J/AJ/132/111 BV(RI)Cphotometry of 77 Hyades stars (Joner+, 2006)
Homogeneous photometry for the Hyades: scale-factor and zero-point tests of
previously published BV(RI)Cphotometry.
Joner M.D., Taylor B.J., Laney C.D., Van Wyk F.
<Astron. J., 132, 111-116 (2006)>
=2006AJ....132..111J 2006AJ....132..111J
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, Cousins
Keywords: methods: statistical -
open clusters and associations: individual (Hyades) -
stars: fundamental parameters - techniques: photometric
Abstract:
New BV(RI)C observations of 77 stars in the Hyades are reported and
discussed. The new observations are used to test published magnitudes
and color indices for that cluster. For values of (V-R)C and (R-I)C
published previously by Taylor & Joner (1985AJ.....90..479T 1985AJ.....90..479T and 2005,
Cat. J/ApJS/159/100), the tests reveal no detectable scale-factor
problems. In addition, the tests show that possible zero-point
corrections to the published data can be no larger than a few
millimagnitudes. These test results indicate that future studies
requiring precision photometry for Hyades stars would be well served
by selecting data samples from sources as close as possible to the
native Cousins system. Tests of B-V photometry published by Johnson
& Knuckles (1955ApJ...122..209J 1955ApJ...122..209J) reveal a zero-point ambiguity of
approximately 8mmag in the new data that will require further
measurements to resolve.
Description:
The new measurements were made with the 0.5m telescope and modular
photometer at the Sutherland site of the South African Astronomical
Observatory (SAAO).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 77 New SAAO BV(RI)C data for the Hyades
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See also:
J/A+A/367/111 : A Hipparcos study of the Hyades cluster (de Bruijne+, 2001)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- vB The van Bueren (1952BAN....11..385V 1952BAN....11..385V) number,
Cl Melotte 25 NNN in Simbad
5- 9 I5 --- HIP ? Hipparcos number
11- 21 A11 --- GSC Hubble guide star catalog identification
23- 28 F6.3 mag Vmag ? The V band magnitude
30- 32 F3.1 mmag e_Vmag ? Standard deviation in V (1)
34 A1 --- f_Vmag [eg] Flag on Vmag (2)
36- 40 F5.3 mag B-V The (B-V) color index
42- 44 F3.1 mmag e_B-V Standard deviation in B-V (1)
46- 50 F5.3 mag V-Rc The (V-RC) color index
52- 54 F3.1 mmag e_V-Rc Standard deviation in V-R (1)
56- 60 F5.3 mag Rc-Ic The (R-I)C color index
62- 64 F3.1 mmag e_Rc-Ic Standard deviation in R-I (1)
66- 70 F5.3 mag V-Ic The (V-IC) color index
72- 74 F3.1 mmag e_V-Ic Standard deviation in V-I (1)
76 I1 --- o_Vmag Number of observations
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Note (1): Derived from the scatter for each individual set of measurements.
σ0 is 0.008, 0.007, 0.006, 0.006, and 0.007 mmags for Vmag,
B-V, V-Rc, Rc-Ic, and V-Ic, respectively.
If Vmag>9.0mag, σ0∼0.0155 for Vmag and 0.011 for B-V. For
(V-Ic)=(V-Rc)+(Rc-Ic), σ0=0.007. If σ0<0.010, the
centered 68 per cent confidence interval for σ0 has a width
of ±0.0004 (for Vmag) or ±0.0003 (for the color indices).
Note (2): Flags as follows:
e = For this datum (but not for the color indices), subtract 1
from the listed value of o_Vmag.
g = The SAAO V magnitude for this star is 0.024±0.0083 brighter
than a V magnitude measured by the authors at KPNO.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 31-Aug-2007