Orbital period correction and light curve modeling of the W-subtype shallow contact binary OW Leo

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

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RSCVn Stars in the Southern Hemisphere

International Astronomical Union Colloquium ◽

10.1017/s0252921100073644 ◽

1979 ◽

Vol 46 ◽

pp. 371-384 ◽

Cited By ~ 3

Author(s):

J.B. Hearnshaw

Keyword(s):

Light Curve ◽

Southern Hemisphere ◽

Orbital Period ◽

Binary Stars ◽

Small Amplitude ◽

Light Variation ◽

Orbital Phase

RSCVn stars are fully detached binary stars which show intrinsic small amplitude (up to 0.3 amplitude peak-to-peak) light variations, as well as, in most of the known cases, eclipses. The spectra are F to G, IV to V for the hotter component and usually KOIV for the cooler. They are also characterised by abnormally strong H and K emission from the cooler star, or, occasionally, from both components. The orbital and light curve periods are in the range 1 day to 2 weeks. An interesting feature is the migration of the light variations to earlier orbital phase, as the light variation period is shorter than the orbital period by a few parts in 10+4to a few parts in 10+3.

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Light curve analysis of the late type binary V523 Cassiopeiae

Serbian Astronomical Journal ◽

10.2298/saj0978045l ◽

2009 ◽

pp. 45-48 ◽

Cited By ~ 4

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.

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

The Astronomical Journal ◽

10.1086/509604 ◽

2006 ◽

Vol 133 (1) ◽

pp. 255-260 ◽

Cited By ~ 3

Author(s):

Wenxian Lu ◽

Bruce J. Hrivnak ◽

Bradley W. Rush

Keyword(s):

Light Curve ◽

Radial Velocity ◽

Contact Binary

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Fluorescence and Chromospheric Activity of V471 Tau

International Astronomical Union Colloquium ◽

10.1017/s0252921100001366 ◽

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.

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Superhump period of SDSS J214354.59+124457.8: First Z Cam star with superhumps in the standstill

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2247 ◽

2019 ◽

Vol 489 (1) ◽

pp. 1451-1462

Author(s):

Metin Altan ◽

Taichi Kato ◽

Ryoko Ishioka ◽

Linda Schmidtobreick ◽

Tolga Güver ◽

...

Keyword(s):

Light Curve ◽

Orbital Period ◽

Timing Analysis ◽

Periodic Signal ◽

Mass Ratio ◽

Short Intervals ◽

Upper Limit ◽

Term Variation ◽

Two Phases

Abstract The cataclysmic variable SDSS J214354.59+124457.8 (hereafter SDSS J214354) was observed photometrically on sixty one nights between 2012 July 28 and 2019 May 26. The long term variation of this object shows changes between two phases; a dwarf nova type and a novalike. This implies that the object belongs to the group of Z Cam type stars. The timing analysis of the light curve reveals a periodic signal at 0.13902(5) d, which we identify as the superhump period. However, the fractional superhump excess of 10 per cent longer than the orbital period is exceptionally large. We obtained a mass ratio of ∼0.4, which is above the accepted upper limit of q = 0.33 for the formation of superhumps. We suggest that the object contains a secondary with an evolved core. With an orbital period of 0.126 d, SDSS J214354 is situated at the upper border of the period gap. The long term light curve of SDSS J214354 is similar to those of Z Cam type stars which are characterized by recurring standstills, followed by short intervals with DN type outbursts. Therefore, we conclude that SDSS J214354 is a new member of the Z Cam type stars.

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Epsilon Aurigae: A Supergiant and a Super Disk

International Astronomical Union Colloquium ◽

10.1017/s0252921100087947 ◽

1989 ◽

Vol 107 ◽

pp. 336-336

Author(s):

Sean Carroll ◽

Edward Guinan ◽

George McCook ◽

Robert Donahue

Keyword(s):

Light Curve ◽

Orbital Period ◽

Instability Strip ◽

Eclipsing Binary ◽

Characteristic Period ◽

Photoelectric Observations ◽

Low Amplitude ◽

Epsilon Aurigae ◽

Villanova University

The eclipsing binary Epsilon Aurigae consists of an F0 supergiant and a cool, mysterious eclipsing companion with an orbital period of 27.1 years. The light curve of this system reveals two sources of variability: the eclipses themselves and the intrinsic variation of the supergiant. Multifilter photoelectric observations were made with the 38 cm reflector at the Villanova University Observatory. These data were analyzed along with other sources to reveal the nature of the components of the Epsilon Aurigae system. The system undergoes low-amplitude semi-regular light variations with a characteristic period of 110 days and perhaps a longer period of 500-600 days. The proximity of Epsilon Aur to the Cepheid instability strip on the H-R diagram suggests that the pulsation mechanism for this star may be similar to that of Cepheids.

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