J/A+A/699/A321 V1624 Cyg UBV and RV curves (Harmanec+, 2025)
Spectroscopic orbit and variability of the Be star V1624 Cyg = 28 Cyg.
Harmanec P., Yang S., Koubsky P., Labadie-Bartz J., Dolezal P.,
Ranguin S., Bozic H., Svrckova J., Zummer M., Zasche P., Ak H.
<Astron. Astrophys. 699, A321 (2025)>
=2025A&A...699A.321H 2025A&A...699A.321H (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Stars, Be ; Photometry, UBV ;
Radial velocities
Keywords: binaries: spectroscopic - stars: emission-line, Be -
stars: fundamental parameters - Stars: individual: V1624 Cyg
Abstract:
In recent years the idea, first formulated many decades ago, that the
Be phenomenon could be causally related to the duplicity of Be stars,
has been repeatedly reconsidered from various perspectives. It is
important, therefore, to have reliable information on Be stars, which
are confirmed members of binary systems. This study is devoted to
V1624 Cyg = 28 Cygni, which was recently identified as a binary with a
compact secondary. By measuring the radial velocities (RVs) of the
wings of the H alpha emission line and using archival data and
published RVs from the International Ultraviolet Explorer, we
demonstrate that the Be primary moves in the 359.26d orbit found
recently from interferometry. Our preliminary radial-velocity solution
leads to binary masses of 5.6, and 0.66 solar masses. Moreover, we
documented large and irregular spectral, brightness, and colour
changes over a time interval of several decades to show that the
object never completely lost its circumstellar matter.
Description:
Individual radial velocities of absorption and Balmer emission lines
for the data from the literature and from our new electronic spectra.
Different instruments used are identified by numerical codes defined
in Tables 1 and 2 of the paper.
Individual ground-based photometric observations of V1624 Cyg from
different observing stations. The observing stations are identified by
numerical codes defined in Table 5 of the paper.
Objects:
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RA (2000) DE Designation(s)
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20 09 25.61 +36 50 22.6 V1624 Cyg = * 28 Cyg
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 27 296 Absorption and emission-line radial velocities
from the literature
table4.dat 27 308 Absorption and emission-line radial velocities
from our electronic spectra
table6.dat 52 993 Inidividual UBV photometric observations
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian date (HJD-2400000)
12- 17 F6.2 km/s RVabs ?=- Individual radial velocities of
absorption lines
19- 24 F6.2 km/s RVem ?=- Individual radial velocities of
Balmer emission
26- 27 I2 --- Inst Numerical code of the spectrograph used
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian date (HJD-2400000)
12- 16 F5.3 mag Vmag ?=- Johnson V magnitude
18- 22 F5.3 mag Bmag ?=- Johnson B magnitude
24- 28 F5.3 mag Umag ?=- Johnson U magnitude
30- 35 F6.3 mag B-V ?=- Johnson B-V colour index
37- 42 F6.3 mag U-B ?=- Johnson U-B colour index
44- 49 I6 --- HDcomp ?=0 HD number of the comparison star used
51- 52 I2 --- Station Numerical code of the observing station
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Acknowledgements:
Petr Harmanec, Petr.Harmanec(at)matfyz.cuni.cz,
Astronomical institute, Charles University, Czech Republic
(End) P. Harmanec [Astron. Inst. Charles Univ], P. Vannier [CDS] 21-May-2025