J/A+A/670/A102 WDS systems with rho>1000 arcsec (Gonzalez-Payo+, 2023)
Reaching the boundary between stellar kinematic groups and very wide binaries.
IV. The widest Washington Double Star systems with rho≥1000 arcsec in Gaia DR3.
Gonzalez-Payo J., Caballero J.A., Cortes-Contreras M.
<Astron. Astrophys. 670, A102 (2023)>
=2023A&A...670A.102G 2023A&A...670A.102G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Photometry ; Optical ;
Stars, distances ; Stars, masses
Keywords: surveys - virtual observatory tools - astrometry -
binaries: general - binaries: visual
Abstract:
With the latest Gaia DR3 data, we analyse the widest pairs in the
Washington Double Star (WDS) catalogue with angular separations,
ρ, greater than 1000 arcsec.
We confirmed the pairs' membership to stellar systems based on
common proper motions, parallaxes, and (when available) radial
velocities, together with the locii of the individual components in
colour-magnitude diagrams. We also looked for additional closer
companions to the ultrawide pairs, either reported by WDS or found by
us with a new Gaia astrometric search. In addition, we determined
masses for each star (and white dwarf) and, with the projected
physical separation, computed the gravitational potential energy,
|Ug*|, of the systems.
Of the 155 159 pairs currently catalogued by WDS, there are 504 with
ρ>1000-arcsec. Of these, only 2 ultrawide pairs have not been
identified, 10 do not have any available astrometry, 339 have not
passed a conservative filtering in proper motion or parallax, 59 are
members of young stellar kinematic groups, associations or open
clusters, and only 94 remain as bona fide ultrawide pairs in the
galactic field. Accounting for the additional members at shorter
separations identified in a complementary astrometric and
bibliographic search, we found 79 new stars (39 reported, plus 40 not
reported by WDS) in 94 ultrawide stellar systems. This sample is
expanded when including new close binary candidates with large Gaia
DR3 RUWE, sigmaVr, or a proper motion anomaly. Furthermore, the
large fraction of subsystems and the non-hierarchical configurations
of many wide systems with three or more stars is remarkable. In
particular, we found 14 quadruple, 2 quintuple, 3 sextuple, and 2
septuple systems. The minimum computed binding energies,
|Ug*|∼1033J, are in line with theoretical predictions of tidal
destruction by the Galactic gravitational potential. The most fragile
and massive systems have huge projected physical separations of well
over 1pc. Therefore, they are either in the process of disruption or
they are part of unidentified juvenile stellar kinematic groups.
Description:
We built our sample from the latest version of the WDS. For each of
the 155 159 resolved pairs, WDS tabulates the WDS identifier (based on
J2000 position), discoverer code and number, number of observations
and of components (when there are more than two), date, position angle
(θ, i.e. orientation on the celestial plane of the companion
with respect to the primary), and ρ of the first and last
observations, magnitudes, and proper motions of the two components,
along with the equatorial coordinates of the primary of the pair and
notes about the pair.
As a result, there were 266 stars in 243 resolved Gaia sources and
in 94 systems that passed to the next step of our analysis. All the
systems and resolved Gaia sources are listed in Tables B.2 and B.3.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 225 330 Stars in young stellar kinematic groups
tableb2.dat 291 242 Basic data of the 94 galactic field systems
tableb3.dat 234 242 Masses, rho, theta, separations and gravitational
binding energy of the systems identified in the
sample of work
tableb4.dat 142 145 Candidate stars to be part of the gam Cas
association, in order of the distance to the
central star gam Cas
--------------------------------------------------------------------------------
See also:
J/A+A/583/A85 : Binaries in beta Pic moving group (Alonso-Floriano+, 2015)
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 28 A28 --- Name Name of the star as registered in Simbad
30- 74 A45 --- Disc Discoverer codes in WDS catalogue (1)
76- 77 I2 h RAh Right ascension (J2000)
79- 80 I2 min RAm Right ascension (J2000)
82- 86 F5.2 s RAs Right ascension (J2000)
88 A1 --- DE- Declination sign (J2000)
89- 90 I2 deg DEd Declination (J2000)
92- 93 I2 arcmin DEm Declination (J2000)
95- 98 F4.1 arcsec DEs Declination (J2000)
100-103 F4.1 mag Gmag ? G-band mean magnitude from Gaia DR3
(Blank if not available in Gaia DR3)
105-121 A17 --- Group Group where the star is located (2)
123-225 A103 --- r_Group Reference(s) for Group
--------------------------------------------------------------------------------
Note (1): Registers marked with blanks are new young star candidates
Note (2): Groups as follows:
32 Ori = 32 Orionis
AB Dor = AB Doradus
Ale13 = Alessi 13
bet Pic = bet Pictoris
Car = Carina
Car-Near = Carina-Near
Car-Vela = Carina-Vela
gam Ca s = gam Cassiopeia
Castor = Castor (alf Geminorum)
CBer = Coma Berenice
chi01 For = chi01 Fornacis
Col = Columba
eps Cha = eps Chamaelontis
G-X = [TPY2019] Group-X
Hya = Hyades
IC2391 = IC2391 Supercluster
LCC = Lower Centarus Crux
SCO = Scorpio-Centaurus
Tuc-Hor = Tucana-Horologium
UCL = Upper Centaurus-Lupus
UMa = Ursa Major
VCA = Volans-Carina
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- WDS WDS name (HHMMm+DDMM)
12- 26 A15 --- Disc WDS Discoverer code (formed by the current and
the first star of the system)
28- 36 A9 --- Mult Multiplicity order of the system
38- 46 A9 --- Type (Double, triple)
48- 75 A28 --- Star Name of the star as registered in Simbad
77- 78 I2 h RAh Right ascension (J2000)
80- 81 I2 min RAm Right ascension (J2000)
83- 87 F5.2 s RAs Right ascension (J2000)
89 A1 --- DE- Declination sign (J2000)
90- 91 I2 deg DEd Declination (J2000)
93- 94 I2 arcmin DEm Declination (J2000)
96- 99 F4.1 arcsec DEs Declination (J2000)
101 A1 --- l_Dist [~] Limit flag on Dist
102-107 F6.2 pc Dist Distance
109-113 F5.3 pc e_Dist ? Distance error
116-119 F4.1 mag Gmag ? G-band mean magnitude from Gaia DR3 (1)
121-123 A3 --- RUWE>10 [Yes/No ] The star has a RUWE parameter
bigger than 10
125-127 A3 --- pmanom [Yes/No ] The star has a pm anomaly (2)
129-131 A3 --- LsigmaVr [Yes/No ] The star has a large sigma_Vr
for its G magnitude
133-291 A159 --- Rem Remarks about the star
--------------------------------------------------------------------------------
Note (1): The maximum error in G provided by Gaia DR3 is less than 0.005 mag
Note (2): Kervella et al. (2019A&A...623A..72K 2019A&A...623A..72K); Brandt (2021ApJS..254...42B 2021ApJS..254...42B)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- WDS WDS name (HHMMm+DDMM)
15- 29 A15 --- Disc WDS Discoverer code (formed by the current
and the first star of the system)
31- 39 A9 --- Id Number of star inside the system
(ordered by decreasing bright in G)
41- 49 A9 --- Mult Multiplicity order of the system
51- 78 A28 --- Star Name of the star as registered in Simbad
80- 83 F4.2 Msun Mass Mass of the star
85- 89 F5.3 Msun e_Mass Mass error of the star
91- 97 F7.1 arcsec rho ? Physical projected separation between the
current and the first star of the system
99-103 F5.1 deg theta ? Position angle respect of the first star
of the system
105-114 F10.5 1000AU Sep ? Separation in 1000au between the current
and the first star of the system
116-123 F8.5 1000AU e_Sep ? Separation error in 1000au between the
current and the first star of the system
125-129 F5.2 10+33J E ?=- Gravitational binding energy of the whole
system ("---" if not available)
130-135 F6.3 10+33J e_E ? Gravitational binding energy error of the
whole system
137-234 A98 --- Rem Some remarks of the data
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 27 A27 --- Star Name of the star as registered in Simbad
29- 30 I2 h RAh Right ascension (J2000)
32- 33 I2 min RAm Right ascension (J2000)
35- 39 F5.2 s RAs Right ascension (J2000)
41 A1 --- DE- Declination sign (J2000)
42- 43 I2 deg DEd Declination (J2000)
45- 46 I2 arcmin DEm Declination (J2000)
48- 51 F4.1 arcsec DEs Declination (J2000)
53- 58 A6 --- SpType Spectral type according to Simbad
60 A1 --- l_Mass [~] Limit flag on Mass
61- 65 F5.2 Msun Mass ? Mass of the star
67- 70 F4.2 Msun e_Mass ? Mass error of the star
72- 75 F4.1 mag Gmag ? G-band mean magnitude from Gaia DR3
77- 80 F4.1 mag Jmag J-band mean magnitude from 2MASS
82- 86 F5.3 deg Dist Projected physical separation from gam Cas
88-142 A55 --- Rem Some remarks about the star
--------------------------------------------------------------------------------
Acknowledgements:
Javier Gonzalez-Payo, fcojgonz(at)ucm.es
References:
Caballero, Paper I 2009A&A...507..251C 2009A&A...507..251C
Caballero, Paper II 2010A&A...514A..98C 2010A&A...514A..98C
Alonso-Floriano et al., Paper III 2015A&A...583A..85A 2015A&A...583A..85A, Cat. J/A+A/583/A85
(End) Patricia Vannier [CDS] 26-Dec-2022