J/AJ/155/160 Multiple systems:relative positions and residuals (Tokovinin, 2018)
Dancing twins: stellar hierarchies that formed sequentially?
Tokovinin A.
<Astron. J., 155, 160 (2018)>
=2018AJ....155..160T 2018AJ....155..160T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, masses ; Spectral types ;
Parallaxes, trigonometric
Keywords: binaries: general - binaries: visual
Abstract:
This paper draws attention to the class of resolved triple stars with
moderate ratios of inner and outer periods (possibly in a mean motion
resonance) and nearly circular, mutually aligned orbits. Moreover,
stars in the inner pair are twins with almost identical masses, while
the mass sum of the inner pair is comparable to the mass of the outer
component. Such systems could be formed either sequentially (inside-out)
by disk fragmentation with subsequent accretion and migration, or by
a cascade hierarchical fragmentation of a rotating cloud. Orbits of
the outer and inner subsystems are computed or updated in four such
hierarchies: LHS 1070 (GJ 2005, periods 77.6 and 17.25 years), HIP 9497
(80 and 14.4 years), HIP 25240 (1200 and 47.0 years), and HIP 78842
(131 and 10.5 years).
Description:
The objects for this study were selected among triple systems with one
(or both) orbits already listed in the Sixth orbit catalog (Hartkopf et al.
2001AJ....122.3472H 2001AJ....122.3472H). The available astrometry was extracted from the WDS
database by B. Mason (Cat. B/wds) and complemented by recent speckle
measurements at the Southern Astrophysical Research (SOAR) 4.1 m telescope,
some of those still unpublished. One of the triples (HIP 9497) was
discovered at SOAR in 2008, another (HIP 78842) was discovered the same
year and with the same speckle instrument at the Blanco telescope
(Tokovinin et al. 2010, J/AJ/139/743).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 150 4 Overview of multiple systems
table3.dat 61 290 Relative positions and residuals
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/A+AS/121/71 : Orbits of 7 spectroscopic binaries in multiples
(Tokovnin, 1997)
J/PAZh/26/301 : Dynamical stability of triple stars (Orlov+, 2000)
J/A+A/384/1030 : Orientation of orbits in triple stars (Sterzik+, 2002)
J/MNRAS/389/925 : Triple and quadruple stars (Tokovinin, 2008)
J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)
J/A+A/545/A85 : LHS1070 photometry and spectroscopy (Rajpurohit+, 2012)
J/AJ/151/153 : Speckle interferometry at SOAR in 2015 (Tokovinin+, 2016)
J/ApJ/838/54 : Accurate astrometry & RVs of 4 multiple systems
(Tokovinin+, 2017)
J/ApJ/844/103 : Orbit alignment in triple stars (Tokovinin, 2017)
J/ApJS/235/6 : Updated Multiple Star Catalog (MSC) - May 2018
(Tokovinin, 2018)
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 designation (HHMMm+DDMM, J2000)
12- 13 I2 h RAh Simbad Hour of Right Ascension (J2000)
15- 16 I2 min RAm Simbad Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Simbad Second of Right Ascension (J2000)
24 A1 --- DE- Simbad Sign of the Declination (J2000)
25- 26 I2 deg DEd Simbad Degree of Declination (J2000)
28- 29 I2 arcmin DEm Simbad Arcminute of Declination (J2000)
31- 34 F4.1 arcsec DEs Simbad Arcsecond of Declination (J2000)
36- 40 I5 --- HIP ? Hipparcos number (NNNNN)
42- 46 F5.2 mag Vmag Combined visual magnitude
48- 58 A11 --- Name(O) Outer pair discoverer name (Cat. B/wds)
60- 65 F6.1 yr Per(O) Orbital period of the outer pair
67- 71 F5.3 arcsec a(O) Semimajor axis of the outer pair
73- 76 F4.2 Msun M1(O) Mass of the primary component of the outer pair
77 A1 --- n_M1(O) [s] Note on M1(O) (s=Mass sum)
79- 82 F4.2 Msun M2(O) Mass of the secondary component of the outer
pair
83 A1 --- n_M2(O) [s] Note on M2(O) (s=Mass sum)
85- 86 I2 deg Phi1 First value of mutual inclination Φ
88- 90 I3 deg Phi2 Second value of mutual inclination Φ
92- 97 F6.2 mas Plx Trigonometric parallax
99-101 A3 --- SpType MK spectral type from Simbad
103-114 A12 --- Name(I) Inner pair discoverer name (Cat. B/wds)
116-120 F5.2 yr Per(I) Orbital period of the inner pair
122-126 F5.3 arcsec a(I) Semimajor axis of the inner pair
128-132 F5.3 Msun M1(I) Mass of the primary component of the inner pair
134-138 F5.3 Msun M2(I) Mass of the secondary component of the inner
pair
140 A1 --- l_PO/PI [~] Limit flag on PO/PI
141-145 F5.2 --- PO/PI Ratio of outer and inner periods Per(O)/Per(I)
147-150 F4.2 --- e_PO/PI ? Uncertainty in PO/PI
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- WDS WDS designation (HHMMm+DDMM, J2000)
12- 16 A5 --- m_WDS Subsystem designation (1)
18- 26 F9.4 yr Date [1863.21/2017.9338] Date of observation
28- 32 F5.1 deg PA [0.4/359.0] Position angle
34- 39 F6.4 arcsec Sep [0.083/3.3117] Separation
41- 46 F6.4 arcsec e_Sep [0.002/2.15] Assumed error on Sep
48- 51 F4.1 deg (O-C)PA [-8.1/11.3] Residual in PA
53- 59 F7.4 arcsec (O-C)Sep [-0.2715/0.3096] Residual in Sep
61 A1 --- Ref Reference (2)
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Note (1): This column specifies the nature of the measurement: Ba,Bb refers to
the resolved inner pair, A,Ba to the resolved outer pair, and A,B to the
unresolved measure of the outer pair.
Note (2): Reference as follows:
G = Gaia (Cat. I/337);
H = Hipparcos (Cat. I/239);
K = Kohler et al. (2012A&A...541A..29K 2012A&A...541A..29K);
M = Micrometer measures;
P = Photographic;
S = Speckle interferometry at SOAR;
s = Other speckle interferometry.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 15-Nov-2018