J/ApJ/745/24 A search for new companions with CHARA (Raghavan+, 2012)
A search for separated fringe packet binaries using the CHARA Array.
Raghavan D., Farrington C.D., ten Brummelaar T.A., McAlister H.A.,
Ridgway S.T., Sturmann L., Sturmann J., Turner N.H.
<Astrophys. J., 745, 24 (2012)>
=2012ApJ...745...24R 2012ApJ...745...24R
ADC_Keywords: Interferometry ; Stars, double and multiple ; Stars, nearby ;
Stars, G-type
Keywords: binaries: visual - solar neighborhood - stars: solar-type - surveys -
techniques: interferometric
Abstract:
We present the results of a comprehensive search for new companions to
nearby solar-type stars using the separated fringe packet (SFP)
technique at the Center for High Angular Resolution Astronomy (CHARA)
Array. Our search included 636 observations of 186 stars, searching
for companions with separations of approximately 8-80 mas and moderate
brightness ratios (ΔK≲1.5). This survey was undertaken to
support a comprehensive assessment of companions to solar-type stars
within 25 pc. We detected separated fringe companions to two stars
(HD 3196 and 79096) and found faint companion signatures to two more
stars (HD 98231 and 137763). All of these companions are previously
known by spectroscopic methods, and three of them have speckle
interferometric observations as well. The faint companion seen to
HD 98231 represents the first visual detection of this spectroscopic
companion. Our null detection for new companions implies that the
presumed gap between spectroscopic and visual techniques has largely
been filled for nearby solar-type stars, thanks to systematic
radial-velocity observations over multiple decades and a thorough
coverage using visual techniques, especially speckle interferometric
observations. We also generate simulated fringe packets to derive
detection limits for SFP binaries using the CHARA Array.
Description:
We obtained 636 observations on 186 stars (targeted from Raghavan et
al. 2010, Cat. J/ApJS/190/1 and Farrington 2008PhDT........11F 2008PhDT........11F)
between 2007 January and 2008 July over approximately 100 nights. All
of our observations were made using two-telescope baselines and the
CHARA Classic IR pupil-plane beam combiner through the K' filter. Five
of the 186 stars were observed only once, and the remaining 181 were
observed 2-15 times. The vast majority of our observations were made
using the S1-E1 (45%) and S1-W1 (35%) baselines, which not only are
among the longest baselines of the Array with telescope separations of
331m and 279m, respectively, but also are roughly orthogonal.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 6 186 List of the 186 stars observed (table added by CDS)
table1.dat 40 636 Separated Fringe Packet Observations
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See also:
VI/46 : Second Catalog of Interferometric Measurements of Binary Stars
J/ApJ/736/89 : Search for companions around nearby stars (Janson+, 2011)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)
J/ApJS/181/62 : Survey of young solar analogs (Metchev+, 2009)
J/AJ/135/1334 : Speckle interferometry at the USNO station (Hartkopf+, 2008)
J/AJ/136/312 : 2001-2006 WIYN binary stars speckle observations (Horch+, 2008)
J/AJ/121/3224 : Speckle interferometry of HIP binaries (Mason+, 2001)
J/A+A/323/139 : K magnitude of Pleiades low-mass binaries (Bouvier+ 1997)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD [166/224465] HD number
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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- 6 I6 --- HD HD number
8- 17 F10.4 d MJD [54125.2/54674.5] Modified Julian Date of
mid-exposure observation
19- 23 A5 --- Base The two-telescope baseline configuration
25- 27 I3 Hz Freq [65/150] Fringe frequency
29- 31 I3 --- Ng [65/358] Number of good fringe scans
33- 36 I4 --- Ntot [137/1016] Number of total fringe scans
38- 40 A3 --- SFP? [Yes/ ] Detection of Separated Fringe Packet?
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Jul-2013