J/A+A/307/869 Nature of the peculiar supergiant HD 101584 (Bakker+, 1996)
A study on the nature of the peculiar supergiant HD 101584
Bakker E.J., Lamers H.J.G.L.M., Waters L.B.F.M., Waelkens C.,
Trams N.R., van Winckel H.
<Astron. Astrophys. 307, 869 (1996)>
=1996A&A...307..869B 1996A&A...307..869B (SIMBAD/NED BibCode)
ADC_Keywords: Spectroscopy ; Spectra, ultraviolet
Keywords: line: identification - stars: fundamental parameters -
individual: HD 101584; mass-loss; peculiar; AGB and Post-AGB
Description:
We present a study of low- and high-resolution ultraviolet,
high-resolution optical CAT/CES spectra and ultraviolet, optical and
infrared photometry of the peculiar supergiant HD 101584. From the
photometry we learn that the ultraviolet and optical energy
distribution cannot be fitted in a consistent way and we need
a model in which the UV and optical energy distribution are formed by
different gas. The Geneva photometry is best fitted to a B9II Kurucz
model, Teff=12000±1000K and logg=3.0±1.0, with an extinction of
E(B-V)=0.49±0.05. The observed spectral features in the spectrum of
HD 101584 are classified in eight different categories based on the
velocity, shape of profile and the identification. The
high-excitation HeI (χ=20.87eV), NII (χ=18.40eV),
CII (χ=14.39eV) and NI (χ=10.29eV) optical absorption lines are
formed in the photosphere of a late B-star (e.g. B8-9I-II). These
absorption lines show radial velocity variations which are attributed
to binary motion, with the secondary being a white dwarf or a
low-mass main sequence object. The low-excitation P-Cygni lines in the
optical and UV are formed in the wind. The number density of
absorption lines in the UV is so large that the wind spectrum acts as
an iron curtain in front of the B-star. The terminal velocity of the
wind of v∞=100±30km/s is consistent with the star being
a low-mass post-AGB star and the low effective gravity is attributed
to the presence of a nearby, unseen, secondary. We estimate a mass-loss
rate of M{dot}≃10-8M☉/yr. Narrow absorption and emission
lines are observed which are formed in a circumsystem disk with a
typical radius of 102R*.
Objects:
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RA (2000) DE Designation(s)
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11 40 58.8 -55 34 26 HD 101584 = HIC 56992 = IRAS 11385-5517
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table14 53 19 19 selected UV FeII absorption lines of
HD 101584 and alpha Lep
table15 126 251 The optical spectrum of HD 101584
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Table1: Ultraviolet spectra of HD 101584
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Camera Observation Wavelength range
Image No. Date 0.1nm
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Low-resolution IUE spectra
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SWP31025 22 May 1987 1191 - 1950
LWP10808 22 May 1987 1951 - 2551
LWP10809 22 May 1987 2552 - 3199
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High resolution IUE spectra
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LWP17369 15 Febr 1990 2500 - 3000
LWR04822 21 June 1979 2500 - 3000
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Byte-by-byte Description of file: table14
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Bytes Format Units Label Explanations
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2- 9 F8.3 0.1nm LamLab Laboratory wavelength
13- 15 I3 --- Multiplet Multiplet number
19- 22 F4.2 eV Chi Lower level excitation energy of the
transition
26- 30 F5.2 --- log(gf) The oscillator strength of the transition
34- 35 I2 km/s HRV1 Radial heliocentric velocity of the
absorption feature of HD 101584
(High-resolution ultraviolet spectrum
LWP17369) (1)
43- 44 I2 km/s HRV2 []? Radial heliocentric velocity of the
absorption feature of HD 101584
(High-resolution ultraviolet spectrum
LWR04822) (1)
52- 53 I2 km/s HRV3 Radial heliocentric velocity of the
absorption feature of the comparison star
α Lep (High-resolution ultraviolet
spectrum LWR3236) (1)
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Note (1): See Table1
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Byte-by-byte Description of file: table15
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Bytes Format Units Label Explanations
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3- 6 I4 0.1nm LamO Minimum value observed wavelength
7 A1 --- Sep1 [-] Interval separation sign
8- 11 I4 0.1nm Lam1 Maximum value observed wavelength
14- 21 A8 "DD/MM/YY" Date Date of observation
25- 33 A9 --- Multiplet Element and multiplet number
35- 42 F8.3 0.1nm LamLab []? Laboratory wavelength
44- 48 F5.2 eV Chi1 []? Lower level excitation energy,
first value
49 A1 --- Sep2 [-] Interval separation sign
50- 54 F5.2 eV Chi2 []? Lower level excitation energy,
second value
56- 60 F5.2 --- log(gf) []? Oscillator strength
62- 68 F7.2 0.1nm LamObs Observed wavelength
72- 73 I2 km/s HRV(I) []? Radial heliocentric velocity for
the identified absorption feature:
Type I
74 A1 --- u_HRV(I) [:] Uncertainty flag on HRV(I)
77- 79 I3 km/s HRV(II) []? Radial heliocentric velocity for
the identified absorption feature:
Type II
80 A1 --- u_HRV(II) [:] Uncertainty flag on HRV(II)
83- 85 I3 km/s HRV(III) []? Radial heliocentric velocity for
the identified absorption feature:
Type III
86 A1 --- u_HRV(III) [:] Uncertainty flag on HRV(III)
87- 89 I3 km/s HRV(IV) []? Radial heliocentric velocity for
the identified absorption feature:
Type IV
93- 95 I3 km/s HRV(V) []? Radial heliocentric velocity for
the identified emission feature: Type V
96 A1 --- u_HRV(V) [:] Uncertainty flag on HRV(V)
99-102 I4 km/s HRV(VI) []? Radial heliocentric velocity for
the identified emission feature: Type VI
103 A1 --- u_HRV(VI) [:] Uncertainty flag on HRV(VI)
104-108 I5 0.1pm EW []? Observed equivalent width
110-113 I4 % Depth []? Depth of the central absorption
relative to the continuum
115-126 A12 --- Remark Remark
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(End) Simona Mei [CDS] 26-Jul-1995