J/A+A/563/A120 Y Cyg light curves and time of minima (Harmanec+, 2014)
Revised physical elements of the astrophysically important O9.5+O9.5V eclipsing
binary system Y Cygni.
Harmanec P., Holmgren D.E., Wolf M., Bozic H., Guinan E.F., Kang Y.W.,
Mayer P., McCook G.P., Nemravova J., Yang S., Slechta M., Ruzdjak D.,
Sudar D., Svoboda P.
<Astron. Astrophys. 563, A120 (2014)>
=2014A&A...563A.120H 2014A&A...563A.120H
ADC_Keywords: Binaries, spectroscopic ; Photometry, UBVRI
Keywords: binaries: spectroscopic - stars: fundamental parameters -
stars: individual: Y Cyg - binaries: close
Abstract:
Rapid advancements in light-curve and radial-velocity curve modelling,
as well as improvements in the accuracy of observations, allow more
stringent tests of the theory of stellar evolution. Binaries with
rapid apsidal advance are particularly useful in this respect since
the internal structure of the stars can also be tested.
Thanks to its long and rich observational history and rapid apsidal
motion, the massive eclipsing binary Y Cyg represents one of the
cornerstones of critical tests of stellar evolutionary theory for
massive stars. Nevertheless, the determination of the basic physical
properties is less accurate than it could be given the existing number
of spectral and photometric observations. Our goal is to analyse all
these data simultaneously with the new dedicated series of our own
spectral and photometric observations from observatories widely
separated in longitude.
Description:
We obtained new series of UBV observations at three observatories
separated in local time to obtain complete light curves of Y Cyg for
its orbital period close to 3 days. This new photometry was reduced
and carefully transformed to the standard UBV system using the HEC22
program.
Objects:
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RA (2000) DE Designation(s)
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20 52 03.58 +34 39 27.5 Y Cyg = HD 198846 = BD+34 4184
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 26 5146 All 5146 individual photometric observations of Y Cyg
table5.dat 32 560 Observed primary and secondary minima of Y Cyg
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d RJD [20777/54406] Heliocentric Julian date
(HJD-2400000.0)
12- 16 F5.3 mag mag Observed magnitude of Y Cyg in Band
18- 21 F4.2 -- w_mag Weight of the data point
23- 24 I2 -- Dataset Number of dataset (1)
26 I1 -- Band [3/6] Observad band code (3 = V (or visual),
4 = B, 5 = U, 6 = R) (2)
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Note (1): Numerical codes identifying photometric observations from individual
stations (see Table 3 in the paper) and numbers of individual datasets:
----------------------------------------------------
Station V B U R Dugan vis.
No. code code code code code
----------------------------------------------------
- - - - - 20
74 - 21 -
76 2 22 -
71 3 23 43
42 5 25 45
75 6 26 -
72 7 27 47
70 - 28 -
94 9 - -
61 10 - -
77 11 - -
54 12 - -
----------------------------------------------------
01 13 33 53
16 14 34 54
78 15 35 55
02 16 36 - 76
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Note (2): Band code as follows:
3 = Dugan's visual and V-band observations
4 = B-band observations
5 = U-band observations
6 = R-band observations
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d RJD Heliocentric Julian date (HJD-2400000.0)
13- 18 F6.4 d rms Estimated error of the minimum time
20- 23 F4.1 --- w Weight of the minimum
25- 32 F8.1 --- Cycle Epoch of the minimum (1)
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Note (1): The secondary minima are identified by a fraction 0.5 in the
respective epochs.
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Acknowledgements:
Petr Harmanec, hec(at)sirrah.troja.mff.cuni.cz
(End) Patricia Vannier [CDS] 28-Jan-2014