J/A+A/601/A133 BVRI light curves of 3 massive binaries (Raucq+, 2017)
Observational signatures of past mass-exchange episodes in massive binaries :
The case of LSS 3074.
Raucq F., Gosset E., Rauw G., Manfroid J., Mahy L., Mennekens N.,
Vanbeveren D.
<Astron. Astrophys. 601, A133 (2017)>
=2017A&A...601A.133R 2017A&A...601A.133R (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Photometry, UBVRI
Keywords: stars: early-type - stars: fundamental parameters - stars: massive -
stars: individual: LSS 3074 - binaries: eclipsing -
binaries: spectroscopic
Abstract:
The role of mass and momentum exchanges in close massive binaries is
very important in the subsequent evolution of the components. Such
exchanges produce several observational signatures such as
asynchronous rotation and altered chemical compositions, that remain
after the stars detach again.
We investigated these effects for the close O-star binary LSS 3074
(O4f+O6-7:(f):), which is a good candidate for a past Roche lobe
overflow (RLOF) episode because of its very short orbital period,
P=2.185-days, and the luminosity classes of both components.
We determined a new orbital solution for the system. We studied the
photometric light curves to determine the inclination of the orbit and
Roche lobe filling factors of both stars. Using phase-resolved
spectroscopy, we performed the disentangling of the optical spectra of
the two stars. We then analysed the reconstructed primary and
secondary spectra with the CMFGEN model atmosphere code to determine
stellar parameters, such as the effective temperatures and surface
gravities, and to constrain the chemical composition of the
components.
We confirm the apparent low stellar masses and radii reported in
previous studies. We also find a strong overabundance in nitrogen and
a strong carbon and oxygen depletion in both primary and secondary
atmospheres, together with a strong enrichment in helium of the
primary star.
We propose several possible evolutionary pathways through a RLOF
process to explain the current parameters of the system. We confirm
that the system is apparently in overcontact configuration and has
lost a significant portion of its mass to its surroundings. We suggest
that some of the discrepancies between the spectroscopic and
photometric properties of LSS 3074 could stem from the impact of a
strong radiation pressure of the primary.
Description:
The photometric data of LSS 3074, HD 116827 and LSS 3072 are provided.
These data were obtained with the ANDICAM camera equiped on the Yale
1m telescope at the Cerro Tololo International Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 45 3 List of studied stars
tablea1.dat 19 418 Photometric data of LSS 3074
tablea2.dat 19 375 Photometric data of HD 116827
tablea3.dat 19 420 Photometric data of LSS 3072
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See also:
J/A+A/590/A85 : Massive LMC eclipsing binaries minima timings (Zasche+, 2016)
J/ApJ/748/96 : Massive binaries in the LMC (Massey+, 2012)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 12 I2 h RAh Right ascension (J2000)
14- 15 I2 min RAm Right ascension (J2000)
17- 21 F5.2 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 33 F4.1 arcsec DEs Declination (J2000)
35- 45 A11 --- FileName Name of the file with photometry
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Byte-by-byte Description of file: tablea1.dat tablea2.dat tablea3.dat
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Bytes Format Units Label Explanations
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1 A1 --- Band [BVRI] Observed band
3- 11 F9.4 d HJD Date of the observation (HJD-2450000)
13- 19 F7.4 --- mag Magnitude in Band
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Acknowledgements:
Francoise Raucq, fraucq(at)doct.ulg.ac.be
(End) Francoise Raucq [Liege University], Patricia Vannier [CDS] 06-Mar-2017