J/A+A/670/A94 V4142 Sgr radial velocity curves (Rosales+, 2023)
V4142 Sgr: Double periodic variable with an accretor surrounded by the
accretion disk's atmosphere.
Rosales J.A., Mennickent R.E., Djurasevic G., Araya I., Cure M.,
Schleicher D.R.G., Petrovic J.
<Astron. Astrophys. 670, A94 (2023)>
=2023A&A...670A..94R 2023A&A...670A..94R (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Binaries, spectroscopic ; Stars, B-type ;
Radial velocities ; Optical
Keywords: binaries: eclipsing - binaries: spectroscopic - stars: early-type -
circumstellar matter - stars: fundamental parameters -
stars: mass-loss
Abstract:
A detailed study of the close interacting binary V4142 Sgr, based on
photometric and spectroscopic analyses, indicates that this system
belongs to the enigmatic class of Algol-like variables exhibiting a
long photometric cycle of an unknown nature.
By performing photometric data-mining and spectroscopic observations
covering the orbital cycle, we obtained the orbital parameters and the
stellar properties of the binary system, along with the physical
properties of the accretion disk located around the hot star. In
addition, we gained insights into the evolutive path of the system.
We modeled the light curve through an inverse method, using a
theoretical light curve of the binary system that considers the
light curve contribution of both stars and the accretion disk of the
hot star to obtain the fundamental parameters. To constrain the main
stellar parameters, the mass ratio was fixed in addition to the donor
temperature, using the obtained values from our spectroscopic
analysis, which includes deblending methods to isolate the spectral
lines of the stellar components. The system parameters were compared
with a grid of binary star evolutive models in order to gain insights
into the evolutionary history of the system.
The orbital period and the long cycle were re-calculated, with the
following result: 30.633±002days and 1201±14 days. The spectral
analysis reveals H double emission with a persistent V≤R asymmetry,
which is considered evidence of a possible wind emerging from the
hotspot region. In addition, a cold and evolved donor star of
Md=1.11±0.2M☉, Td=4500±125K and a Rd=19.4±0.2R☉ as
well as a rejuvenated B-dwarf companion of Mg=3.86±0.3 M☉,
Tg=14380±700K; and Rg=6.35±0.2R☉ were found. The gainer is
surrounded by a concave and geometrically thick disk, creating its own
atmosphere around the main component of a radial extension,
Rd=22.8±0.3R☉ , contributing 1:4 percent of the total
luminosity of the system at the V-band at orbital phase 0.25. The disk
is characterized by a hot-spot roughly placed where the stream hits
the disk and an additional bright-spot separated 102.5±0.04-degrees
along the disk edge rim in the direction of the orbital motion. The
system is seen under an inclination of 81.5±0.3° and at a
distance of dGaia=1140±35pc. Doppler maps of the emission lines
reveal sites of enhanced line emission in the second and third
velocity quadrants. The former would correspond to a hotspot and the
latter to a bright spot detected by the light curve analysis. We find
that the system comes from an initially shorter orbital period binary
that inverted its mass ratio due to mass exchange. A plausible model
scenario indicates that, at present, the K-type giant should have been
depleted of hydrogen in its core, while the companion would have
gained about 2M☉ through a process lasting about 2Myr.
Description:
A detailed study of the close interacting binary V4142 Sgr based on
photometric and spectroscopic analysis is presented. This system
belongs to the enigmatic class of Algol-like variables showing a
second photometric variability called long photometric cycle and of an
unknown nature. To investigate the orbital parameter of V4142 Sgr we
considered 806 better-quality data points in the V-band labeled as
A-type from the ASAS catalog and we rejected all outlier points and
157 data sets from ASAS-SN Variable Stars Database. In addition, to
investigate the fundamental properties of the DPV V4142 Sgr, a series
of 16 spectra with resolving power R∼27000 (fiber mode) was
collected with the CHIRON spectrograph mounted at the SMARTS 1.5-meter
telescope, located in Cerro Tololo Interamerican Observatory. The
covered spectral region is from 4500{angstrom} to 8500{angstrom} with
a mean signal-to-noise ratio of ∼92. The observations were conducted
during the maximum of the long cycle and cover relatively well the
orbital cycle
Objects:
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RA (2000) DE Designation(s)
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18 07 44.57 -28 24 04.2 V4142 Sgr = HD 317151
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 43 10 Summary of photometric data for V4142 Sgr
at different band passes
table2.dat 50 16 Summary of spectroscopic observation using
CHIRON spectrograph
table3.dat 33 11 Radial velocities of the gainer star and
their respective errors
table4.dat 33 16 Radial velocities of the donor star and
their respective errors
table6.dat 312 1 Fundamental parameters obtained by solving the
inverse problem for the Roche model with an
accretion disk around the more-massive (hotter)
gainer in the critical non-synchronous
rotation regime
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Table 5: Orbital parameters for the donor star of V4142 Sgr
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Parameter Best value Lower limit Upper limit
-------------------------------------------------------------
tau 302.332 302.189 302.474
e 0.000 0.000 0.017
omega (rad) 2.96196 2.93310 2.98810
Kd (km/s) 89.0 87.4 90.6
gamma (km/s) 0.2 -1.3 1.7
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 ---- Band Name of pass band
13- 19 F7.4 mag mag Magnitude in band
25- 30 F6.4 mag e_mag Associated error to magnitude in band
35- 43 F9.2 0.1nm lambdaEff Effective wavelength of the Band Pass
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "date" Date Date FITS file was generated in the
Universal Time (UT)
12- 15 I4 s ExpTime Requested exposure time
17- 32 F16.8 d HJD Heliocentric Julian Day
34- 39 F6.4 ---- phio Orbital phase of the system
41- 46 F6.4 ---- phil Long cycle phase of the system
48- 50 I3 ---- S/N Signal to noise
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Byte-by-byte Description of file: table3.dat table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 16 F16.8 d HJD Heliocentric Julian Day
18- 23 F6.4 ---- phio Orbital phase of the system
25- 29 F5.1 km/s RV Radial velocity of the system
31- 33 F3.1 km/s e_RV Associated error to the radial velocity
of the system
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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- 3 I3 ---- N Number of observations
5- 10 F6.4 ---- sum(O-C)2 Final sum of squares of residuals between
observed (LCO) and synthetic (LCC)
light-curves
12- 17 F6.4 ---- sigma-rms Root-mean-square of the residuals
19- 22 F4.1 deg i Orbit inclination
24- 26 F3.1 deg e_i Associated error for orbit inclination
28- 32 F5.3 ---- Fd Disk dimension factor (the ratio of the disk
radius to the critical Roche lobe radius
along y-axis)
34- 37 F4.2 ---- e_Fd Associated error for Disk dimension factor
39- 42 I4 K Td Disk-edge temperature
44- 46 I3 K e_Td Associated error for Disk-edge temperature
48- 52 F5.3 --- dea Disk thicknesses at the edge of the disk in
the units of the distance between the
components
54- 58 F5.3 --- e_dea Associated error for Disk thicknesses at the
edge of the disk
60- 64 F5.3 --- dca Disk thicknesses at the center of the disk
in the units of the distance between the
components
66- 70 F5.3 --- e_dca Associated error for Disk thicknesses at the
center of the disk
72- 75 F4.2 ---- aT Alpha disk temperature distribution
coefficient
77- 80 F4.2 ---- e_aT Associated error for Alpha disk temperature
distribution coefficient
82- 85 F4.1 ---- fh Non-synchronous rotation coefficient of the
more massive gainer (in the critical
non-synchronous rotation regime)
87- 89 F3.1 ---- e_fh Associated error for Non-synchronous
rotation coefficient
91- 95 F5.3 ---- Fh Filling factor for the critical
non-synchronous lobe of the hotter,
more-massive gainer
97-101 I5 K Th Temperature of the gainer star
103-105 I3 K e_Th Associated error for Temperature of the
gainer star
107-110 F4.2 ---- Ahs Hot spot temperature coefficients
112-115 F4.2 ---- e_Ahs Associated error for Hot spot temperature
coefficients
117-120 F4.1 deg thetahs Spot angular dimension
122-124 F3.1 deg e_thetahs Associated error for Spot angular dimension
126-130 F5.1 deg lambdahs Longitude of hot spot
132-134 F3.1 deg e_lambdahs Associated error for Longitude of hot spot
136-139 F4.1 deg thetarad Angle between the line perpendicular to the
local disk edge surface and the direction
of the hot-spot maximum radiation
141-143 F3.1 deg e_thetarad Associated error for Angle between the line
perpendicular to the local disk edge
surface and the direction of the hot-spot
maximum radiation
145-148 F4.2 ---- Abs bright spot temperature coefficient
150-153 F4.2 ---- e_Abs Associated error for bright spot temperature
coefficient
155-158 F4.1 deg thetabs Spot angular dimension
160-162 F3.1 deg e_thetabs Associated error for Spot angular dimension
164-168 F5.1 deg lambdabs Spot longitude dimension
170-172 F3.1 deg e_lambdabs Associated error for Spot longitude
dimension
174-179 F6.3 ---- Omegah Dimensionless surface potentials of the
hotter gainer
181-185 F5.3 ---- e_Omegah Associated error for Dimensionless surface
potentials of the hotter gainer
187-191 F5.3 ---- Omegac Dimensionless surface potentials of the
cooler donor
193-197 F5.3 ---- e_Omegac Associated error for Dimensionless surface
potentials of the cooler donor
199-202 F4.2 Msun Mh Stellar mass of the hotter gainer
204-207 F4.2 Msun e_Mh Associated error for Stellar mass of gainer
star
209-212 F4.2 Msun Mc Stellar mass of the cooler donor
214-217 F4.2 Msun e_Mc Associated error for Stellar mass of
the donor star
219-222 F4.2 Rsun Rh Stellar radius of the hotter gainer
224-227 F4.2 Rsun e_Rh Associated error for Stellar radius of
gainer star
229-232 F4.1 Rsun Rc Stellar radius of the cooler donor
234-236 F3.1 Rsun e_Rc Associated error for Stellar radius
of the donor star
238-241 F4.2 [cm/s2] loggh Logarithm (base 10) of hotter gainer
effective gravity
243-246 F4.2 [cm/s2] e_loggh Associated error for Logarithm (base 10) of
hotter gainer effective gravity
248-251 F4.2 [cm/s2] loggc Logarithm (base 10) of the cooler donor
effective gravity
253-256 F4.2 [cm/s2] e_loggc Associated error for Logarithm (base 10) of
the cooler donor effective gravity
258-262 F5.2 mag Mhbol Absolute stellar bolometric magnitude of
hotter gainer
264-267 F4.2 mag e_Mhbol Associated error for Absolute stellar
bolometric magnitude of hotter gainer
269-273 F5.2 mag Mcbol Absolute stellar bolometric magnitude of
cooler donor
275-278 F4.2 mag e_Mcbol Associated error for Absolute stellar
bolometric magnitude of cooler donor
280-283 F4.1 Rsun aorb Orbital semi-major axis
285-287 F3.1 Rsun e_aorb Associated error for Orbital semi-major axis
289-292 F4.1 Rsun Rd Disk radius in solar units
294-296 F3.1 Rsun e_Rd Associated error for Disk radius
298-300 F3.1 Rsun de Disk thicknesses its edge in solar units
302-304 F3.1 Rsun e_de Associated error for Disk thicknesses
its edge
306-308 F3.1 Rsun dc Disk thicknesses its center in solar units
310-312 F3.1 Rsun e_dc Associated error for Disk thicknesses
its center
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Acknowledgements:
Jaime Rosales Guzman, jrosales(at)astro-udec.cl
(End) Patricia Vannier [CDS] 31-Jan-2023