J/A+A/372/245 Infrared properties of barium stars (Chen+, 2001)
Infrared properties of barium stars
Chen P.S.
<Astron. Astrophys. 372, 245 (2001)>
=2001A&A...372..245C 2001A&A...372..245C
ADC_Keywords: Stars, late-type ; Stars, barium ; Infrared sources ;
Spectra, infrared
Keywords: stars: late-type - infrared: stars - stars: chemically peculiar
Abstract:
We present the results of a systematic survey for IRAS associations of
barium stars. A total of 155 associations were detected, and IRAS
low-resolution spectra exist for 50 barium stars. We use different
color-color diagrams from the visual band to 60µm, relations
between these colors and the spectral type, the barium intensity, and
the IRAS low-resolution spectra to discuss physical properties of
barium stars in the infrared. It is confirmed that most barium stars
have infrared excesses in the near infrared. However, a new result of
this work is that most barium stars have no excesses in the far
infrared. This fact may imply that infrared excesses of barium stars
are mainly due to the re-emission of energy lost from the Bond-Neff
depression. It is also shown that the spectral type and the barium
intensity of barium stars are not correlated with infrared colors, but
may be correlated with V-K color.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 154 155 IRAS associations of barium stars
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See also:
V/81 : Taxonomy of Barium Stars (Lu 1991)
III/197 : IRAS Low Resolution Spectra (IRAS team, 1987)
I/254 : The HST Guide Star Catalog, Version 1.2 (Lasker+ 1996)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Star Star number from Lu (1991, Cat. V/81)
5- 13 A9 --- HD HD name (HD NNNNNN)
15- 16 I2 h RAh Right ascension (1950) from the GSC
18- 19 I2 min RAm Right ascension (1950) from the GSC
21- 25 F5.2 s RAs Right ascension (1950) from the GSC
27 A1 --- DE- Declination sign (1950) from the GSC
28- 29 I2 deg DEd Declination (1950) from the GSC
31- 32 I2 arcmin DEm Declination (1950) from the GSC
34- 37 F4.1 arcsec DEs Declination (1950) from the GSC
39- 43 F5.2 mag Vmag B or V magnitude from the GSC
44 A1 --- u_Vmag [)] Uncertainty flag on Vmag
45- 49 F5.2 mag Kmag ? K magnitude from the IRC or from others
(indicated in r_Kmag)
51- 58 A8 --- SpType Spectral type from Lu (1991, Cat. V/81)
60- 62 F3.1 --- Ba Barium intensity from Lu (1991, Cat. V/81)
63 A1 --- u_Ba Uncertainty flag on Ba
65 A1 --- LRS [FIS] LRS classification from Kwok et al.
(1997, Cat. J/ApJS/112/557) (1)
67- 68 I2 --- LRSa ? LRS Atlas characteristics (Cat. III/197)
71- 77 F7.3 mJy F12 ? 12µm IRAS flux density (3)
79- 85 F7.3 mJy F25 ? 25µm IRAS flux density (3)
87- 92 F6.3 mJy F60 ? 60µm IRAS flux density (3)
94- 99 F6.3 mJy F100 ? 100µm IRAS flux density (3)
101-106 A6 --- IRC ? IRC number (Cat. II/2)
107 A1 --- r_Kmag [a-g] References for Kmag (4)
109-123 A15 --- IRAS IRAS name (IRAS NNNNN+NNNN)
126-127 I2 h RA2h Right ascension (1950) from IRAS (Cat. II/125)
129-130 I2 min RA2m Right ascension (1950) from IRAS (Cat. II/125)
132-135 F4.1 s RA2s Right ascension (1950) from IRAS (Cat. II/125)
137 A1 --- DE2- Declination sign (1950) from IRAS
138-139 I2 deg DE2d Declination (1950) from IRAS (Cat. II/125)
141-142 I2 arcmin DE2m Declination (1950) from IRAS (Cat. II/125)
144-147 F4.1 arcsec DE2s Declination (1950) from IRAS (Cat. II/125)
149-153 F5.3 mag V2mag B or V magnitude from Lu (1991, Cat. V/81)
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Note (1): LRS classification:
F: The LRS spectra show a featureless continuum, flatter than that
expected of a stellar photosphere. They probably represent
evolved oxygen- or carbon-rich stars with small amounts of
circumstellar dust.
I: Noisy or incomplete spectra, including cases in which the two
parts of the spectra seem to be copies of each other. When this
occurs, the different flux and wavelength calibrations cause the
red part to be a magnified, slightly distorded copy of the blue
part. Some of these sources can be classified from the blue part
of the spectrum but have no useful red scans in the database.
S: The LRS spectra closely approximate the Rayleigh-Jeans tails of
the stellar photospheric continuum. The sources are usually stars
with spectral types earlier than M5, without substantial mass
loss.
Note (3): Only good quality ones are presented
Note (4): References for K magnitude:
(a) Hakkila et al. (1987A&A...186..255H 1987A&A...186..255H)
(b) Mcgregor et al. (1984ApJ...277..149M 1984ApJ...277..149M)
(c) Price (1968AJ.....73..431P 1968AJ.....73..431P)
(d) Engels et al. (1981A&AS...45....5E 1981A&AS...45....5E)
(e) Elias (1978AJ.....83..791E 1978AJ.....83..791E)
(f) Hartoog et al. (1977PASP...89..660H 1977PASP...89..660H)
(g) Leggett et al. (1988MNRAS.234.1065L 1988MNRAS.234.1065L)
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Acknowledgements: P.S. Chen
(End) Patricia Bauer [CDS] 06-Apr-2001