Синтез экспоненциальных сплайнов на основе моделей линейных электрических цепей

Дано обґрунтування щодо застосування при визначенні параметрів лінійних електричних кіл і їх компонентів класу експоненціальних випробувальних сигналів (ВС) із метою отримання уніфікованого відгуку, форма якого є зручної до аналізу та контролю. Наведені основні визначення та методологія щодо синтезу експоненціальних сплайнів, що можуть бути безпосередньо сформовані у вигляді електричного сигналу у лінійних електричних колах.The grounds of application are given during measuring of parameters linear electric circuits and their components of class of exponential test signals in order to receive compatible response, the form which is comfortable for analysis and control. The main definitions and the synthesis of exponential splines methodology are given, which can be formulated as electric signal in linear electric circuits.Дано обоснование применения при измерениях параметров линейных электрических цепей и их компонентов класса экспоненциальных испытательных сигналов с целью получения унифицированного отклика, форма которого является удобной для анализа и контроля. Даны основные определения и методология синтеза экспоненциальных сплайнов, которые могут быть непосредственно сформированы в виде электрического сигнала в линейных электрических цепях

A Luminous Red Nova in M31 and its Progenitor System

We present observations of M31LRN 2015 (MASTER OT J004207.99+405501.1), discovered in M31 in January 2015, and identified as a rare and enigmatic luminous red nova (LRN). Spectroscopic and photometric observations obtained by the Liverpool Telescope showed the LRN becoming extremely red as it faded from its M(V) = -9.4 +/- 0.2 peak. Early spectra showed strong Halpha emission that weakened over time as a number of absorption features appeared, including Na I D and Ba II. At later times strong TiO absorption bands were also seen. A search of archival Hubble Space Telescope data revealed a luminous red source to be the likely progenitor system, with pre-outburst Halpha emission also detected in ground-based data. The outburst of M31LRN 2015 shows many similarities, both spectroscopically and photometrically, with that of V838 Mon, the best studied LRN. We finally discuss the possible progenitor scenarios

The MASTER-II network of robotic optical telescopes. First results

The main stages in the creation of the Russian segment of the MASTER network of robotic telescopes is described. This network is designed for studies of the prompt optical emission of gammaray bursts (GRBs; optical emission synchronous with the gamma-ray radiation) and surveys of the sky aimed at discovering uncataloged objects and photometric studies for various programs. The first results obtained by the network, during its construction and immediately after its completion in December 2010, are presented. Eighty-nine alert pointings at GRBs (in most cases, being the first ground telescopes to point at the GRBs) were made from September 2006 through July 2011. The MASTER network holds first place in the world in terms of the total number of first pointings, and currently more than half of first pointings at GRBs by ground telescopes are made by the MASTER network. Photometric light curves of GRB 091020, GRB 091127, GRB 100901A, GRB 100906A, GRB 10925A, GRB 110106A, GRB 110422A, and GRB 110530A are presented. It is especially important that prompt emission was observed for GRB 100901A and GRB 100906A, and thar GRB 091127, GRB 110422A, and GRB 110106A were observed from the first seconds in two polarizations. Very-wide-field cameras carried out synchronous observations of the prompt emission of GRB 081102, GRB 081130B, GRB 090305B, GRB 090320B, GRB 090328, and GRB 090424. Discoveries of Type Ia supernovae are ongoing (among them the brightest supernova in 2009): 2008gy, 2009nr, 2010V, and others. In all, photometry of 387 supernovae has been carried out, 43 of which were either discovered or first observed with MASTER telescopes; more than half of these are Type Ia supernovae. Photometric studies of the open clusters NGC 7129 and NGC 7142 have been conducted, leading to the discovery of 38 variable stars. Sixty-nine optical transients have been discovered. © 2013 Pleiades Publishing, Ltd

MASTER OT J004207.99+405501.1/M31LRN 2015 luminous red nova in M31: Discovery, light curve, hydrodynamics and evolution

We report the discovery and multicolour (VRIW) photometry of the rare explosive star MASTEROT J004207.99+405501.1 - a luminous red nova - in theAndromeda galaxy M31N2015-01a. We use our original light curve acquired with identical MASTER Global Robotic Net telescopes in one photometric system: VRI during the first 30 d and W (unfiltered) during 70 d. Also, we added published multicolour photometry data to estimate the mass and energy of the ejected shell and we discuss the likely formation scenarios of outbursts of this type. We propose an interpretation of the explosion that is consistent with an evolutionary scenario where the merging of stellar components or the disruption of the common envelope of a close binary can explain some luminous red novae. Radiative hydrodynamic simulations of a luminous red nova were carried out in extended parameter space to fit its light curves. We find that the multicolour passband light curves of the luminous red nova are consistent with an initial common envelope radius of 10 R⊙, a merger mass of 3M⊙ and an explosion energy of 3 × 1048 erg. As a result, the phenomenon of novae consists of two classes: classical nuclear novae and more rare events (red novae) connected with the loss of compact common envelopes. © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society

MASTER OT J004207.99+405501.1/M31LRN 2015 luminous red nova in M31: discovery, light curve, hydrodynamics and evolution

We report the discovery and multicolor (VRIW) photometry of a rare explosive star MASTER OT J004207.99+405501.1 - a luminous red nova - in the Andromeda galaxy M31N2015-01a. We use our original light curve acquired with identical MASTER Global Robotic Net telescopes in one photometric system: VRI during first 30 days and W (unfiltered) during 70 days. Also we added publishied multicolor photometry data to estimate the mass and energy of the ejected shell, and discuss the likely formation scenarios of outbursts of this type. We propose the interpretation of the explosion, that is consistent with the evolutionary scenario where star merger is a natural stage of the evolution of close-mass stars and may serve as an extra channel for the formation of nova outbursts.Comment: 16 pages, 9 figures, 2 tables, accepted to MNRA