Light-Curve and Radial Velocity Study of the Contact Binary BD +42 2782

2006 ◽  
Vol 133 (1) ◽  
pp. 255-260 ◽  
Author(s):  
Wenxian Lu ◽  
Bruce J. Hrivnak ◽  
Bradley W. Rush
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Contact Binary

scholarly journals The Contact Binary H235 in the Open Cluster NGC 752

1992 ◽  
Vol 151 ◽  
pp. 487-490
Author(s):  
E. F. Milone ◽  
C. R. Stagg ◽  
B.J.A. Sugars ◽  
J.R. Mcvean ◽  
S. J. Schiller ◽  
...  
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Open Cluster ◽  
Type System ◽  
Contact Parameter ◽  
Contact Binary ◽  
Rule Out

Photoelectric BVRI light and radial velocity curves of the 0.41d period eclipsing variable have been analyzed with a new, simplex-enhanced version of the Wilson-Devinney light curve program, and used to explore detached, semi-detached, and contact solutions. The system is best modeled as a W-type W UMa system, with contact parameter, f = 0.44, although at time of writing, we cannot rule out the possibility of an A-type system.

A Radial Velocity and Light Curve Study of Pulsations and Binarity in Proto-Planetary Nebulae

2015 ◽  
Vol 71-72 ◽  
pp. 127-128
Author(s):  
B.J. Hrivnak ◽  
W. Lu ◽  
G. Van de Steene ◽  
H. Van Winckel ◽  
J. Sperauskas ◽  
...  
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Planetary Nebulae

scholarly journals Light curve analysis of the late type binary V523 Cassiopeiae

2009 ◽  
pp. 45-48 ◽  
Author(s):  
O. Latkovic ◽  
M. Zboril ◽  
G. Djurasevic
Keyword(s):  
Light Curve ◽  
Monitoring Program ◽  
Neck Region ◽  
Bright Spot ◽  
Late Type ◽  
Light Curve Analysis ◽  
Type Contact ◽  
Contact Binary ◽  
Previous Solution

We present the analysis of V and R light curves of the late type contact binary V523 Cas for the season of 2006. These observations make part of the monitoring program aimed at studying the long-term light curve variability in this system. Our results confirm that the system is in an over contact configuration, and include a bright spot in the neck region of the cooler and larger primary. We compare these results with the previous solution, obtained for the season 2005 dataset and discuss the differences.

scholarly journals Spectroscopic Orbit of the Eclipsing Binary BD +52°2009

1999 ◽  
Vol 170 ◽  
pp. 325-330
Author(s):  
B. Khalesseh
Keyword(s):  
Correlation Function ◽  
Light Curve ◽  
Radial Velocity ◽  
Physical Model ◽  
Cross Correlation ◽  
Cross Correlation Function ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Velocity Measurements ◽  
Eclipsing Binary

AbstractNew radial velocity measurements of the Algol-type eclipsing binary BD +52 °2009, based on Reticon observations, are presented. The velocity measures are based on fitting theoretical profiles, generated by a physical model of the binary, to the observed cross-correlation function (ccf). Such profiles match this function very well, much better in fact than Gaussian profiles, which are generally used. Measuring the ccf’s with Gaussian profiles yields the following results: mp sin3i = 2.55 ± 0.05m⊙, ms sin3i = 1.14 ± 0.03m⊙, (ap + as) sin i = 7.34 ± 0.05R⊙, and mp/ms = 2.23 ± 0.05. However, measuring the ccf’s with theoretical profiles yields a mass ratio of 2.33 and following results: mp sin3i = 2.84 ± 0.05m⊙, ms sin3i = 1.22 ± 0.03m⊙, (ap + as) sin i = 7.56 ± 0.05R⊙. The system has a semi-detached configuration. By combining the solution of a previously published light curve with the spectroscopic orbit, one can obtain the following physical parameters: mp = 2.99m⊙, ms3 = 1.28m⊙, < Tp >= 9600K, < Ts >= 5400K, < Rp >= 2.35R⊙, < Rs >= 2.12R⊙. The system consists of an A0 primary and a G2 secondary.

scholarly journals Fluorescence and Chromospheric Activity of V471 Tau

2002 ◽  
Vol 187 ◽  
pp. 167-172
Author(s):  
T.R. Vaccaro ◽  
R.E. Wilson
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Star ◽  
Star Model ◽  
Orbital Inclination ◽  
Orbital Parameters ◽  
Maximum Emission ◽  
Chromospheric Activity

AbstractThe red dwarf + white dwarf eclipsing binary V471 Tau shows a variable Hα feature that varies from absorption during eclipse to maximum emission during white dwarf transit. In 1998 we obtained simultaneous BVRI photometry and Hα spectroscopy, with thorough phase coverage of the 12.5 hour orbital period. A binary star model was used with our light curve, radial velocity, and Hα data to refine stellar and orbital parameters. Combined absorption-emission profiles were generated by the model and fit to the observations, yielding a red star radius of 0.94R⊙. Orbital inclination 78° is required with this size and other known parameters. The model includes three spots 1,000 K cooler than the surrounding photosphere. The variable Hα profile was modeled as a chromospheric fluorescing region (essentially on the surface of the red star) centered at the substellar point. Additional emission seen outside our modeled profiles may be large co-rotating prominences that complicate the picture.

scholarly journals The Long-term Variation in the RV Tauri Star U Mon

1995 ◽  
Vol 155 ◽  
pp. 409-410 ◽  
Author(s):  
Karen R. Pollard ◽  
P. L. Cottrell
Keyword(s):  
High Resolution ◽  
Light Curve ◽  
Radial Velocity ◽  
Tauri Star ◽  
Short Term ◽  
Instability Strip ◽  
Term Variation ◽  
Velocity Variations

The RV Tauri stars are semiregular pulsating variables located in the brightest part of the Cepheid II instability strip. They have a characteristic light curve of alternating deep and shallow minima. A subset of the RV Tauri stars (the RVb subclass) exhibit long-term (500 to 2600 day) light and radial velocity variations. Although it is well established that the short-term variations are due to pulsations, the long-term behaviour is not well understood.BVRI photometry and high-resolution spectra of U Mon (the brightest member of the RVb subclass) were obtained at the Mt John University Observatory (MJUO) between 1990 Aug and 1994 May. The light and colour curves obtained clearly show the long-term variation in U Mon (Fig. 1(a) and (b)). The reddest colours occur slightly later than the long-term minimum in the light curve. The short-term light and colour variations are ‘damped’ at the long-term minimum.

scholarly journals Phase connected X-ray light curve and He II radial velocity measurements of NGC 300 X-1

2018 ◽  
Vol 14 (S346) ◽  
pp. 187-192
Author(s):  
S. Carpano ◽  
F. Haberl ◽  
P. Crowther ◽  
A. Pollock
Keyword(s):  
Black Hole ◽  
Light Curve ◽  
Radial Velocity ◽  
Orbital Period ◽  
High Mass ◽  
Velocity Measurements ◽  
X Ray ◽  
Black Hole Radiation ◽  
Ic 10 ◽  
Binary Evolution

Abstract. NGC 300 X-1 and IC 10 X-1 are currently the only two robust extragalactic candidates for being Wolf-Rayet/black hole X-ray binaries, the Galactic analogue being Cyg X-3. These systems are believed to be a late product of high-mass X-ray binary evolution and direct progenitors of black hole mergers. From the analysis of Swift data, the orbital period of NGC 300 X-1 was found to be 32.8 h. We here merge the full set of existing data of NGC 300 X-1, using XMM-Newton, Chandra and Swift observations to derive a more precise value of the orbital period of 32.7932 ± 0.0029 h above a confidence level of 99.99%. This allows us to phase connect the X-ray light curve of the source with radial velocity measurements of He II lines performed in 2010. We show that, as for IC 10 X-1 and Cyg X-3, the X-ray eclipse corresponds to maximum of the blueshift of the He II lines, instead of the expected zero velocity. This indicates that for NGC 300 X-1 as well, the wind of the WR star is completely ionised by the black hole radiation and that the emission lines come from the region of the WR star that is in the shadow. We also present for the first time the light curve of two recent very long XMM-Newton observations of the source, performed on the 16th to 20th of December 2016.

scholarly journals Observability of the General Relativistic Precession of Periastra in Exoplanets

2008 ◽  
Vol 4 (S253) ◽  
pp. 492-495
Author(s):  
Andrés Jordán ◽  
Gáspár Á. Bakos
Keyword(s):  
General Relativity ◽  
Light Curve ◽  
Radial Velocity ◽  
Time Difference ◽  
Precession Rate ◽  
Secular Variations ◽  
General Relativistic ◽  
Tidal Deformations

AbstractThe general relativistic precession rate of periastra in close-in exoplanets can be orders of magnitude larger than the magnitude of the same effect for Mercury. The realization that some of the close-in exoplanets have significant eccentricities raises the possibility that this precession might be detectable. We explore here the observability of the periastra precession using radial velocity and transit light curve observations. Our analysis is independent of the source of precession, which can also have significant contributions due to additional planets and tidal deformations. We find that precession of the periastra of the magnitude expected from general relativity can be detectable in timescales of ≲10 years with current observational capabilities by measuring the change in the primary transit duration or in the time difference between primary and secondary transits. Radial velocity curves alone would be able to detect this precession for super-massive, close-in exoplanets orbiting inactive stars if they have ~100 datapoints at each of two epochs separated by ~20 years. The contribution to the precession by tidal deformations may dominate the total precession in cases where the relativistic precession is detectable. Studies of transit durations withKeplermight need to take into account effects arising from the general relativistic and tidal induced precession of periastra for systems containing close-in, eccentric exoplanets. Such studies may be able to detect additional planets with masses comparable to that of Earth by detecting secular variations in the transit duration induced by the changing longitude of periastron.

scholarly journals UBVRI Photometric Analysis of the Solar-Type Eclipsing Binary TYC 3034-299-1

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Ronald G. Samec ◽  
Adam Jaso ◽  
Jesse White ◽  
Danny R. Faulkner ◽  
Nicholas Blum ◽  
...  
Keyword(s):  
Light Curve ◽  
Massive Star ◽  
Light Curves ◽  
Dark Spot ◽  
Mass Ratio ◽  
Photometric Analysis ◽  
Contact Binary ◽  
Solar Type ◽  
Curve Solution ◽  
Light Curve Solution

TYC 3034-0299-1 (CVn) is a magnetically active, contact binary, ROTSE variable. UBVRcIc light curves are presented along with a period study and a simultaneous UBVRI light curve solution. Our light curves show eclipse amplitudes of 0.72 and 0.62 mags (V) in the primary and secondary eclipses. Modeled results include a dark spot region, found at longitude 51°, a 24% Roche lobe fill-out, and a mass ratio of 0.48. A total eclipse is found to occur in the secondary eclipse making TYC 3034-0299-1 a W-type (less massive star is hotter) W UMa variable.

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