Comprehensive study of a neglected contact binary TYC 5532-1333-1

2020 ◽  
Vol 493 (2) ◽  
pp. 1565-1573
Author(s):  
S P Devarapalli ◽  
R Jagirdar ◽  
R M Prasad ◽  
V S Thomas ◽  
S A Ahmed ◽  
...  
Keyword(s):  
Orbital Period ◽  
Period Variation ◽  
Third Body ◽  
Mutual Correlation ◽  
V Band ◽  
Angular Momentum Loss ◽  
Contact Binary ◽  
First Time ◽  
Comprehensive Study

ABSTRACT A comprehensive photometric and spectroscopic analysis of the variable TYC 5532-1333-1 (TYC) along with an investigation of its orbital period variation is presented for the first time. The B- and V-band photometric study indicates that TYC is an intermediate contact binary with degree of contact and mass ratio of 34 per cent and ∼0.24, respectively. The derived equivalent widths from the spectroscopic study of Hα and   Na-I lines reveal phase-dependent variation and mutual correlation. Using the available times of minimum light, an investigation of orbital period variation shows a long-term decrease at a rate of 3.98 × 10 −6 d yr−1. Expected causes for such decline in the orbital period could be angular momentum loss and a quasi-sinusoidal variation due to light-time effect probably caused by a third-body companion. The minimum mass of the third body (M3) was derived to be $0.65 \, \mathrm{M}_{\odot }$. Our presented study is an attempt to evaluate and understand the evolutionary state of above-mentioned neglected contact binary.

scholarly journals YZ Phoenicis: a very short period K-type contact binary with variation of the O’Connell effect and orbital period change

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Thawicharat Sarotsakulchai ◽  
Sheng-Bang Qian ◽  
Boonrucksar Soonthornthum ◽  
Xiao Zhou ◽  
Jia Zhang ◽  
...  
Keyword(s):  
Orbital Period ◽  
Hot Spot ◽  
Period Change ◽  
Third Body ◽  
Normal Contact ◽  
Short Period ◽  
Massive Component ◽  
Contact Binary ◽  
Period Decrease

Abstract YZ Phe is a very short-period contact binary (Sp. = K2 V) with an orbital period of 0.2347 d near the short period limit (0.22 d). We present the complete light curves which photometric data were obtained from the 60 cm telescope of PROMPT-8 at CTIO in Chile during 2016 June to October and 2017 August. The photometric solutions were determined by using the Wilson & Devinney code and the results reveal that YZ Phe is a W-subtype shallow contact binary ($f\sim 10\,$, q = 2.635, or 1/q = 0.379 for W subtype) with rotational motion of a large hot spot on the more massive component, showing a strong O’Connell effect with variation of maxima in photometric time series at period of 4.20 yr and stellar cycle at period of 1.28 yr. By compiling all available eclipse times, the result shows a long-term period decrease at a rate of dP/dt = −2.64(±0.02) × 10−8 d yr−1, superimposed on a cyclic variation (A3 = 0.0081 d and P3 = 40.76 yr). This variation cannot be explained by the Applegate mechanism. Thus, the cyclic change may be interpreted as the light-travel time effect via the presence of a cool third body. Based on photometric solutions, the third light was detected as $2\,$ of the total light in V and I bands. These results support the existence of a third body. The long-term period decrease can be explained by mass transfer from the more massive component ($M_2 \sim 0.74\, M_{\odot }$) to the less massive one ($M_1 \sim 0.28\, M_{\odot }$) or plus angular momentum loss (AML) via magnetic braking. With 1/q < 0.4 and long-term period decrease, all factors suggest that YZ Phe is on the AML-controlled state and its fill-out factor will increase, as well as the system evolving into a deeper normal contact binary.

scholarly journals CCD Observations and Analysis of the W UMA Type Binary SS Arietis

1998 ◽  
Vol 11 (1) ◽  
pp. 382-382
Author(s):  
Wonyong Han ◽  
Chun-Hwey Kim ◽  
Jae Woo Lee ◽  
Ho-Il Kim ◽  
Woo-Baik Lee
Keyword(s):  
Period Change ◽  
Light Curves ◽  
Period Variation ◽  
Light Elements ◽  
Astronomy Observatory ◽  
Third Body ◽  
Convective Envelope ◽  
Ccd Observations ◽  
The Times

The BVR CCD observations of W UMa-type eclipsing binary SS Arietis were made for ten nights from November 1996 to December 1996 at the Sobaeksan Astronomy Observatory. From the observed light curves, nine new times of minimum lights were derived from the Kwee and van Woerden’s method. Improved light elements for this system were determined from these minimum lights with all the published minima. The analysis of the times of minima of SS Ari confirms that the orbital period of SS Ari has been suffering from a sinusoidal variation as the suggestions of other previous investigators (Kaluzny & Pojmanski 1984, Demircan & Selam 1993). The calculation shows that the cyclic period change has a period of about 56.3yrs with an amplitude of about 0.d052. The period variation has been discussed in terms of two potential mechanisms: 1) the light-time effect due to a hypothetical third body and 2) deformations in the convective envelope of a magnetically active component. The BVR light curves of SS Ari observed for about one month showed the existence of cycle to cycle light variations. Long-term light changes of SS Ari are discussed in terms of the period variation of the binary system.

scholarly journals Long-term starspot evolution, activity cycle, and orbital period variation of V711 Tauri (HR 1099)

2006 ◽  
Vol 455 (2) ◽  
pp. 595-606 ◽  
Author(s):  
A. F. Lanza ◽  
N. Piluso ◽  
M. Rodonò ◽  
S. Messina ◽  
G. Cutispoto
Keyword(s):  
Orbital Period ◽  
Activity Cycle ◽  
Period Variation

scholarly journals The active RS CVn-type system SZ Pictoris

2019 ◽  
Vol 490 (4) ◽  
pp. 5832-5838
Author(s):  
C I Martínez ◽  
J F González ◽  
A Buccino ◽  
R Ibañez Bustos ◽  
P J D Mauas
Keyword(s):  
Orbital Period ◽  
Type System ◽  
Short Term ◽  
Cyclic Activity ◽  
Similar Time ◽  
Orbital Parameters ◽  
Secondary Star ◽  
V Band ◽  
Composite Spectra

ABSTRACT We study the short-term variability and long-term variability of the spectroscopic binary SZ Pictoris, a southern RS CVn-type system. We used mid-resolution Echelle spectra obtained at Complejo Astronómico El Leoncito spanning 18 yr, and the photometric data from the All Sky Automated Survey data base (V band) and from the Optical Robotic Observatory (BVRI bands) for similar time lapses. We separated the composite spectra into those corresponding to both components, and we were able to determine accurate orbital parameters, in particular an orbital period of 4.95 d. We also observed a photometric modulation with half the orbital period, due to the ellipticity of the stars. We also found cyclic activity with a period of ∼2030 d, both in the photometry and in the Ca ii flux of the secondary star of the system.

scholarly journals Long-term starspot evolution, activity cycle and orbital period variation of SZ Piscium

2001 ◽  
Vol 376 (3) ◽  
pp. 1011-1030 ◽  
Author(s):  
A. F. Lanza ◽  
M. Rodonò ◽  
L. Mazzola ◽  
S. Messina
Keyword(s):  
Orbital Period ◽  
Activity Cycle ◽  
Period Variation

scholarly journals Secular period decreasing of 17 detached chromospherically active binaries

2008 ◽  
Vol 4 (S252) ◽  
pp. 437-438
Author(s):  
C. Q. Luo ◽  
Y. P. Luo ◽  
X. B. Zhang ◽  
L. C. Deng ◽  
Z. Q. Luo ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Period ◽  
Close Binaries ◽  
Momentum Loss ◽  
System A ◽  
Angular Momentum Loss ◽  
Theoretical Predictions

AbstractThe long-term orbital period changes of detached chromospheric active binaries were surveyed. 17 of such systems are found to be undergoing secular period decreasing with the rates (dP/dt) of −3.05 × 10−9 to −3.77 × 10−5 days per year. The longer the orbital period, the more rapidly the period decreases. Following Stepien (1995), the period decreasing rate due to the angular momentum loss (AML) caused by magnetic wind is computed for each system. A comparison shows that the observed dP/dt's are obviously higher than that of the theoretical predictions by 1-3 orders of magnitude. It suggests that the magnetic wind is not likely the determinant mechanism driving the AML in close binaries.

scholarly journals Long-term starspot evolution, activity cycle and orbital period variation of RT Lacertae

2002 ◽  
Vol 386 (2) ◽  
pp. 583-605 ◽  
Author(s):  
A. F. Lanza ◽  
S. Catalano ◽  
M. Rodonò ◽  
C. İbanoǧlu ◽  
S. Evren ◽  
...  
Keyword(s):  
Orbital Period ◽  
Activity Cycle ◽  
Period Variation

scholarly journals Evidence of Angular Momentum Loss in the Eclipsing Binary VW Cephei

1998 ◽  
Vol 11 (1) ◽  
pp. 350-350
Author(s):  
M.J. Devita ◽  
D.H. Bradstreet ◽  
E.F. Guinan ◽  
Z. Glownia
Keyword(s):  
Angular Momentum ◽  
Third Body ◽  
Orbital Parameters ◽  
The Third ◽  
The Past ◽  
Momentum Loss ◽  
Steady Decrease ◽  
Short Period ◽  
Angular Momentum Loss

VW Cep is one of the brightest and longest observed short-period (P = 6.67 hours) W UMa type binaries. It consists of a G5V and K0V components in contact with their Roche surfaces. We investigated complex period changes based upon eclipse timings from the past 70 years. In addition to the well-known 30 year light time effect due to the presence of a third star in the system, we find evidence for a long term decrease in the orbital period of dP/dt = −0.02 sec/yr. This decrease in period could arise from angular momentum loss from the binary or mass exchange between components. From these timings we have refined the properties of the tertiary component and redetermined its mass and orbital parameters. After correcting the O-C’s for the third body and the steady decrease in Keplerian period, we uncovered small systematic deviations in the residual O-C’s. We are studying these second order period variations, possibly arising from mass loss in winds and/or mass flow between components, to determine if they correlate with known cycles of spot and surface activity.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

An Evaluation of Provincial Macroeconomic Performance in Vietnam

2017 ◽  
pp. 34-47
Author(s):  
Hoi Le Quoc ◽  
Nam Pham Xuan ◽  
Tuan Nguyen Anh
Keyword(s):  
Development Strategy ◽  
Institutional Transformation ◽  
Economic Indicators ◽  
Macroeconomic Performance ◽  
Economic Development Strategy ◽  
Socio Economic Development ◽  
The Cost ◽  
Development Objectives ◽  
First Time

The study was targeted at developing a methodology for constructing a macroeconomic performance index at a provincial level for the first time in Vietnam based on 4 groups of measurements: (i) Economic indicators; (ii) oriented economic indicators; (iii) socio-economic indicators; and (iv) economic - social – institutional indicators. Applying the methodology to the 2011 - 2015 empirical data of all provinces in Vietnam, the research shows that the socio-economic development strategy implemented by those provinces did not provide balanced outcomes between growth and social objectives, sustainability and inclusiveness. Many provinces focused on economic growth at the cost of structural change, equality and institutional transformation. In contrast, many provinces were successful in improving equality but not growth. Those facts threaten the long-term development objectives of the provinces.

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