J/A+A/419/167 BVRI photometry in metal-poor binaries (Zapatero Osorio+, 2004)
A CCD imaging search for wide metal-poor binaries.
Zapatero Osorio M.R., Martin E.L.
<Astron. Astrophys. 419, 167 (2004)>
=2004A&A...419..167Z 2004A&A...419..167Z
ADC_Keywords: Stars, double and multiple ; Photometry, UBVRI
Keywords: stars: subdwarfs - binaries: visual - stars: late-type -
stars: statistics
Abstract:
We explored the regions within a radius of 25 arcsec around
473 nearby, low-metallicity G- to M-type stars using (VR)I
optical filters and small-aperture telescopes. About 10% of
the sample was searched up to angular separations of 90
arcsec. We applied photometric and astrometric techniques to
detect true physical companions to the targets. The great
majority of the sample stars was drawn from the Carney-Latham
surveys; their metallicities range from roughly solar to
[Fe/H]=-3.5dex. Our I-band photometric survey detected
objects that are between 0 and 5mag fainter (completeness)
than the target stars; the maximum dynamical range of our
exploration is 9mag.
Description:
Observing dates, differential photometry and astrometry (rho
and position angle) of companion candidates around 473 nearby,
low-metallicity G- to M-type stars are provided in the
Table. The target stars were mainly taken from the
Carney-Latham surveys. Also provided are exposure times, the
FWHM of the CCD images, and the telescope used for collecting
the observations. The last column contains a flag indicating
whether the candidate is a confirmed physical companion.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 1391 Photometric and astrometric observations
notes.dat 80 55 Individual notes
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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- 10 A10 --- Name Name of the target star
11 A1 --- n_Name [*] note detailed in "notes.dat"" file
13- 18 F6.3 mag Vmag ? V magnitude of the target star
21 A1 --- Filter Filter (BVRI)
24- 34 A11 --- Tel Telescope
35- 38 I4 s ExpTime ? Exposure time
42- 45 F4.1 arcsec FWHM ? FWHM
53- 62 A10 "DD/MM/YYYY" Obsdate Observing date (1)
64 A1 --- l_rho Limit flag on rho
65- 70 F6.2 arcsec rho ? Angular separation of companion
71- 72 A2 --- u_rho [ :] Uncertainty flag on rho
76- 81 F6.2 deg PA ? Position angle of companion (2)
82- 83 A2 --- u_PA [ :] Uncertainty flag on PA
85 A1 --- l_Dmag Limit flag on Dmag
86- 90 F5.2 mag Dmag ? Differential magnitude (3)
91- 92 A2 --- u_Dmag [ :] Uncertainty flag on Dmag
94-101 A8 --- Notes Notes (4)
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Note (1): The years of the observations correspond to the interval 1991-2004.
Note (2): Measured toward the east of north.
Note (3): Differential magnitude of the candidate companion with respect
to the target star.
Note (4): The flags are:
1 = No common proper motion companion after comparison with POSS2 red plates.
2 = No "color" companion.
3 = No proper motion companion.
4 = Previously known common proper motion companion.
5 = Newly identified common proper motion companion.
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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- 10 A10 --- Name Name of the target star
12- 80 A69 --- Note Note
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Acknowledgements: Maria Rosa Zapatero Osorio
(End) Maria Rosa Zapatero Osorio [LAEFF-INTA, Spain] 27-Apr-2004