J/A+A/380/238 Long-period companions of multiple stars (Shatsky, 2001)
The long-period companions of multiple stars tend to have
moderate eccentricities
Shatsky N.
<Astron. Astrophys. 380, 238 (2001)>
=2001A&A...380..238S 2001A&A...380..238S
ADC_Keywords: Stars, double and multiple
Keywords: binaries: visual - stars: statistics; formation
Description:
We examined the statistics of an angle gamma between the radius vector
of a visual companion of a multiple star and the vector of its
apparent relative motion in the system. We found that for the wide
physical subsystems of the 174 objects from the Multiple Star
Catalogue (MSC, Cat. J/A+AS/124/75) gamma is bell-shaped. Table 1
presents the separation and position angle of visual outer companions
of the sample multiples, and the relative motion (since discovery) and
its direction - angle gamma with its error. Positions are taken for
the first epoch mostly from Washington Double Star catalogue (WDS,
Cat. I/237) and from Hipparcos (Cat. I/239) or Tycho (Cat. I/239
and I/259) catalogues for the second epoch. Orbital motion in inner
subsystems of multiple stars is taken into account in gamma when
significant. Table 2 gives the cross-identification of objects and
components in different catalogues.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 174 Position parameters and angles gamma
table2.dat 90 174 Objects cross-identification
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See also:
I/237 : The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
I/211 : CCDM (Components of Double and Multiple stars) (Dommanget+ 1994)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
J/A+AS/124/75 : Multiple star catalogue (MSC) (Tokovinin 1997-1999)
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 Object ID in WDS (Cat. I/237) (G1)
12- 13 A2 --- Comp Components designations in MSC,
Cat. J/A+AS/124/75
15- 19 F5.1 arcsec Sep Separation from primary for second epoch
21- 23 I3 deg PA Position angle for second epoch
25- 27 I3 deg gamma [0-360[ gamma-angle for second epoch
29- 30 I2 deg e_gamma [2-30[ error of gamma
32- 35 F4.1 arcsec delta [0-15] motion - relative position change (2)
37- 39 A3 --- Note [cw*123moOxX]? Note (3)
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Note (2): Motion is equal to the difference of proper motion of companions
multiplied by epoch difference, i.e. it is a relative shift of the
secondary component during the history of observations.
Note (3): Note on origin of position parameters and details of gamma
calculation:
c = first epoch Sep,PA are taken from CCDM (Cat. I/211) rather than
from WDS (Cat. I/237)
w = second epoch position is taken from WDS (Cat. I/237)
(no HIP or Tycho id)
* = one of the alternative Hipparcos solutions is accepted
1,2,3 = Hipparcos or Tycho photocenter positions are computed for
primary, secondary or both subsystems of the object, respectively
m = Tycho-II proper motion difference is used to compute gamma
instead of Sep, PA-change.
O,o = position parameters are corrected for orbital motion in primary,
secondary subsystems of the object
X,x = uncertainty from unpredictable motion in primary, secondary
subsystem is taken into account in e_gamma
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- WDS Object ID in WDS (Cat. I/237) (G1)
12- 21 A10 --- IDS Object ID in Index Catalogue IDS
(1963IDS...C......0J 1963IDS...C......0J) (2)
23- 24 A2 --- Comp Components designations in MSC,
Cat. J/A+AS/124/75
26- 30 A5 --- m_WDS ? Components desig. in WDS (3)
32- 41 A10 --- CCDM ? Object ID in CCDM (Cat. I/211) (4)
43- 44 A2 --- m_CCDM ? Components designations in CCDM
46- 51 I6 --- HIP1 ? HIP (Cat. I/239) number of primary component
53- 58 I6 --- HIP2 ? HIP (Cat. I/239) number of secondary
(empty if HIP2=HIP1)
60- 61 A2 --- m_HIP1 ? Components designations in DMSA/C (5)
63- 74 A12 --- TYCHO1 ? Tycho identifier of primary
76- 87 A12 --- TYCHO2 ? Tycho identifier of secondary
89- 90 A2 --- r_TYCHO1 [ 12]? Tycho version (I/239) or I/259)
for TYCHO1 and TYCHO2 (6)
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Note (2): Index Double Star catalogue identification: also approximate
coordinates in the same form as for WDS (Cat. I/237)
but for equinox 1900.0
Note (3): Multiple visual systems are denoted as AB-C or AB-CD in WDS
(Cat. I/237) when position parameters are given there with
respect to corresponding (visual) photocenters of subsystems
Note (4): CCDM (Cat. I/211) identification (when available) differs
sometimes from WDS (Cat. I/237) due to round-off errors in
produced object identifier
Note (5): Component identifiers as given in Component Solutions of the Double
and Multiple Star Annex of Hipparcos Catalogue (Cat. I/239) in case
of a single HIP-number for both components in question
Note (6): Position code of a reference of TYCHO1 and TYCHO2 fields:
first symbol gives a reference for primary component,
second symbol for secondary.
1 = Tycho Catalogue (1997, Cat. I/239)
2 = Tycho-2 Catalogue (2000, Cat. I/259)
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Global notes:
Note (G1): Identification of the multiple star in WDS (Cat. I/237)
represents approximate equatorial coordinates of object for equinox
2000.0 in format: [HHMMMsDDMM], where HH is RAh, MMM is RAm with
decimal minutes, s is a declination sign, DD is DEd, MM is DEm.
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Acknowledgements: N. Shatsky
(End) N. Shatsky [Sternberg Institute] 05-Oct-2001