J/A+A/557/A1 Bright B-type variables in Scorpius (Handler+, 2013)
Time-resolved multicolour photometry of bright B-type variable stars in
Scorpius.
Handler G., Schwarzenberg-Czerny, A.
<Astron. Astrophys. 557, A1 (2013)>
=2013A&A...557A...1H 2013A&A...557A...1H
ADC_Keywords: Stars, B-type ; Stars, variable ; Binaries, eclipsing ;
Stars, supergiant ; Photometry, uvby
Keywords: stars: oscillations - binaries: eclipsing - stars: early-type -
stars: variables: general - techniques: photometric
Abstract:
The first two of a total of six nano-satellites that will constitute
the BRITE-Constellation space photometry mission have recently been
launched successfully. In preparation for this project, we carried out
time-resolved colour photometry in a field that is an excellent
candidate for BRITE measurements from space. We acquired 117h of
Stromgren uvy data during 19 nights. Our targets comprised the
β Cephei stars κ and λ Sco, the eclipsing binary
µ1 Sco, and the variable super/hypergiant ζ1 Sco. For
κ Sco, a photometric mode identification in combination with
results from the spectroscopic literature suggests a dominant
(l,m)=(1,-1) β Cephei-type pulsation mode of the primary star.
The longer period of the star may be a rotational variation or a
g-mode pulsation. For λ Sco, we recover the known dominant
β Cephei pulsation, a longer-period variation, and observed part
of an eclipse. Lack of ultraviolet data precludes mode identification
for this star. We noticed that the spectroscopic orbital ephemeris of
the closer pair in this triple system is inconsistent with eclipse
timings and propose a refined value for the orbital period of the
closer pair of 5.95189±0.00003d. We also argue that the components
of the λ Sco system are some 30% more massive than previously
thought. The binary light curve solution of µ1 Sco requires
inclusion of the irradiation effect to explain the u light curve, and
the system could show additional low amplitude variations on top of
the orbital light changes. ζ1 Sco shows long-term variability
on a time scale of at least two weeks that we prefer to interpret in
terms of a variable wind or strange mode pulsations.
Description:
Differential time series photometry for all observed stars, relative
to the main comparison star υ Sco is presented. The data have
not been transformed to the standard system.
Time-resolved photometry was carried out at the 0.5-m telescope at the
South African Astronomical Observatory. We were awarded two runs of
two weeks each, separated by two weeks, in July and August 2011. The
photoelectric Modular Photometer that is permanently mounted to this
telescope was used in connection with Stromgren uvy and neutral
density filters.
Objects:
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RA (2000) DE Designation(s)
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17 42 29.28 -39 01 47.9 κ Sco = HD 160578
17 33 36.52 -37 06 13.8 λ Sco = HD 158926
16 51 52.23 -38 02 50.6 µ1 Sco = HD 151890
16 52 20.15 -38 01 03.1 µ2 Sco = HD 151985
16 53 59.73 -42 21 43.3 ζ1 Sco = HD 152236
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 73 5 List of light curves
lc/* . 14 Individual light curves
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See also:
J/A+A/448/1001 : Radial velocities of B stars in Sco-Cen (Jilinski+, 2006)
J/ApJ/756/133 : ScoCen debris disks around B- and A-type stars (Chen+, 2012)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Simbad star name
12- 13 I2 h RAh Simbad Right ascension (J2000)
15- 16 I2 min RAm Simbad Right ascension (J2000)
18- 22 F5.2 s RAs Simbad Right ascension (J2000)
24 A1 --- DE- Simbad Declination sign (J2000)
25- 26 I2 deg DEd Simbad Declination (J2000)
28- 29 I2 arcmin DEm Simbad Declination (J2000)
31- 34 F4.1 arcsec DEs Simbad Declination (J2000)
36- 47 A12 --- uFile Stromgren-u light curve file in subdirectory lc
49- 60 A12 --- vFile Stromgren-v light curve file in subdirectory lc
62- 73 A12 --- yFile Stromgren-y light curve file in subdirectory lc
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
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1- 9 F9.6 d Date Heliocentric Julian Date of mid exposure
(HJD-2455700)
11- 17 F7.4 mag mag Relative magnitude in Filt
19 A1 --- Filt [uvy] Filter
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Acknowledgements:
Gerald Handler, gerald( at )camk.edu.pl, Copernicus Astronomical Center
(End) Gerald Handler [CAMK], Patricia Vannier [CDS] 09-Aug-2013