Observational Constraints on the Common Envelope Phase

The common envelope phase was first proposed more than forty years ago to explain the origins of evolved, close binaries like cataclysmic variables. It is now believed that the phase plays a critical role in the formation of a wide variety of other phenomena ranging from type Ia supernovae through to binary black holes, while common envelope mergers are likely responsible for a range of enigmatic transients and supernova imposters. Yet, despite its clear importance, the common envelope phase is still rather poorly understood. Here, we outline some of the basic principles involved, the remaining questions as well as some of the recent observational hints from common envelope phenomena - namely planetary nebulae and luminous red novae - which may lead to answering these open questions.Comment: 29 pages, 8 figures. To appear in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds. Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556

Type Ia Supernovae Inside Planetary Nebulae (SNIPs)

We estimate that the fraction of type Ia supernovae (SNe Ia) exploding inside planetary nebulae (PNe), termed SNIPs, is at least 20%. We based this on (i) sodium absorption lines in some SN Ia, (ii) hydrogen emission line from circumstellar matter, and (iii) X-ray morphology of some SN Ia remnants that resembles PNe. We conclude that the two scenarios most contributing to SNe Ia are the core degenerate and the double degenerate scenarios. The work is published in Tsebrenko & Soker [3]

ОБҐРУНТУВАННЯ ЗМЕНШЕННЯ ПОТУЖНОСТІ ЕЛЕКТРОДВИГУНА ГІДРОПРИВОДУ МЕТОДОМ ЕКВІВАЛЕНТНОЇ ПОТУЖНОСТІ

The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is  justifiedОбосновано снижение установленной мощности приводного электродвигателя кранового механизма на основе анализа затрат энергии и сопоставления эквивалентной мощности гидростатического привода и асинхронного привода с фазным роторомОбґрунтовано зменшення встановленої потужності приводного електродвигуна кранового механізму на основі аналізу витрат енергії й зіставлення еквівалентної потужності гідростатичного приводу і асинхронного приводу з фазним роторо

GROUNDING THE REDUCTION OF POWER OF THE HYDRAULIC DRIVE ELECTRIC MOTOR BY EQUIVALENT POWER METHOD

The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is justified

STAND FOR INVESTIGATION OF THE ADJUSTABLE HYDROSTATIC DRIVE OF THE HOISTING MECHANISM

Analysis of the experimental stand design for research of operation of the hydrostatic drive of the hoisting mechanism with a low-moment hydraulic motor is carried out. The use of the set of measuring and registration equipment based on the experiment planning is grounded