scholarly journals New CCD Observations of Eclipsing Binary VW Cephei

1998 ◽  
Vol 11 (1) ◽  
pp. 394-394
Author(s):  
Adbdulrahman Ali S. Malawi
Keyword(s):  
Time Scale ◽  
Light Curves ◽  
Short Time Scale ◽  
Eclipsing Binary ◽  
Photometric Elements ◽  
Ccd Observations ◽  
Short Time

New CCD observations of the eclipsing binary VW Cephei were made on the 9th and 10th of October 1996 and on the 11th of Nov. 1996. The light curves and short time-scale variations are discussed. Photometric elements were determined from analyses of the light curves. These new solutions are also discussed.

scholarly journals Short time-scale fluctuations in the difference light curves of QSO 0957+561A,B: microlensing or noise?

2001 ◽  
Vol 322 (2) ◽  
pp. 397-410 ◽  
Author(s):  
R. Gil-Merino ◽  
L. J. Goicoechea ◽  
M. Serra-Ricart ◽  
A. Oscoz ◽  
D. Alcalde ◽  
...  
Keyword(s):  
Time Scale ◽  
Light Curves ◽  
Short Time Scale ◽  
The Difference ◽  
Short Time

scholarly journals Detection of small-size planetary candidates with CoRoT data

2010 ◽  
Vol 6 (S276) ◽  
pp. 523-524
Author(s):  
Aldo S. Bonomo ◽  
Pierre-Yves Chabaud ◽  
Magali Deleuil ◽  
Claire Moutou ◽  
Pascal Bordé
Keyword(s):  
Time Scale ◽  
Detection Threshold ◽  
Space Mission ◽  
Light Curves ◽  
Short Time Scale ◽  
Blind Test ◽  
Short Period ◽  
Short Time ◽  
Rocky Planets

AbstractWith the discovery of CoRoT-7b, the first transiting super-Earth, the CoRoT space mission has shown the capability to detect short-period rocky planets around solar-like stars. By performing a blind test with real CoRoT light curves, we want to establish the detection threshold of small-size planets in CoRoT data. We investigate the main obstacles to the detection of transiting super-Earths in CoRoT data, notably the presence of short-time scale variability and hot pixels.

scholarly journals Comparisons of MHD propeller model with observations of cataclysmic variable AE Aqr

2019 ◽  
Vol 487 (2) ◽  
pp. 1754-1763 ◽  
Author(s):  
A A Blinova ◽  
M M Romanova ◽  
G V Ustyugova ◽  
A V Koldoba ◽  
R V E Lovelace
Keyword(s):  
Magnetic Field ◽  
Time Scale ◽  
Accretion Rate ◽  
Light Curves ◽  
Short Time Scale ◽  
Mhd Simulations ◽  
Representative Model ◽  
Polar Type ◽  
Short Time ◽  
The Magnetic Field

ABSTRACT We have developed a numerical magnetohydrodynamic (MHD) model of the propeller candidate star AE Aqr using axisymmetric MHD simulations. We suggest that AE Aqr is an intermediate polar-type star, where the magnetic field is relatively weak and an accretion disc may form around the white dwarf. The star is in the propeller regime, and many of its observational properties are determined by the disc–magnetosphere interaction. Comparisons of the characteristics of the observed versus modelled AE Aqr star show that the model can explain many observational properties of AE Aqr. In a representative model, the magnetic field of the star is B ≈ 3.3 × 105 G and the time-averaged accretion rate in the disc is 5.5 × 1016 g s−1. Most of this matter is ejected into conically shaped winds. The numerical model explains the rapid spin-down of AE Aqr through the outflow of angular momentum from the surface of the star to the wind, corona, and disc. The energy budget in the outflows, 9 × 1033 erg s−1, is sufficient for explaining the observed flaring radiation in different wavebands. The time-scale of ejections into the wind matches the short time-scale variability in the light curves of AE Aqr.

scholarly journals On the Short Time Scale Evolutionary History of the Contact Binary VW Cephei

1998 ◽  
Vol 11 (1) ◽  
pp. 396-396
Author(s):  
I. Pustylnik
Keyword(s):  
Evolutionary History ◽  
Light Curves ◽  
Published Data ◽  
Short Time Scale ◽  
Flare Activity ◽  
Considerable Portion ◽  
History Of ◽  
Contact Binary ◽  
Elongation Phase ◽  
Short Time

We study the short-time evolutionary history of the well-known contact binary VW Cep. Our analysis is based partly on the numerous UBV lightcurves obtained at Tartu Observatory, IUE spectra, and samples from the published data. Special attention is given to the effects of asymmetry of the light curves. A higher degree of asymmetry outside the eclipses along with the significant displacements of the brightness maxima in respect to the elongation phase is interpreted as evidence that a considerable portion of the flaring source is concentrated close to the neck connecting the components. We discuss the nature of asymmetry in terms of possible mass exchange and the flare activity and compare the results of our model computations with the record of orbital period variations over the last 60 years.

An Alternative Test Using Algal Cultures for Testing Chemicals for Toxicity

1993 ◽  
Vol 21 (2) ◽  
pp. 196-201
Author(s):  
Søren Achim Nielsen ◽  
Thomas Hougaard
Keyword(s):  
Size Distribution ◽  
Mitotic Activity ◽  
Time Scale ◽  
Test System ◽  
Short Time Scale ◽  
Toxic Substances ◽  
Alternative Test ◽  
Short Time ◽  
Algal Cultures ◽  
Test Cultures

An alternative test is presented, in which algal cultures are used for testing toxic substances. This test system is based on variations in the size distribution of cells in test cultures as a measurement of growth. Thus, inhibition of mitotic activity is used as a measurement for toxic effects. The test can be performed on a short time-scale and is very sensitive to even weak toxic doses.

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