J/AJ/107/1577 Halo red giants reddening (Anthony-Twarog+, 1994)
Reddening estimation for halo red giants using uvby photometry
Anthony-Twarog B.J., Twarog B.A.
<Astron. J. 107, 1577 (1994)>
=1994AJ....107.1577A 1994AJ....107.1577A
ADC_Keywords: Photometry, uvby ; Stars, metal-deficient
Abstract:
Updated uvby observations for a larger sample of metal-deficient red
giants are presented and combined with a select sample of data from
the literature transformed to a common system. Using the reddening
maps of Burstein & Heiles [AJ, 87, 1165 (1982)], new absolute
magnitudes, distances, metallicities, and reddenings are derived for
each star. The metallicities are determined with a revised calibration
of the m1, (b-y) diagram based upon comparison to a compilation of
recent spectroscopic abundances transformed to a common system. The
photometric abundances agree very well with the spectroscopic; the
dispersion among the residuals for 58 giants is ±0.16dex. The
dereddened indices are used to show that for red giants with
[Fe/H]←1.5, there is a well-defined relation in the c0, (b-y)0
diagram which exhibits only a weak dependence upon metallicity. Use of
the standard relations allows one to obtain reddening estimates for
normal halo field giants and globular clusters in the appropriate
metallicity range.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 114 uvby photometry of metal-deficient giants
table5a.dat 53 114 Derived parameters from table1
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See also:
J/AJ/109/2828 : CaII H and K filter photometry II. (Twarog+ 1995)
Byte-per-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Identification (1)
11- 16 F6.3 mag Vmag [6.7/14.2] Visual magnitude
18- 22 F5.3 mag e_Vmag Standard deviation in V (2)
24- 28 F5.3 mag b-y b-y color index on the Stromgren system
30- 34 F5.3 mag e_b-y Standard deviation in b-y (2)
36- 37 I2 --- o_b-y Number of observations for V and b-y (3)
39- 43 F5.3 mag m1 m1 index
45- 49 F5.3 mag e_m1 Standard deviation in m1 (2)
51- 55 F5.3 mag c1 c1 index
57- 61 F5.3 mag e_c1 Standard deviation in c1 (2)
63- 64 I2 --- o_c1 Number of observations for m1 and c1 (3)
66 I1 --- n_ID [1/2]? Note flag (1)
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Note (1): Henry Draper, Durchmusterung, or other identification if n_ID is:
1 = Identification from Beers et al. 1992, Cat. J/AJ/103/198
2 = Identification from Beers et al. 1992, Cat. J/AJ/103/1987
is a brighter giant located near a potential metal-deficient
program star; its approximate position is 23:24:00-02:55:58 (B1950).
The actual program star proved to be too faint to produce reliable
photometry.
[Note added at CDS in July 2016: this star is 2MASS J23263267-0239363]
Note (2): Errors listed for the magnitude and the indices are standard
deviations for a single observation; the standard deviations have been
set to 0.000 for stars with only one observation (in field o_b-y or
o_c1). It should be emphasized that the probable photometric errors
for the stars with V>13.0 and only one observation are significantly
larger than implied by the brighter stars.
Note (3): Because the stars were also included in the Caby photometric
program (Anthony-Twarog et al. 1991, AJ, 101, 1902), many of the stars
have a larger number of V and (b-y) (field N1) than m1 and c1 (field N2).
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Byte-per-byte Description of file: table5a.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Identification
11 A1 --- n_E(b-y) [ *] Note for derived reddening (4)
13- 17 F5.3 mag E(b-y) ? Reddening
20- 24 F5.2 mag Mv ? Absolute magnitude
26- 30 I5 pc R ? Distance
32 A1 --- l_[Fe/H] Limit flag for [Fe/H]
33- 37 F5.2 [Sun] [Fe/H] Metallicity
40- 44 F5.2 [Sun] [Fe/H]s ? Average spectroscopic abundance
48- 51 F4.2 [Sun] e_[Fe/H]s ? Dispersion in [Fe/H]s
53 I1 --- N ? Number of estimates included in [Fe/H]s
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Note (4): An asterisk, '*', indicates that the derived reddening, E(b-y) is
from comparisons to the standard c0,(b-y)0 relations, as described in
Section 4.3 of the printed paper.
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Addresses:
Anthony-Twarog B.J. and Twarog B.A. anthony at kuphsx.phsx.ukans.edu
Department of Physics and Astronomy, University of Kansas,
Lawrence, Kansas 66045-2151
Origin: AAS CD-ROM series, Volume 2, 1994
(End) Lee Brotzman [ADS] 08-May-1994, Patricia Bauer [CDS] 24-Oct-1994