J/AJ/144/7 Near-IR imaging of Hipparcos astrometric binaries (Tokovinin+, 2012)
Revealing companions to nearby stars with astrometric acceleration.
Tokovinin A., Hartung M., Hayward T.L., Makarov V.V.
<Astron. J., 144, 7 (2012)>
=2012AJ....144....7T 2012AJ....144....7T
ADC_Keywords: Photometry, infrared ; Interferometry ; Binaries, spectroscopic ;
Proper motions ; Stars, masses ; Radial velocities
Keywords: binaries: general
Abstract:
A subset of 51 Hipparcos astrometric binaries among FG dwarfs within
67pc has been surveyed with the Near-Infrared Coronagraphic Imager
adaptive optics system at Gemini-S, directly resolving for the first
time 17 subarcsecond companions and 7 wider ones. Using these data
together with published speckle interferometry of 57 stars, we compare
the statistics of resolved astrometric companions with those of a
simulated binary population. The fraction of resolved companions is
slightly lower than expected from binary statistics. About 10% of
astrometric companions could be "dark" (white dwarfs and close pairs
of late M-dwarfs). To our surprise, several binaries are found with
companions too wide to explain the acceleration. Re-analysis of
selected intermediate astrometric data shows that some acceleration
solutions in the original Hipparcos catalog are spurious.
Description:
The observations of 51 Hipparcos astrometric binaries were taken in
queue mode in the period from 2011 September 15 to November 8 with the
Near-Infrared Coronagraphic Imager (NICI; an 85-element curvature
adaptive optic (AO) instrument based on natural guide stars) on the
Gemini South telescope. To avoid saturation, we selected narrowband
filters with central wavelengths of 2.272µm and 1.587µm for the
red and blue imaging channels.
Results of speckle interferometry were obtained with the 4m telescopes
Blanco and SOAR between 2008 and 2011 and published in Tokovinin et
al. (2010, Cat. J/AJ/139/743) and Hartkopf et al. (2012, Cat.
J/AJ/143/42). These papers contain data on 57 astrometric binaries
from the FG-67pc sample, 9 of which were also observed with
Near-Infrared Coronagraphic Imager (NICI). Most observations were done
in the I or Stromgren γ bands.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 57 24 Measures of companions resolved with Near-Infrared
Coronagraphic Imager (NICI)
table2.dat 73 99 Summary data on observed astrometric binaries
table4.dat 57 11 Selected distant Hipparcos stars with large
accelerations and significant differences
between Tycho-2 and Hipparcos proper motions
notes.dat 379 44 Notes
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2013)
V/130 : Geneva-Copenhagen Survey of Solar neighbourhood III (Holmberg+, 2009)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/AJ/143/42 : Speckle interferometry with SOAR in 2010-11 (Hartkopf+, 2012)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)
J/ApJS/162/207 : Radial velocities of solar-type stars (Abt+, 2006)
J/AJ/129/2420 : Proper motion derivatives of binaries (Makarov+, 2005)
J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)
J/AJ/106/773 : Mass-luminosity relation (Henry+, 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP HIP identifier
8- 16 F9.4 yr Date Observation date
18- 22 F5.1 deg PA(2.2) Relative position angle (1)
24- 29 F6.3 arcsec Sep(2.2) Relative separation (1)
31- 34 F4.2 mag Dmag(2.2) Relative photometry Δm (1)
36- 40 F5.1 deg PA(1.6) Relative position angle (2)
42- 47 F6.3 arcsec Sep(1.6) Relative separation (2)
49- 52 F4.2 mag Dmag(1.6) Relative photometry Δm (2)
54 A1 --- Rem Remarks (? = uncertain measure)
56- 57 A2 --- Comp Component (AB or AC)
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Note (1): Of resolved pairs measured on the red images (narrowband filter with
central wavelength of 2.272µm).
Note (2): Of resolved pairs measured on the blue images (narrowband filter with
central wavelength of 1.587µm).
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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- 6 I6 --- HIP HIP identifier
8- 9 I2 mas plx Rounded value of Hipparcos (Cat. I/239) parallax
11- 12 I2 mas/yr dpm Difference in proper motion
14- 15 I2 mas/yr2 ddpm Acceleration (1)
17- 20 F4.1 km/s DRV ? Radial velocity amplitude (if the RV
variability is found in Nordstroem et al.,
2004, Cat. V/117, superseded by Cat. V/130)
22- 23 A2 --- n_DRV Variability (-, C or SB) (2)
25- 28 F4.2 Msun Mass Stellar mass (see Section 3 for more details)
30- 33 F4.2 --- q ? The mass ratio M2/M1 of resolved pairs
(see Section 3 for more details)
35- 39 F5.3 arcsec Sep ? Separation
41- 46 F6.1 yr Per ? Order-of-magnitude estimates of orbital
periods from the third Kepler law (3)
48 A1 --- Obs1 Results of observation with the Near-Infrared
Coronagraphic Imager (NICI) (n=unresolved,
N=resolved, or -=not observed)
50 A1 --- Obs2 Results of speckle observation (s=unresolved,
S=resolved, or -=not observed)
52 A1 --- Obs3 W=listed as resolved binary in the WDS (B/wds)
54- 71 A18 --- Rem Remarks (4)
73 A1 --- Note [*] Notes (in notes.dat file)
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Note (1): Zero indicates non-detection of astrometric perturbations in
Makarov & Kaplan (2005, Cat. J/AJ/129/2420).
Note (2): Flag on DRV as follows:
- = no radial velocity data;
C = constant radial velocity;
SB = known spectroscopic orbit.
Note (3): Per=[ρ3*pHIP-3*M1(1+q)]1/2, assuming that the separation
equals the semimajor axis.
Note (4): Indicate spectroscopic and astrometric binaries with known orbits
(in these cases the true period is listed instead of Per) or
binary-star designations of known pairs in the WDS (Cat. B/wds)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP HIP identifier
8- 11 F4.1 mas plx Hipparcos (Cat. I/239) parallax
13- 18 F6.1 mas/yr pmRA1 Proper motion in right ascension from
HIP (Cat. I/239)
20- 24 F5.1 mas/yr pmDE1 Proper motion in declination from
HIP (Cat. I/239)
26- 30 F5.1 mas/yr pmRAt2 Proper motion in right ascension from
Tycho-2 (Cat. I/259)
32- 36 F5.1 mas/yr pmDEt2 Proper motion in declination from
Tycho-2 (Cat. I/259)
38- 42 F5.1 mas/yr pmRA2 Proper motion in right ascension from
HIP2 (Cat. I/311)
44- 48 F5.1 mas/yr pmDE2 Proper motion in declination from
HIP2 (Cat. I/311)
50- 53 F4.1 mas/yr2 ddpm Acceleration
55- 57 F3.1 --- Sig Formal significance of the acceleration
(see Section 5 for more details)
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP HIP identifier
8-379 A372 --- Note Notes
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 01-Aug-2013