J/A+A/335/565 Be stars variability (Hubert+ 1998)
Investigation of the variability of bright Be stars using Hipparcos photometry
Hubert A.M., Floquet M.
<Astron. Astrophys. 335, 565 (1998)>
=1998A&A...335..565H 1998A&A...335..565H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, Be ; Stars, variable
Keywords: stars: emission-line, Be - oscillations - statistics -
variables: other
Abstract:
The high accuracy and the homogeneity of Hipparcos data for bright
stars have allowed us to quantify the degree of variability of Be
stars. This degree has been found to be highly dependent on the
temperature of the star. Rapid variability is the main feature of the
86% of early Be and less than 20% of late Be stars taking into account
the limit of detection considered. In addition to Be stars reported in
the Hipparcos catalogue (ESA 1997, Cat. I/239) as short-period
variables, we have been able to enlarge the number of detections as
well as to confirm periods previously determined. Be stars that show
larger amplitude rapid variations are proposed as candidates for a
search of multiperiodicity i.e. as non-radial pulsators. We have also
searched for the presence of outbursts and fading events in the
Hipparcos data. Outbursts have been frequently and preferentially
detected in early Be stars with rather low to moderate v sini while
fading events seem to be more conspicuous in stars with higher v sini.
Mid-term and long-term variations have also been investigated. Several
stars have shown some evidence of temporary quasi-periodic
oscillations ranging between 10 and 200 days. Finally information
concerning long-term variations is reported. Cycles shorter than or
equal to the Hipparcos mission have mainly been detected in stars
earlier than B6. Long-term time scales of late Be stars are confirmed
to be longer by far.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 124 46 Short-term variability of Be stars using FT+CLEAN
table2.dat 131 14 Short-term periodicity of Be stars given by
Hipparcos catalogue (Cat. I/239)
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD (Cat. III/135) number
8- 18 A11 --- Name Star's name
20- 23 F4.2 mag Vmag V magnitude
24 A1 --- n_Vmag [*] Note on Vmag (1)
26- 34 A9 --- SpType Spectral type of the star (2)
36- 65 A30 --- Var Long-term variation
68 A1 --- l_Per Limit flag on Per
69- 73 F5.3 d Per Period of short-term variations
74 A1 --- --- [/] Dash
75- 79 F5.3 d Per2 ? Second period of short-term variations
80 A1 --- u_Per [?] Uncertainty flag on Per
81- 82 A2 --- n_Per [DW ] DW when light curve presents a double wave
84-131 A48 --- Rem Remarks (3)
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Note (1): *: The V magnitude given by Hipparcos is the magnitude of the
photocenter of this multiple system
Note (2): Sources of the spectral classification are
Jaschek et al. (1980A&AS...42..103J 1980A&AS...42..103J),
Slettebak (1982ApJS...50...55S 1982ApJS...50...55S) and
Zorec & Briot (1991A&A...245..150Z 1991A&A...245..150Z).
Note (3): References:
1- Bozic et al., 1995, Cat. J/A+A/304/235
2- Percy et al., 1994PASP..106..131P 1994PASP..106..131P
3- Dachs & Lemmer 1991, in "Rapid Variability of OB stars: Nature and
Diagnostic Value", Garching, p 103
4- Stefl & Balona, 1996, Cat. J/A+A/309/787
5- Balona et al., 1992A&AS...92..533B 1992A&AS...92..533B
6- Yang et al., 1990ApJS...74..595Y 1990ApJS...74..595Y
7- Kaye & Gies, 1997ApJ...482.1028K 1997ApJ...482.1028K
8- Balona, 1995MNRAS.277.1547B 1995MNRAS.277.1547B
9- Barrera et al., 1991Ap&SS.185...79B 1991Ap&SS.185...79B
10- Cuypers et al., 1989A&AS...81..151C 1989A&AS...81..151C
11- Stagg et al., 1988MNRAS.234.1021S 1988MNRAS.234.1021S
12- Bossi et al., 1989IBVS.3348....1B 1989IBVS.3348....1B
13- Balona et al., 1992A&AS...92..533B 1992A&AS...92..533B
14- Stefl et al., 1995, Cat. J/A+A/294/135
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Acknowledgements: Michele Floquet
(End) Patricia Bauer [CDS] 31-Mar-1998