scholarly journals The evolution of photospheric temperature in nova V2676 Oph toward the formation of C2and CN during its near-maximum phase

2016 ◽  
Vol 68 (5) ◽  
pp. 87 ◽  
Author(s):  
Hideyo Kawakita ◽  
Akira Arai ◽  
Mitsugu Fujii
Keyword(s):  
Maximum Phase ◽  
Photospheric Temperature

scholarly journals Influence of spacer chain lengths and polar terminal groups on the mesomorphic properties of tethered 5-phenylpyrimidines

2009 ◽  
Vol 5 ◽  
Author(s):  
Gundula F Starkulla ◽  
Elisabeth Kapatsina ◽  
Angelika Baro ◽  
Frank Giesselmann ◽  
Stefan Tussetschläger ◽  
...  
Keyword(s):  
Terminal Group ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Maximum Phase ◽  
X Ray ◽  
Smectic A ◽  
Polar Groups ◽  
Chain Lengths ◽  
Mesomorphic Properties ◽  
Phase Width

Based on 5-(4-hydroxyphenyl)-2-octylpyrimidine 8, 5-phenylpyrimidine derivatives 3–7, 9 with different spacer chain lengths (C2 up to C6) and different terminal polar groups (Br, Cl, N3, OH, CN) were synthesized by etherification and nucleophilic substitution. The mesomorphic behaviour of these compounds was investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS and SAXS) and revealed smectic A mesophases for bromides, chlorides and azides 3, 4 and 6. For these compounds a maximum phase width was observed for the C5 spacer regardless of the terminal group, whereas the hydroxy- and cyano-substituted derivatives 5 and 7, respectively, were non mesomorphic and showed only melting transitions.

scholarly journals A great space weather event in February 1730

2018 ◽  
Vol 616 ◽  
pp. A177 ◽  
Author(s):  
Hisashi Hayakawa ◽  
Yusuke Ebihara ◽  
José M. Vaquero ◽  
Kentaro Hattori ◽  
Víctor M. S. Carrasco ◽  
...  
Keyword(s):  
Solar Activity ◽  
East Asia ◽  
Magnetic Storm ◽  
East Asian ◽  
Active Phase ◽  
Magnetic Storms ◽  
Historical Records ◽  
Maximum Phase ◽  
Weather Event ◽  
Space Weather Event

Aims. Historical records provide evidence of extreme magnetic storms with equatorward auroral extensions before the epoch of systematic magnetic observations. One significant magnetic storm occurred on February 15, 1730. We scale this magnetic storm with auroral extension and contextualise it based on contemporary solar activity. Methods. We examined historical records in East Asia and computed the magnetic latitude (MLAT) of observational sites to scale magnetic storms. We also compared them with auroral records in Southern Europe. We examined contemporary sunspot observations to reconstruct detailed solar activity between 1729 and 1731. Results. We show 29 auroral records in East Asian historical documents and 37 sunspot observations. Conclusions. These records show that the auroral displays were visible at least down to 25.8° MLAT throughout East Asia. In comparison with contemporary European records, we show that the boundary of the auroral display closest to the equator surpassed 45.1° MLAT and possibly came down to 31.5° MLAT in its maximum phase, with considerable brightness. Contemporary sunspot records show an active phase in the first half of 1730 during the declining phase of the solar cycle. This magnetic storm was at least as intense as the magnetic storm in 1989, but less intense than the Carrington event.

scholarly journals Acarocomplex of grape plantations of the South of Ukraine

2020 ◽  
pp. 12-16
Author(s):  
Yu. Klechkovskyi ◽  
K. Shmatkovska
Keyword(s):  
Species Composition ◽  
Growing Season ◽  
Spider Mites ◽  
Trophic Groups ◽  
Maximum Phase ◽  
Trophic Links ◽  
Grape Varieties ◽  
Southern Ukraine ◽  
Intensive Growth

Goal. To determine the species composition, dominant species, and territorial distribution of predatory and herbivorous ticks (phytophages) in the vineyards of southern Ukraine. Methods. Field — route surveys of vineyards to study the fauna, trophic links and colonization of vineyards with ticks. Laboratory — determination of the species composition of representatives of the acarofauna of vineyards. Results. During the study period, 17 species of ticks belonging to different trophic groups were identified, among which ticks dominate — phytophages of the Tetranychidae and Eriophyidae families. The most common among them were mites — phytophages, namely spider mites (Shhizotetranychus Oud., Tetranychus turkestanicus Ug.et Nich). Pests during the growing season go through four phases: prodromal, eruptive, gradation maximum and crisis. The graduation maximum phase, which is characterized by their greatest number, was noted during the period of intensive growth of berries and falls at the end of June — beginning of August (BBCH 71—79). The dynamics of the number of ticks by varieties is shown. The varieties most susceptible to spider mites were identified, the period of technical ripeness of which is medium, late or very late. Conclusions. Identified 17 species of ticks belonging to different trophic groups: phytophages, acariphages and mycophages. Based on observations of changes in the number of pests on vineyards during the growing season, four phases are distinguished. The graduation maximum phase occurs at the end of June — beginning of August (VVSN 71—79). It was established that all the studied grape varieties were populated by mites to varying degrees, the most susceptible were varieties of medium and late ripening.

Measurement of the refractive index of lenses from the maximum phase difference of the total internal reflection with a polarization camera

2021 ◽  
Vol 60 (10) ◽  
pp. B106
Author(s):  
Ju-Yi Lee ◽  
Chia-Yu Chiang ◽  
Wei-Yi Sung ◽  
Tzu-Yang Weng ◽  
Jing-Heng Chen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Phase Difference ◽  
Total Internal Reflection ◽  
Internal Reflection ◽  
Maximum Phase ◽  
Polarization Camera

scholarly journals On the Nature of Maser Sources in Infrared Stars

1975 ◽  
Vol 67 ◽  
pp. 175-177
Author(s):  
V. V. Burdjuzha ◽  
T. V. Ruzmaikina
Keyword(s):  
Dust Shell ◽  
Infrared Stars ◽  
Maser Sources ◽  
Photospheric Temperature

Supergiant infrared stars with OH maser emissions, like NML Cyg, VY CMa, and VX Sgr, are discussed assuming a model consisting of a star with a photospheric temperature of about 2000 K and a radius of R ∼ 2 × 1014 cm surrounded by a gas and dust shell. A possible similarity with OH Miras is mentioned.

scholarly journals Super-luminous Type II supernovae powered by magnetars

2018 ◽  
Vol 613 ◽  
pp. A5 ◽  
Author(s):  
Luc Dessart ◽  
Edouard Audit
Keyword(s):  
Light Curve ◽  
Spectroscopic Properties ◽  
Radiation Hydrodynamics ◽  
Equal Proportion ◽  
Type Ii ◽  
Standard Type ◽  
Fluid Instabilities ◽  
Dense Shell ◽  
Standard Energy ◽  
Photospheric Temperature

Magnetar power is believed to be at the origin of numerous super-luminous supernovae (SNe) of Type Ic, arising from compact, hydrogen-deficient, Wolf-Rayet type stars. Here, we investigate the properties that magnetar power would have on standard-energy SNe associated with 15–20 M⊙ supergiant stars, either red (RSG; extended) or blue (BSG; more compact). We have used a combination of Eulerian gray radiation-hydrodynamics and non-LTE steady-state radiative transfer to study their dynamical, photometric, and spectroscopic properties. Adopting magnetar fields of 1, 3.5, 7 × 1014 G and rotational energies of 0.4, 1, and 3 × 1051 erg, we produce bolometric light curves with a broad maximum covering 50–150 d and a magnitude of 1043–1044 erg s−1. The spectra at maximum light are analogous to those of standard SNe II-P but bluer. Although the magnetar energy is channelled in equal proportion between SN kinetic energy and SN luminosity, the latter may be boosted by a factor of 10–100 compared to a standard SN II. This influence breaks the observed relation between brightness and ejecta expansion rate of standard Type II SNe. Magnetar energy injection also delays recombination and may even cause re-ionization, with a reversal in photospheric temperature and velocity. Depositing the magnetar energy in a narrow mass shell at the ejecta base leads to the formation of a dense shell at a few 1000 km s−1, which causes a light-curve bump at the end of the photospheric phase. Depositing this energy over a broad range of mass in the inner ejecta, to mimic the effect of multi-dimensional fluid instabilities, prevents the formation of a dense shell and produces an earlier-rising and smoother light curve. The magnetar influence on the SN radiation is generally not visible prior to 20–30 d, during which one may discern a BSG from a RSG progenitor. We propose a magnetar model for the super-luminous Type II SN OGLE-SN14-073.

scholarly journals Plasma transport along discrete auroral arcs and its contribution to the ionospheric plasma convection

2008 ◽  
Vol 26 (11) ◽  
pp. 3279-3293 ◽  
Author(s):  
A. Kullen ◽  
S. Buchert ◽  
T. Karlsson ◽  
T. Johansson ◽  
S. Lileo ◽  
...  
Keyword(s):  
Plasma Flow ◽  
Strong Dependence ◽  
Background Plasma ◽  
Plasma Transport ◽  
Plasma Convection ◽  
Plasma Flows ◽  
Maximum Phase ◽  
Field Peak ◽  
Auroral Arcs

Abstract. The role of intense high-altitude electric field (E-field) peaks for large-scale plasma convection is investigated with the help of Cluster E-field, B-field and density data. The study covers 32 E-field events between 4 and 7 RE geocentric distance, with E-field magnitudes in the range 500–1000 mV/m when mapped to ionospheric altitude. We focus on E-field structures above the ionosphere that are typically coupled to discrete auroral arcs and their return current region. Connected to such E-field peaks are rapid plasma flows directed along the discrete arcs in opposite directions on each side of the arc. Nearly all the E-field events occur during active times. A strong dependence on different substorm phases is found: a majority of intense E-field events appearing during substorm expansion or maximum phase are located on the nightside oval, while most recovery events occur on the dusk-to-dayside part of the oval. For most expansion and maximum phase cases, the average background plasma flow is in the sunward direction. For a majority of recovery events, the flow is in the anti-sunward direction. The net plasma flux connected to a strong E-field peak is in two thirds of the cases in the same direction as the background plasma flow. However, in only one third of the cases the strong flux caused by an E-field peak makes an important contribution to the plasma transport within the boundary plasma sheet. For a majority of events, the area covered by rapid plasma flows above discrete arcs is too small to have an effect on the global convection. This questions the role of discrete auroral arcs as major driver of plasma convection.

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