J/A+A/520/A89 Multi-epoch photometry of δ Ori (Mayer+, 2010)
Physical elements of the eclipsing binary δ Orionis.
Mayer P., Harmanec P., Wolf M., Bozic H., Slechta M.
<Astron. Astrophys. 520, A89 (2010)>
=2010A&A...520A..89M 2010A&A...520A..89M
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: eclipsing - stars: early type -
stars: fundamental parameters - stars: individual: delta Ori
Abstract:
For years, δ Ori was considered a normal binary with an O9.5 II
primary exhibiting apsidal-line advance. However, in 2002
radial-velocity curves of both binary components derived from the IUE
and optical spectra using the cross-correlation technique have been
published by Harvin et al. (2002ApJ...565.1216H 2002ApJ...565.1216H); surprisingly low
masses of 11.2 and 5.6M☉ were obtained. We obtained new spectra
in the red spectral region and new UBV photometry. Using all published
photometry and radial velocities, we deduced more accurate orbital and
apsidal line periods. The main result of this paper is to show that
the observed line spectra of δ Ori are composed of the lines of
the O9.5 II primary and a similarly hot tertiary, while the lines of a
cooler B-type secondary are too faint to be detected in the available
spectra. The character of the light curve (low-amplitude partial
eclipses and a non-negligible scatter of the data) does not allow for
a unique light-curve solution. Nevertheless, we show that the
assumption of normal primary-component mass and radius corresponding
to the O9.5 II classification (25M☉, 16-17R☉) leads to
consistent parameters for the system.
Description:
"Table1" contains all known radial velocities measured for δ Ori
"Table2" contains all known photometry of δ Ori.
Objects:
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RA (2000) DE Designation(s)
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05 32 00.40 -00 17 56.7 delta Ori = HD 36486
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1a.dat 32 824 RV measurements, third component not considered
table1g.dat 32 82 RV measurements by Gaussians with third component
tablea1.dat 113 16 Journal of available RV observations
table2a.dat 29 459 Photometry by Stebbins (1915ApJ....42..133S 1915ApJ....42..133S),
Storer (1930PASP...42..291S 1930PASP...42..291S),
Worley (1955PASP...67..330W 1955PASP...67..330W) and
Koch & Hrivnak (1981ApJ...248..249K 1981ApJ...248..249K),
table24.dat 70 5 Photometry of Johnson et al. (1966, CoLPL, 4, 99)
green and blue
table27.dat 38 89 HIPPARCOS photometry, Perryman et al. (1997, I/239)
table28.dat 61 149 This paper, δ Ori UBV photometry made at Hvar
table2e.dat 61 21 This paper, ε Ori UBV photometry made at Hvar
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table1a.dat table1g.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
15- 21 F7.2 km/s RV Radial velocity
23- 27 F5.3 --- Weight Weight of the data point
29- 30 I2 --- Source [1/16] Source, in tablea1.dat file
32 I1 --- code [1] "1" means primary component
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Source [1/16] Source number
4- 10 F7.1 d HJD1 Time interval, HJD-2400000
11 A1 --- --- [-]
12- 18 F7.1 d HJD2 Time interval, HJD-2400000
20- 22 I3 --- NRV Number of RV measurements
24- 69 A46 --- Tel Telescope and instrument
71-113 A43 --- Ref Reference
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Byte-by-byte Description of file: table2a.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 18 F5.3 mag mag Magnitude
20- 24 F5.3 --- Weight Weight of the data point
26- 27 I2 --- Source [1/10] Source (1)
29 I1 --- Band [3/4] 3: V or green magnitude,
4: blue magnitude
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Note (1): Source as follows:
1 = Stebbins (1915ApJ....42..133S 1915ApJ....42..133S)
2 = Storer (1930PASP...42..291S 1930PASP...42..291S)
3 = Worley (1955PASP...67..330W 1955PASP...67..330W)
9 = Koch & Hrivnak (1981ApJ...248..249K 1981ApJ...248..249K), green
10 = Koch & Hrivnak (1981ApJ...248..249K 1981ApJ...248..249K), blue
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Byte-by-byte Description of file: table24.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 18 F5.3 mag Vmag V magnitude
20- 25 F6.3 mag B-V B-V colour index
27- 32 F6.3 mag U-B U-B colour index
34- 39 F6.3 mag V-R V-R colour index
41- 46 F6.3 mag R-I R-I colour index
48- 52 I5 --- Weights Weights for UBVRI bands
54- 57 F4.2 --- X Air mass
59- 70 F12.4 d GJD Geocentric Julian date
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Byte-by-byte Description of file: table27.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 19 F6.4 mag Hp HIP magnitude
21- 25 F5.3 mag V(Hp) V magnitude transformed from HIP
27- 30 F4.2 --- Weight Weight of the data point
32- 36 F5.3 mag e_Hp rms uncertainty on Hp
38 I1 --- Flag [0/1] Flag
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Byte-by-byte Description of file: table28.dat table2e.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 18 F5.3 mag Vmag V magnitude
20- 24 F5.3 mag Bmag B magnitude
26- 30 F5.3 mag Umag U magnitude
32- 37 F6.3 mag B-V B-V colour index
39- 44 F6.3 mag U-B U-B colour index
46- 48 F3.1 --- Weight Weight of the data point
50- 54 F5.3 --- X Air mass
56- 61 F6.3 --- dX Difference of air mass "var minus comp"
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Acknowledgements:
Pavel Mayer, mayer(at)cesnet.cz
(End) Patricia Vannier [CDS] 19-Jul-2010