J/ApJ/926/1 Gaia EDR3 triple stellar systems within 100pc (Tokovinin, 2022)
Resolved Gaia Triples.
Tokovinin A.
<Astrophys. J., 926, 1 (2022)>
=2022ApJ...926....1T 2022ApJ...926....1T
ADC_Keywords: Stars, double and multiple; Parallaxes, trigonometric; Surveys;
Optical
Keywords: Binary stars ; Visual binary stars ; Multiple stars
Abstract:
A sample of 392 low-mass hierarchical triple stellar systems within
100pc resolved by Gaia as distinct sources is defined. Owing to the
uniform selection, the sample is ideally suited to study unbiased
statistics of wide triples. The median projected separations in their
inner and outer pairs are 151 and 2569 au, respectively, and the
median separation ratio is close to 15. Some triples appear in
nonhierarchical configurations, and many are just above the dynamical
stability limit. Internal motions in these systems are known with
sufficient accuracy to determine the orbital motion sense of the outer
and inner pairs and to reconstruct the eccentricity distributions. The
mean inner and outer eccentricities are 0.66±0.02 and 0.54±0.02,
respectively; the less eccentric outer orbits are explained by
dynamical stability. The motion sense of the inner and outer pairs is
almost uncorrelated, implying a mean mutual inclination of
83.1°±4.5°. The median mass of the most massive component is
0.71M☉, and the median system mass is 1.53M☉. In a 0.69
fraction of the sample the primary belongs to the inner binary, while
in the remaining systems it is the tertiary. A 0.21 fraction of the
inner subsystems are twins with mass ratios >0.95. The median outer
mass ratio is 0.41; it decreases mildly with increasing outer
separation. Presumably, these wide hierarchies were formed by collapse
and fragmentation of isolated cores in low-density environments and
represent a small fraction of initial systems that avoided dynamical
decay. Wide pre-main-sequence multiples in Taurus could be their
progenitors.
Description:
I searched the full Gaia Catalog of Nearby Stars (GCNS) within 100pc
(Gaia Col. 2021, J/A+A/649/A6) of 331312 stars to identify groups of
three or more stars that are located close in space and share a common
proper motion. See Section 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 89 1176 Data on resolved wide triple systems
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2020)
J/A+A/380/238 : Long-period companions of multiple stars (Shatsky, 2001)
J/A+A/384/1030 : Orientation of orbits in triple stars (Sterzik+, 2002)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/147/86 : From binaries to multiples. I. FG-67 sample (Tokovinin, 2014)
J/MNRAS/456/2070 : Eccentricity distribution of wide bin. (Tokovinin+, 2016)
J/A+A/599/A14 : Taurus ultra-wide pairs (Joncour+, 2017)
J/ApJ/844/103 : Orbit alignment in triple stars (Tokovinin, 2017)
J/ApJS/235/6 : Updated Multiple Star Cat. (MSC): Sept 2021 (Tokovinin, 2018)
J/AJ/157/216 : Stellar mult. rate of M dwarfs within 25pc (Winters+, 2019)
J/A+A/649/A6 : Gaia Catalog of Nearby Stars - GCNS (Gaia collaboration, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- N [1/392] Sequential system number (1)
5- 14 A10 --- ID WDS code (HHMMm+DDMM; J2000 for the
brightest star)
16- 20 F5.2 mas Plx [9.6/87] Gaia parallax
22 A1 --- m_ID Component label (2)
24- 42 I19 --- Gaia Gaia EDR3 identifier
44- 48 F5.2 mag Gmag [4.86/20.75] Gaia G-band magnitude
50- 53 F4.2 Sun Mass [0.07/1.5] Mass
55- 60 F6.2 arcsec Sep [0.5/328]? Angular separation, ρ (3)
62- 66 F5.1 deg PA ? Position angle, θ
68- 72 F5.1 deg gamma ? Gamma angle
74- 78 F5.1 deg e_gamma [0.1/119.3]? Error in Gamma
80- 84 F5.2 mas/yr delmu [0.1/74.1]? Relative PM, Δµ
86- 89 F4.2 --- mup [0.04/1.41]? Normalized speed, µ'
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Note (1): Three lines per system in order:
inner primary, inner secondary, tertiary
Note (2): Labels A, B, C in order of increasing mass
Note (3): Angular separation and then following columns are empty for
the primary, then correspond to the inner and outer subsystems.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Sep-2023