J/A+A/644/A49 Gaia18aen light and velocity curves (Merc+, 2020)
Gaia18aen: First symbiotic star discovered by Gaia.
Merc J., Mikolajewska J., Gromadzki M., Galan C., Ilkiewicz K., Skowron J.,
Wyrzykowski L., Hodgkin S.T., Rybicki K.A., Zielinski P., Kruszynska K.,
Godunova V., Simon A., Reshetnyk V., Lewis F., Kolb U., Morrell M.,
Norton A.J., Awiphan S., Poshyachinda S., Reichart D.E., Greet M.,
Kolgjini J.
<Astron. Astrophys. 644, A49 (2020)>
=2020A&A...644A..49M 2020A&A...644A..49M (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, cataclysmic ; Photometry ; Optical ; Radial velocities ;
Spectroscopy
Keywords: binaries: symbiotic - techniques: photometric -
techniques: spectroscopic - stars: individual: Gaia18aen
Abstract:
Besides the astrometric mission of the Gaia satellite, its repeated
and high-precision measurements also serve as an all-sky photometric
transient survey. The sudden brightenings of the sources are published
as Gaia Photometric Science Alerts and are made publicly available,
allowing the community to photometrically and spectroscopically follow
up on the object.
The goal of this paper is to analyze the nature and derive the basic
parameters of Gaia18aen, a transient detected at the beginning of
2018. This object coincides with the position of the emission-line
star WRAY 15-136. The brightening was classified as a "nova?" on the
basis of a subsequent spectroscopic observation.
We analyzed two spectra of Gaia18aen and collected the available
photometry of the object covering the brightenings in 2018 and also
the preceding and following periods of quiescence. Based on this
observational data, we derived the parameters of Gaia18aen and
discussed the nature of the object.
Gaia18aen is the first symbiotic star discovered by Gaia satellite.
The system is an S-type symbiotic star and consists of an M giant of a
slightly super-solar metallicity, where Teff∼3500K, a radius of
∼230R☉, and a high luminosity L∼7400L☉. The hot component
is a hot white dwarf. We tentatively determined the orbital period of
the system 487d. The main outburst of Gaia18aen in 2018 was
accompanied by a decrease in the temperature of the hot component. The
first phase of the outburst was characterized by the high luminosity
L∼27000L☉, which remained constant for about three weeks after
the optical maximum, later followed by the gradual decline of
luminosity and increase of temperature. Several re-brightenings have
been detected on the timescales of hundreds of days.
Description:
Gaia18aen was classified as the first symbiotic star discovered by the
Gaia satellite. We tabulate all the collected photometric observations
of Gaia18aen and positions, radial velocities and fluxes of identified
emission lines in the VLT/X-Shooter spectrum of Gaia18aen obtained on
March 22, 2018.
Objects:
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RA (2000) DE Designation(s)
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08 02 52.06 -30 18 37.2 Gaia18aen = WRAY 15-136
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 56 180 Positions, radial velocities, and fluxes of
identified emission lines in the VLT/X-Shooter
spectrum of Gaia18aen obtained on
March 22, 2018.
tablea1.dat 49 5846 Photometrical observations of Gaia18aen
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 F8.2 0.1nm lambda Measured wavelength of line in the spectrum
10- 24 A15 --- Line Identification of the line
25- 40 A16 0.1nm lambdaRef Reference wavelength of the line
42- 47 F6.1 10-17W/m2 Flux ? Measured flux in the line
(in 10-14erg/cm2/s) (1)
48 A1 --- n_Flux [s] s for saturated
52- 56 F5.1 km/s RV Radial velocity of the line,
heliocentric velocity corrected
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Note (1): De-redenned fluxes were calculated assuming E(B-V)=1.2, RV=3.1 and
extinction law of Cardelli et al. (1989ApJ...345..245C 1989ApJ...345..245C).
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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- 9 F9.3 d JD Date of observation (JD-240000)
11- 16 F6.3 mag mag Magnitude in Filter
18- 22 F5.3 mag e_mag ? Magnitude error in Filter
24 A1 --- Filter [G BVI co gri] Filter, in which the particular
observation was obtained
26- 49 A24 --- Source Source of the data (1)
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Note (1): Source of the data are:
ASAS-SN (Vg filters)
ATLAS (co filters)
Bochum (ri filters)
GAIA (G filter)
LCOGT 0.4m (Vri filters)
OGLE (VI filters)
PIRATE Robotic Telescope (RVrg filters)
PROMPT 0.6m (RVri filters)
Terskol-2 (BVri filters)
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Acknowledgements:
Jaroslav Merc, jaroslav.merc(at)gmail.com
(End) Patricia Vannier [CDS] 09-Nov-2020