match their respective errors. When the
orbit can be fully constrained only by accurate speckle data, the old
measures should be ignored. Orbits can be classified into three
grades: (A) fully constrained, (B) semiconstrained, and (C)
preliminary or tentative. Typical use cases of visual orbits are
listed. Accurate parallaxes from Gaia, together with the orbits, will
greatly expand the data on stellar masses. Continued speckle
monitoring will be an essential complement to Gaia, but the vast
amount of new pairs will restrict future work on orbits to the most
interesting or relevant objects.
Description:
Observations of the 20 pairs of visual binaries were made over
decades, from the beginning of the 1900s to late 2024. References from
multiple sources are given in Table 1. The different methods used for
the positional measurements and residuals are given in Table 2 and
include adaptive optics, Gaia, visual micrometer measurement, and
speckle interferometry. See Section 4.
Here I use mostly speckle measures made at the 4.1m Southern
Astrophysical Research (SOAR) telescope using the HRCam instrument
(Tokovinin+ 2010, J/AJ/139/743); the latest papers
(Mason+ 2023, J/AJ/166/139; Tokovinin+ 2024, J/AJ/168/28) give
references to prior publications of the results.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 137 20 Visual orbits
table2.dat 58 488 Position measurements and residuals
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
J/AJ/106/352 : Speckle observations of binary stars VIII (Hartkopf+ 1993)
J/AJ/111/936 : ICCD Speckle obs. of binary stars. XIII (Hartkopf+ 1996)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)
J/AJ/144/56 : Speckle interferometry at SOAR in 2012 (Tokovinin+, 2012)
J/AJ/150/151 : DSSI obs of binaries. VI. Measures in 2014 (Horch+, 2015)
J/AJ/150/50 : Speckle interferometry at SOAR in 2014 (Tokovinin+, 2015)
J/MNRAS/455/4136 : Kepler triples (Borkovits+, 2016)
J/AJ/152/213 : Interferometry & sp.: sigma Orionis (Schaefer+, 2016)
J/MNRAS/456/2070 : Eccentricity distribution: wide binaries (Tokovinin+, 2016)
J/ApJ/844/103 : Orbit alignment in triple stars (Tokovinin, 2017)
J/MNRAS/473/4497 : Binary stars astrom. & phot. measurements (Roberts+, 2018)
J/ApJS/235/6 : Updated Multiple Star Cat. (MSC): Dec 2023 (Tokovinin, 2018)
J/ApJ/871/63 : How to constrain M dwarf. II. Nearby binaries (Mann+, 2019)
J/AJ/161/144 : Inner & outer orbits: 13 mult. stars syst. (Tokovinin, 2021)
J/MNRAS/517/2925 : ORB6 binaries in Gaia EDR3 (Chulkov+, 2022)
J/MNRAS/512/3383 : Wide binaries eccentricities with Gaia EDR3 (Hwang+, 2022)
J/AJ/163/161 : Spectro. of Subsyst.: Mult. Stars. VIII. (Tokovinin, 2022)
J/AJ/164/58 : Speckle Interferometry at SOAR in 2021 (Tokovinin+, 2022)
J/ApJ/941/8 : RV measurements of Castor Aa and Ba (Torres+, 2022)
J/AJ/163/178 : The Solar Neighborh. XLIV. M dwarfs: SOAR (Vrijmoet+, 2022)
J/A+A/674/A25 : Gaia DR3. spurious signals (Holl+, 2023)
J/AJ/166/139 : 2022 SOAR speckle interferometry:double stars (Mason+, 2023)
J/AJ/165/160 : Subsystems orbits in multiple stars. IX (Tokovinin, 2023)
J/AJ/168/28 : Speckle interferometry: SOAR 2023 (Tokovinin+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- WDS WDS code
12- 24 A13 --- ID Discoverer designation
26- 33 F8.3 yr Per [1.7/3200] Period, P
35- 39 F5.3 yr e_Per [0.01/2.8]? Uncertainty in Per
41- 48 F8.3 yr T [1913/2165] Time of periastron passage
50- 54 F5.3 yr e_T [0.04/0.75]? Uncertainty in T
56- 60 F5.3 --- e [0.17/0.97] Eccentricity
62- 66 F5.3 --- e_e [1e-3/1e-1]? Uncertainty in e
68 A1 --- f_e [*] *: fixed value in orbit fit
70- 75 F6.4 arcsec a [0.019/4.2] Semi-major axis
77- 82 F6.4 arcsec e_a [8e-4/2.8e-2]? Uncertainty in a
84- 89 F6.2 deg Omega [16/237] Position angle of ascending
node Ω
91- 96 F6.2 deg e_Omega [0.04/697]? Uncertainty in Ω
98- 103 F6.2 deg omega [8.6/326] Longitude of periastron from
ascending node ω
105- 110 F6.2 deg e_omega [0.35/675]? Uncertainty in ω
112- 117 F6.2 deg i [20/160] Orbital inclination
119- 123 F5.2 deg e_i [0.04/11]? Uncertainty in i
125 A1 --- f_i [*] *: fixed value in orbit fit
127 A1 --- Grade Orbit grade (1)
129- 137 A9 --- Ref Previous orbit (2)
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Note (1): Flag as follows:
A = fully constrained
B = semiconstrained
C = preliminary
Note (2): References to previous orbits as follows:
Doc1990d = Docobo & Costa (1990IAUDS.112....1D 1990IAUDS.112....1D)
Gomez2022 = Gomez et al. (2022MNRAS.509.4229G 2022MNRAS.509.4229G)
Izm2019 = Izmailov (2019AstL...45...30I 2019AstL...45...30I)
Msn2019 = Josties & Mason (2019IAUDS.199....1J 2019IAUDS.199....1J)
Msn2023 = Mason et al. (2023, J/AJ/166/139)
Tok2015c = Tokovinin et al. (2015, J/AJ/150/50)
Tok2022f = Tokovinin et al. (2022, J/AJ/164/58)
Zir2003 = Zirm (2003IAUDS.151....1Z 2003IAUDS.151....1Z)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- WDS WDS code
12- 20 F9.4 yr Date [1847/2024.4] Date; Julian year (T)
22- 27 F6.2 deg PA [0.0/360] Position angle (Θ)
29- 34 F6.4 arcsec Sep [2e-3/1.8] Separation (ρ)
36- 41 F6.4 arcsec e_Sep [2e-3/10] Uncertainty in Separation
(σ) (1)
43- 48 F6.1 deg (O-C)PA [-147/267] Residual in PA (O-CΘ)
50- 56 F7.4 arcsec (O-C)Sep [-0.25/0.3] Residual in Sep (O-Cρ)
58 A1 --- Meth Measurement method (2)
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Note (1): Errors of 9.9999 correspond to ignored measurements and
non-resolutions.
Note (2): Measurement techniques. Code as follows:
A = adaptive optics (1 occurrence)
G = Gaia (5 occurrences)
H = Hipparcos (8 occurrences)
M = visual micrometer measurement (197 occurrences)
S = speckle interferometry at SOAR (165 occurrences)
s = speckle interferometry at other telescopes (112 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 10-Jun-2025