Flare Activity and Spotgroup Development

Author(s):  
V. Bumba ◽  
L. Křivský ◽  
M. J. Martres ◽  
I. Soru-Iscovici
Keyword(s):  
1998 ◽  
Vol 11 (1) ◽  
pp. 396-396
Author(s):  
I. Pustylnik

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.


1998 ◽  
Vol 11 (1) ◽  
pp. 398-398
Author(s):  
Kenji Tanabe

Propagation of the surface waves of the lobe-filing components of close binary systems is investigated theoretically. Such waves are considered to be analogous to the gravity waves of water on the earth. As a result, the equations of the surface wave in the rotating frame of reference are reduced to the so-called Kortewegde Vries (KdV) equation and non-linear Schroedinger (NLS) equation according to its ”depth”. Each of these equations is known to have the solution of soliton. When this soliton is sent to the other component of the binary system through the Lagrangian point, it can give rise to the flare activity observed in some kinds of close binary systems.


2021 ◽  
Vol 65 (6) ◽  
pp. 507-517
Author(s):  
S. A. Yazev ◽  
E. S. Isaeva ◽  
Yu. V. Ishmukhametova

2021 ◽  
Author(s):  
Sam Peter Coupland

Abstract bp's strategy sets out a decadeof delivery towards becoming a net zero company by 2050 (or sooner) with targets set for emissions from operations to fall by between 30-35% by 2030. In pursuit of this, a North Sea carbonplan has been developed to identify, track, and deliver sustainable emission reductions (SERs) activities. Proactive engagement has been essential in delivery of this plan, helping to empower colleagues to prioritize emissions reduction opportunities. To date, the plan has identified more than 80 SERs across bp's North Seaportfolio and cumulatively reduced carbonemissions by more than 400,000 tonnes from offshore operations. It is on track to reduce almost 70,000tonnes of carbon from operations in 2021 alone. Whilst it is recognised that this represents only part of bp's annual scope 1 emissions in the North Sea; this is a lasting operational improvement. The plan has also significantly reduced sources of unknown flare gas. It also contributed to a 45% reduction in flare activity in 2020 vs 2019as well as achieving zero routine flaringon two of bp's major west of Shetland installations from October 2020 The plan has more deeply embedded emissions tracking in operations on and offshore and helped further improve working practices on flaring and energy efficiency in general.


2017 ◽  
Vol 466 (3) ◽  
pp. 2542-2546 ◽  
Author(s):  
L. Šmelcer ◽  
M. Wolf ◽  
H. Kučáková ◽  
F. Bílek ◽  
P. Dubovský ◽  
...  

1998 ◽  
Vol 499 (2) ◽  
pp. 898-904 ◽  
Author(s):  
Takako T. Ishii ◽  
Hiroki Kurokawa ◽  
Tsutomu T. Takeuchi
Keyword(s):  

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