J/A+A/509/A52 Search for companions with VLT/NACO (Chauvin+, 2010)
Deep imaging survey of young, nearby austral stars.
VLT/NACO near-infrared Lyot-coronographic observations.
Chauvin G., Lagrange A.-M., Bonavita M., Zuckerman B., Dumas C.,
Bessell M.S., Beuzit J.-L., Bonnefoy M., Desidera S., Farihi J.,
Lowrance P., Mouillet D., Song I.
<Astron. Astrophys. 509, A52 (2010)>
=2010A&A...509A..52C 2010A&A...509A..52C
ADC_Keywords: Stars, nearby ; Stars, faint ; Photometry, infrared
Keywords: instrumentation: adaptive optics -
instrumentation: high angular resolution - methods: observational -
methods: statistical - brown dwarfs - planetary systems
Abstract:
Since November 2002, we have conducted the largest deep imaging survey
of the young, nearby associations of the southern hemisphere. Our goal
is detection and characterization of substellar companions at
intermediate (10-500AU) physical separations. We have observed a
sample of 88 stars, mostly G to M dwarfs, that we essentially identify
as younger than 100Myr and closer to Earth than 100pc. The VLT/NACO
adaptive optics instrument of the ESO Paranal Observatory was used to
explore the faint circumstellar environment between typically 0.1 and
10". We report the discovery of 17 new close (0.1-5.0") multiple
systems. HIP 108195AB and C (F1III-M6), HIP 84642AB (a∼14AU, K0-M5)
and TWA 22AB (a∼1.8AU; M6-M6) confirmed comoving systems. TWA 22AB is
likely to be a astrometric calibrator that can be used to test
evolutionary predictions. Among our complete sample, a total of 65
targets observed with deep coronagraphic imaging. About 240 faint
candidates were detected around 36 stars. Follow-up observations VLT
or HST for 83% of these stars enabled us to identify a fraction of
contaminants. The latest results about the substellar companions to
GSC 08047-00232, AB Pic and 2M1207, confirmed during this survey and
published earlier, are reviewed. Finally, the statistical analysis of
our complete set of coronagraphic limits enables us to place
constraints on the physical and properties of giant planets between
typically 20 and 150AU.
Description:
Identification and relative position and photometry of all faint
sources detected during the VLT/NACO survey.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table23.dat 121 88 Sample of southern young, nearby stars observed
during our VLT/NACO deep imaging survey
(tables 2 and 3 of the paper)
table8.dat 91 370 Relative position and photometry measurements
for 40 stars with companion candidates detected
with NaCo at VLT
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Byte-by-byte Description of file: table23.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Star Name
18- 19 I2 h RAh Hour of Right Ascension (J2000.0)
21- 22 I2 min RAm Minute of Right Ascension (J2000.0)
24- 28 F5.2 s RAs Second of Right Ascension (J2000.0)
30 A1 --- DE- Sign of the Declination (J2000.0)
31- 32 I2 deg DEd Degree of Declination (J2000.0)
34- 35 I2 arcmin DEm Arcminute of Declination (J2000.0)
37- 38 I2 arcsec DEs Arcsecond of Declination (J2000.0)
40- 42 I3 deg GLAT Galactic longitude
44- 46 A3 --- SpT MK spectral type
48- 52 F5.1 pc Dist Heliocentric distance
54- 55 A2 --- l_Age [≥] Limit flag on Age
56- 58 I3 Myr Age Estimated age
60- 63 F4.1 mag Vmag ? V magnitude
65- 70 F6.3 mag Kmag ? K magnitude
72- 77 A6 --- Mode Mode (CI = coronagraphy) and filter (H or Ks)
78 A1 --- n_Mode [*] *: S13 camera used in that case
80 A1 --- Mult Multiplicity: B=binary, T=triple, Q=quadruple
82- 99 A18 --- BinInfo Binarity informations (F1/F2/F3) (3)
101-103 A3 --- Note [CCs ] CC(s) indicates presence of companion
candidates
105-121 A17 --- Target Target name for objects studied in table8
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Note (3): Information about binarity is made of 3 slash-separated flags:
* First flag:
N = new multiple system;
K = known/cataloged multiple system
* Second flag:
VIS = identified visual binary system;
HIP = Hipparcos astrometric binary system;
SB = spectroscopic binary system
* Third flag:
Ph = confirmed physical system;
Co = comoving system;
nothing if only an optical binary
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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- 17 A17 --- Target Target name
19- 24 A6 --- OName Other names
26- 30 A5 --- Cand Candidate number (cc-NN)
32- 41 A10 "DD/MM/YYYY" Obs.Date Observing UT date
43- 44 A2 --- Filt [Ks H] Filter
46- 51 F6.3 arcsec Sep Relative separation
53- 57 F5.3 arcsec e_Sep rms uncertainty on Sep
59- 64 F6.2 deg PA Relative position angle
66- 69 F4.2 deg e_PA rms uncertainty on PA
71- 74 F4.1 mag Dmag ? Relative magnitude in Filter
76- 78 F3.1 mag e_Dmag ? rms uncertainty on Dmag
80- 81 A2 --- Status [UC PB] Identification status (1)
83- 91 A9 --- Note Notes (2)
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Note (1): Identification status as follows:
U = undefined, observed at only one epoch
B = stationary background contaminants
C = confirmed comoving companions
PB = probably background
Note (2): Note to detail the companion nature or when VLT data are combined
with those from other telescopes (HST, USNO, 2MASS).
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Acknowledgements:
Gael Chauvin, gael.chauvin(at)obs.ujf-grenoble.fr
(End) Patricia Vannier [CDS] 10-Aug-2009