J/MNRAS/422/2765 Orbital motion monitoring of A-star multiples (De Rosa+ 2012)
The Volume-limited A-Star (VAST) Survey.
II. Orbital motion monitoring of A-type star multiples
De Rosa R.J., Patience J., Vigan A., Wilson P.A., Schneider A.,
McConnell N.J., Wiktorowicz S., Marois C., Song I., Macintosh B.,
Graham J.R., Bessell M.S., Doyon R., Lai O.
<Mon. Not. R. Astron. Soc., 422, 2765 (2012)>
=2012MNRAS.422.2765D 2012MNRAS.422.2765D
ADC_Keywords: Binaries, orbits ; Stars, A-type
Keywords: binaries: general - binaries: close: techniques: high angular
resolution
Abstract:
As a part of our ongoing Volume-limited A-Star (VAST) adaptive optics
survey, we have obtained observations of 26 binary systems with
projected separations <100AU, 13 of which have sufficient historical
measurements to allow for refinement of their orbital elements. For
each system with an estimated orbit, the dynamical system mass
obtained was compared with the system mass estimated from
mass-magnitude relations. Discrepancies between the dynamical and
theoretical system mass can be explained by the presence of a
previously unresolved spectroscopic component, or by a non-solar
metallicity of the system. Using this approach to infer the presence
of additional companions, a lower limit to the fraction of binaries,
triples, and quadruples can be estimated as 39%, 46%, and 15%, for
systems with at least one companion within 100AU. The fraction of
multiple systems with three or more components shows a relative
increase compared to the fraction for Solar-type primaries resolved in
previous volume-limited surveys. The observations have also revealed a
pair of potentially young (<100Myr) M-dwarf companions, which would
make an ideal benchmark for the theoretical models during the pre-Main
Sequence contraction phase for M-dwarfs. In addition to those systems
with orbit fits, we report 13 systems for which further orbital
monitoring observations, are required, 11 of which are newly resolved
as a part of the VAST survey.
Description:
File "measures.dat" contains each separation and position angle
measurement used within the paper to fit the orbital parameters of
each system. The corresponding uncertainties on each value are also
presented, alongside the epoch of observation, and the reference from
which the historical observation was obtained.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 90 26 Basic properties of sample members
table6.dat 113 28 Derived parameters of individual components
table8.dat 156 12 Estimated orbital parameters
measures.dat 70 355 List of binary separation and position angle
measurements
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- S [OM] Sample: Orbit or Monitoring
3- 8 I6 --- HIP Hipparcos (Cat. I/311) number
10- 22 A13 --- Name Other name of the star
24- 32 A9 --- HR Harvard Revised (Cat. V/50) number of star
34- 39 I6 --- HD Henry Draper (Cat. III/135) number of star
41- 45 I5 --- ADS ? Aitken Double Star number
47- 55 A9 --- SpT MK Spectral type
57- 61 F5.2 pc Dist Heliocentric distance of star
63- 66 F4.2 pc e_Dist Mean error on Dist
68- 72 F5.3 mag VTmag Hipparcos/Tycho blue magnitude
74- 78 F5.3 mag e_VTmag Mean error on VTmag
80- 83 F4.2 mag Ksmag 2MASS Ks-band magnitude
85- 88 F4.2 mag e_Ksmag Mean error on Ksmag
90 A1 --- r_Ksmag [ab] Ks magnitude from other source (1)
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Note (1): Reference as follows:
a = Ducati, Cat. II/237
b = Morel & Magnenat, 1978, Cat. II/7
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1 A1 --- n_HIP [+*] Note about this system (1)
3- 8 I6 --- HIP Hipparcos (Cat. I/311)
10- 11 A2 --- m_HIP Multiplicity component
13- 17 F5.2 mag VTmag Tycho VT magnitude
19- 22 F4.2 mag e_VTmag Mean error on VTmag
24- 28 F5.2 mag Kmag Estimated 2MASS Ks magnitude
30- 33 F4.2 mag e_Kmag Mean error on Kmag
35- 39 F5.2 mag V-K V-K color index
41- 44 F4.2 mag e_V-K Mean error on V-K
46- 50 F5.2 mag VMAG Absolute V magnitude
52- 55 F4.2 mag e_VMAG Mean error on VMAG
57- 60 F4.2 mag KMAG Absolute K magnitude
62- 65 F4.2 mag e_KMAG Mean error on KMAG
67- 74 A8 --- Comp Components
76- 78 A3 --- SB Spectroscopic binary feature (SB1 or SB2)
80-113 A34 --- Ref Reference
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Note (1): Notes as follows:
+ = The spectroscopic binary reported by Abt (1965ApJS...11..429A 1965ApJS...11..429A) is
the system resolved within the AO data.
* = The individual component magnitudes may be significantly biased
due to the presence of additional companions within the resolution
limit of the Tycho2 and 2MASS observations.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- HIP Hipparcos number
7- 9 I3 --- Nm Number of measures
11- 17 F7.3 yr Per Period
19- 23 F5.3 yr e_Per Mean error of Per (upper)
25- 29 F5.3 yr E_Per Mean error of Per (lower)
32- 37 F6.4 arcsec a Semi-major axis
39- 44 F6.4 arcsec e_a Mean error on a (upper)
46- 51 F6.4 arcsec E_a Mean error on a (lower)
53- 58 F6.2 deg i Inclination of the orbit
60- 63 F4.2 deg e_i Mean error on i (upper)
65- 68 F4.2 deg E_i Mean error on i (lower)
71- 76 F6.2 deg Ome Longitude of node Ω
78- 81 F4.2 deg e_Ome Mean error on Ome (upper)
83- 86 F4.2 deg E_Ome Mean error on Ome (lower)
89- 96 F8.3 yr T0 Epoch of periastron
98-102 F5.3 yr e_T0 Mean error on T0 (upper)
104-108 F5.3 yr E_T0 Mean error on T0 (lower)
111-115 F5.3 --- e Orbit eccentricity
117-121 F5.3 --- e_e Mean error on e (upper)
123-127 F5.3 --- E_e Mean error on e (lower)
130-135 F6.2 deg ome Longitude of periastron ω
137-140 F4.2 deg e_ome Mean error on ome (upper)
142-145 F4.2 deg E_ome Mean error on ome (lower)
148-151 F4.2 Msun Mass System mass
153-156 F4.2 Msun e_Mass Mean error on Mass
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Byte-by-byte Description of file: measures.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- HIP Hipparcos number
7- 16 F10.2 d JD Observation epoch (Julian date)
18- 24 F7.2 d Date Observation epoch (Decimal year)
26- 30 F5.3 arcsec rho Measured binary separation ρ
32- 36 F5.3 arcsec e_rho Uncertainty on rho
38- 44 F7.3 deg theta Measured binary position angle θ
46- 50 F5.3 deg e_theta Uncertainty on theta
52- 70 A19 --- Ref Bibcode of bibliographic source of measurement
(blank when no bibliographic code is known)
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Acknowledgements: R.J. De Rosa, rjderosa(at)asu.edu
References:
de Rosa et al., Paper I 2011MNRAS.415..854D 2011MNRAS.415..854D
(End) R.J. De Rosa [ASU, USA] 02-Nov-2012