J/PAZh/37/781 Abundances of 7 southern-hemisphere Cepheids (Usenko+, 2011)
Spectroscopic studies of southern-hemisphere Cepheids:
WW Car, SX Car, UZ Car, UY Car, GX Car, HW Car, YZ Car.
Usenko I.A., Berdnikov L.N., Kravtsov V.V., Kniazev A.Yu., Chini R.,
Hoffmeister V.H., Stahl O., Drass H.
<Pis'ma Astron. Zh. 37, 781 (2011)>
=2011PAZh...37..781U 2011PAZh...37..781U
=2011AstL...37..718U 2011AstL...37..718U
ADC_Keywords: Stars, variable ; Abundances
Keywords: Cepheids, spectra, atmospheric parameters, chemical composition
Abstract:
For seven faint southern Cepheids (WW Car, SX Car, UZ Car, UY Car, GX
Car, HW Car, YZ Car), we have determined their atmospheric parameters
and chemical composition for the first time based on ten
high-resolution (R=50000) spectra taken with the 1.5-m Hexapod
telescope at the Joint Observatory of the Northern Catholic University
(Antofagasta, Chile) and the Ruhr University (Bochum, Germany). Six
objects from the list demonstrate atmospheric parameters and chemical
composition typical of Cepheids that have passed through the first
dredge-up phase, while WW Car is probably an anomalous Cepheid.
According to our preliminary estimates, it has an overabundance of
CNO, a deficit of sodium and aluminium, and a slight deficit of
magnesium, with iron and other elements being underabundant relative
to the Sun.
Description:
Our spectroscopic observations of the program stars were performed at
the Joint Observatory of the Northern Catholic University and the Ruhr
University (Bochum) near Cerro Armazones in Chile.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table12.dat 89 10 Information about the program Cepheids and their
observations, atmospheric parameters and
light elements (tables 1-2 of the paper)
abund.dat 29 367 Elemental abundances (tables 3-5 of the paper)
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See also:
J/A+A/305/551 : Chemical composition of the s-Cepheids (Andrievsky+, 1996)
J/AJ/113/1073 : Abundances in Cepheid Variables (Fry+ 1997)
J/AJ/114/341 : Type II Cepheids (Gonzalez+ 1997)
J/A+A/381/32 : Galactic Cepheid abundances (Andrievsky+, 2002)
J/A+A/392/491 : Galactic abundance gradient. III. (Andrievsky+, 2002)
J/A+A/413/159 : Galactic abundance gradient. V. (Andrievsky+, 2004)
J/AJ/128/343 : Abundances of 10 Cepheids (Luck+, 2004)
J/AJ/129/433 : Abundances & equivalent widths of 14 Cepheids (Kovtyukh+, 2005)
J/AJ/130/1880 : Cepheids with periods between 3 and 6 days (Andrievsky+, 2005)
J/AJ/132/902 : Abundances of 54 Cepheids (Luck+, 2006)
Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Cepheid name
8- 9 I2 h RAh Right ascension (J2000.0)
11- 12 I2 min RAm Right ascension (J2000.0)
14- 17 F4.1 s RAs Right ascension (J2000.0)
19 A1 --- DE- Declination sign (J2000.0)
20- 21 I2 deg DEd Declination (J2000.0)
23- 24 I2 arcmin DEm Declination (J2000.0)
26- 27 I2 arcsec DEs Declination (J2000.0)
29- 32 F4.1 mag Vmag V magnitude
34 I1 --- NObs [1/3] Number of the observation
36- 44 F9.4 d ObsDate Observation date (HJD-2450000)
46- 47 I2 --- S/N Signal-to-noise ratio of the observation
49- 52 I4 K Teff Effective temperature
54- 55 I2 K e_Teff rms uncertainty on Teff
57- 60 F4.2 [cm/s2] logg Surface gravity
62- 65 F4.2 km/s Vt Turbulent velocity
67- 75 F9.4 d tmax ? Initial time of maximum (HJD-2450000)
77- 83 F7.4 d Per ? Period
85- 89 F5.3 --- Phase Phase (associated to observation)
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Byte-by-byte Description of file: abund.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Cepheid name
8 I1 --- NObs [1/3] Number of the observation
10- 14 A5 --- El Element
16- 20 F5.2 [-] [El/H] ?=- Elemental abundance
22- 25 F4.2 [-] e_[El/H] ?=- rms uncertainty on [El/H]
27- 29 I3 --- NL ? Number of lines used
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Nov-2011