J/A+A/336/263 Radial velocities of HR 4049 (Bakker+ 1998)
Spectral variability of the binary HR 4049
Bakker E.J., Lambert D.L., Van Winckel H., McCarthy J.K., Waelkens C.,
Gonzalez G.
<Astron. Astrophys. 336, 263 (1998)>
=1998A&A...336..263B 1998A&A...336..263B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Line Profiles ; Radial velocities
Keywords: line formation - line profiles - AGB and post-AGB stars -
close binaries - stars: emission line, Be - individual stars: HR 4049
Abstract:
The C I, Na I D, and Hα lines of the post-AGB binary HR 4049
have been studied. Na I D variability results from a photospheric
absorption component ([Na/H]=-1.6±0.2) which follows the velocity of
the primary and a stationary, non-photospheric component. An emission
component is attributed to the circumbinary disc, and an absorption
component to mass-loss from the system with a velocity of
5.3±0.5km/s. The Hα profile varies with the orbital period.
The two strong shell type emission peaks are identified as from one
single broad emission feature with an absorption centered around
-7.5km/s. The intensity variations are largely attributed to a
differential amount of reddening towards the Hα emitting region
and the stellar continuum. The radial velocities suggest that the
Hα emission moves in phase with the primary, but with a slightly
lower velocity amplitude. From this we infer that the Hα
emission comes from outside the orbit of the primary, but still
gravitationally bound to the primary. Hα also shows a weak
emission feature at -21.3±3.5km/s, which originates from the
circumbinary disc and a weak absorption feature at -7.5±1.6km/s due
to absorption by the circumbinary disc. We propose two competing
models that could account for the observed velocity and intensity
variations of the Hα profile. Model I: light from the primary
reflects on a localized spot near the inner radius of the circumbinary
disc which is closest to the primary. Model II: Hα emission
originates in the outer layers of the extended atmosphere of the
primary due to activity. These activities are locked to the position
of the primary in its orbit. We discuss the similarities of
variability and shape of the Hα emission of HR 4049 with those
of early type T-Tauri stars (e.g SU Aur).
Objects:
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RA (2000) DE Designation(s)
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10 18 07.6 -28 59 32 HR 4049 = HD 89353
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 49 32 Log of 32 Na I D observations
table4.dat 47 60 Log of 60 Hα observations
tables.tex 109 132 LaTeX version of the tables
fig12.ps 76 1675 *Observed NaI D2 line profiles in order of
relative orbital phase φrel
fig13.ps 76 2386 Figure 12 continued
fig14.ps 76 2297 *Observed Hα line profiles in order of
relative orbital phase φrel
fig15.ps 76 2301 Figure 14 continued
fig16.ps 76 2309 Figure 14 continued
fig17.ps 76 2036 Figure 14 continued
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Note on fig12.ps: The systemic velocity of the binary, γs=-32.15km/s, is
at zero (solid line) with on both sides a short-dashed line at the extreme
velocity of the star in its orbit. The long-dashed lines correspond to the
velocity of that star.
The measured velocities and intensities of the marker points are marked. The
photospheric component (on the profile, only if measured) and the predicted
stellar velocity (at an intensity of 1.0) have both been plotted with a dot.
These two points can be at different velocities because the photospheric
velocity cannot be very well determined from the observed NaI D2 profile.
The circumsystem markers (diamond and triangle) and the interstellar markers
(crosses) have been marked. In each window, the upper left corner gives the
absolute orbital phase and the upper right corner the telescope/instrument
with which the spectrum was obtained.
Note on fig14.ps: The systemic velocity of the binary, γs=-32.15km/s,
is at zero (solid line) with on both sides a short-dashed line at the extreme
velocity of the star in its orbit. The long-dashed lines correspond to the
velocity of that star.
The "blue maximum" (cross), "blue minimum" (open square), "central maximum"
(open triangle), "red minimum" (open diamond), and "red maximum" (asterisk)
have been marked. In each window, the upper left corner gives the absolute
orbital phase and the upper right corner the telescope/instrument with which
the spectrum was obtained.
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See also:
J/A+A/306/924 : Optical spectrum of HR 4049 (Bakker+, 1996), Paper I.
Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 "DD/MM/YY" Date Observation date
10- 20 F11.3 d HJD Heliocentric Julian date
22- 25 F4.2 --- φabs Phase (1)
27- 35 A9 --- Tel/Instr Telescope/Instrument (2)
37- 42 I6 --- R Spectral resolving power
44- 49 F6.2 km/s HRV Heliocentric radial velocity (3)
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Note (1): φabs=0.0 at HJD=T0=2446746.6±2.4
Note (2): CAT/CES: Twenty-three Hα and two Na I D single-order spectra
(R∼55,000) have been obtained by HvW and CW on the ESO
observatory at La Silla (Chili) using the coude echelle
spectrograph at the 1.4m Coude Auxiliary Telescope.
McD/CS11: Twenty-three Hα and twenty-one Na I D single-order
spectra (R∼60,000) have been obtained by DLL, JKM, and
Jos Tomkin using the echelle spectrograph (6-foot
camera) on the 2.7m McDonald telescope.
McD/CE: Ten multi-order spectra (R∼45,000) have been obtained by GG
using the Sandiford cassegrain echelle spectrograph
(McCarthy et al., 1993PASP..105..881M 1993PASP..105..881M) on the 2.1m McDonald
telescope. Eight contain Hα and four Na I D.
WHT/UES: Three multi-order spectra (R∼50,000) have been obtained in
service time using the Utrecht echelle spectrograph on the
4.2m William Herschel telescope on La Palma (Unger, 1994,
La Palma Technical Notes No. XXIII). All three spectra
contain Hα, Na I D, and numerous photospheric
absorption lines. An extensive analysis of these spectra and
complete line identification have been published in Paper I
(Bakker et al., 1996, Cat. J/A+A/306/924).
McD/CS21: Two multi-order spectra (R∼160,000) have been obtained by EJB
using the cross-dispersed echelle spectrograph
(Tull et al., 1995PASP..107..251T 1995PASP..107..251T) at the 2.7m McDonald
telescope. Both contain Hα and Na I D.
CTIO/ES: One single-order Hα spectrum (R∼18,000) has been
obtained by Andy McWilliam using the echelle spectrograph
with the air Schmidt camera on the 4m CTIO telescope.
Note (3): In table3.dat, heliocentric radial velocities are computed using the
orbital parameters
In table4.dat, heliocentric radial velocities are measured from CI,
N I, and O I lines; the velocity accuracy is 2km/s
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Acknowledgements: Eric J. Bakker
(End) Patricia Bauer [CDS] 05-Mar-1998