J/A+A/550/A93 VI light curves of V383 Sco (Galan+, 2013)
A new look at the long-period eclipsing binary V383 Scorpii.
Galan C., Tomov T., Kato T., Pojmanski G., Szczygiel D.M., Pilecki B.,
Graczyk D., Gromadzki M., Mikolajewski M., Gieren W., Strobel A.,
Roukema B.F.
<Astron. Astrophys. 550, A93 (2013)>
=2013A&A...550A..93G 2013A&A...550A..93G
ADC_Keywords: Binaries, eclipsing ; Photometry, VRI
Keywords: binaries: eclipsing - circumstellar matter - stars: mass-loss -
stars: oscillations - stars: winds, outflows
Galaxy: kinematics and dynamics
Abstract:
The system V383 Sco was discovered to be an eclipsing binary star at
the beginning of the twentieth century. This system has one of the
longest orbital periods known (13.5yr) and was initially classified
as a zeta Aur-type eclipsing variable. It was then forgotten about for
decades, with no progress made in understanding it.
This study provides a detailed look at the system V383 Sco, using new
data obtained before, during and after the last eclipse, which
occurred in 2007/8. There was a suspicion that this system could be
similar to eclipsing systems with extensive dusty disks like EE Cep
and epsilon Aur. This and other, alternative hypotheses are considered
here.
The All Sky Automated Survey (ASAS-3) V and I light curves have been
used to examine apparent magnitude and colour changes. Low- and high-
resolution spectra have been obtained and used for spectral
classification, to analyse spectral line profiles, as well as to
determine the reddening, radial velocities and the distance to the
system. The spectral energy distribution (SED) was analysed using all
available photometric and spectroscopic data. Using our own original
numerical code, we performed a very simplified model of the eclipse,
taking into account the pulsations of one of the components.
The low-resolution spectrum shows apparent traces of molecular bands,
characteristic of an M-type supergiant. The presence of this star in
the system is confirmed by the SED, by a strong dependence of the
eclipse depth on the photometric bands, and by the nature of
pulsational changes. The presence of a very low excitation nebula
around the system has been inferred from [OI] 6300Å emission in the
high-resolution spectrum. Analysis of the radial velocities,
reddening, and period-luminosity relation for Mira-type stars imply a
distance to the V383 Sco system of 8.4±0.6kpc. The distance to the
nearby V381 Sco is 6.4±0.8kpc. The very different and oppositely
directed radial velocities of these two systems (89.8km/s vs
-178.8km/s) seem to be in agreement with a bulge/bar kinematic model
of the Galactic centre and inconsistent with purely circular motion.
Conclusions. We have found strong evidence for the presence of a
pulsating M-type supergiant in the V383 Sco system. This supergiant
periodically obscures the much more luminous F0 I-type star, causing
the deep (possibly total) eclipses which vary in duration and shape.
Description:
We present Johnson's V- and I-band photometry obtained for V383 Sco
long period eclipsing binary by the ASAS-3 photometric survey during
the years 2001-2009
Objects:
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RA (2000) DE Designation(s)
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17 53 34.450 -38 05 00.67 V383 Sco = HV 7021
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 28 504 Johnson V-band photometric data of V383 Sco
obtained by the ASAS-3 survey during the years
2001-2009
tableb2.dat 28 245 Johnson I-band photometric data of V383 Sco
obtained by the ASAS-3 survey during the years
2002-2009
tableb3.dat 19 97 V-I colour indices obtained from data of tables
B1 and B2 when both the V and I measurements on
the same night were available
tableb4.dat 19 86 V-I colour indices obtained from data of tables
B1 and B2 via interpolation in the cases when
close measurements in V and I bands were used
while the simultaneous measurements on the
same night were not available
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian date
15- 20 F6.3 mag Vmag Johnson V-band photometry
22- 26 F5.3 mag e_Vmag Error of Vmag
28 A1 --- Grade [A-D] Quality flags,
where A denotes the highest one
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian date
15- 20 F6.3 mag Imag Johnson I-band photometry
22- 26 F5.3 mag e_Imag Error of Imag
28 A1 --- Grade [A-D] Quality flags,
where A denotes the highest one
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Byte-by-byte Description of file: tableb3.dat tableb4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian date
15- 19 F5.3 mag V-I V-I colour index
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Acknowledgements:
Cezary Galan,
(End) Patricia Vannier [CDS] 02-Jan-2013