Physical properties of γ Doradus pulsating stars and their relationship with long-period δ Scuti variables

2019 ◽  
Vol 19 (1) ◽  
pp. 001 ◽  
Author(s):  
Sheng-Bang Qian ◽  
Lin-Jia Li ◽  
Jia-Jia He ◽  
Jia Zhang ◽  
Li-Ying Zhu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Pulsating Stars ◽  
Long Period

scholarly journals Physical properties of V1329 Cygni

1982 ◽  
Vol 70 ◽  
pp. 169-171
Author(s):  
T. Iijima
Keyword(s):  
Light Curve ◽  
Physical Properties ◽  
Type Systems ◽  
Mass Function ◽  
Eclipsing Binary ◽  
Long Period ◽  
Binary Model

In this paper, I shall present another model for V1329 Cyg. Grygar et al. (1979) proposed a long period eclipsing binary model consisting of a massive M giant and a hot component. Some problems, however, have remained on the binary model. Namely, the mass function is too large, the amplitude of the light variations changes from period to period, the light curve differs from that of Algol type systems and is similar to long period binaries, and so on (Iijima et al. 1981). It has been believed that some peculiarities in the system could explain those problems. Recently however, some phenomena which are inconsistent with the binary model were observed (Iijima and Mammano 1981).

scholarly journals Light Curve Analysis of Long Period Pulsating Stars with the Wavelet Method: The semiregular star V Boo

1995 ◽  
Vol 155 ◽  
pp. 417-418 ◽  
Author(s):  
K. Szatmáry ◽  
J. Gál ◽  
L. L. Kiss
Keyword(s):  
Stellar Evolution ◽  
Curve Analysis ◽  
Point Of View ◽  
Light Curves ◽  
Data Series ◽  
Strong Fluctuation ◽  
Light Curve Analysis ◽  
Pulsating Stars ◽  
Long Period ◽  
Data Banks

AbstractWe have collected long data series of some SR and Mira stars from data banks. In many cases the light curves show strong fluctuation or variation in the period, phase and amplitude. The detection of the significant changes of these parameters is important from the point of view of pulsation theory and stellar evolution. We present here the analysis of V Boo. The used method is the Fourier and wavelet analysis in order to point out the modulations in the frequency and amplitude.

Variability of long-period pulsating stars. II. Additional parameters for classifying stars

Astrophysics ◽  
2006 ◽  
Vol 49 (4) ◽  
pp. 506-522 ◽  
Author(s):  
V. I. Marsakova ◽  
I. L. Andronov
Keyword(s):  
Pulsating Stars ◽  
Long Period

scholarly journals Tomography of the Atmosphere of the Mira Variable Z Oph

2002 ◽  
Vol 185 ◽  
pp. 428-431
Author(s):  
A. Jorissen ◽  
M. Dedecker ◽  
B. Plez ◽  
R. Alvarez ◽  
D. Gillet ◽  
...  
Keyword(s):  
Shock Wave ◽  
Velocity Field ◽  
Optical Spectrum ◽  
Variable Stars ◽  
Pulsating Stars ◽  
Long Period ◽  
Synthetic Spectra ◽  
Mira Variable ◽  
Period Variable ◽  
Tomographic Technique

AbstractThe new tomographic technique devised by Alvarez et al. (2000) to explore the velocity field across the atmosphere of long-period variable stars (LPVs) is applied to the Mira variable Z Oph. The method cross-correlates the optical spectrum with numerical masks constructed from synthetic spectra and probing layers of increasing depths. This technique reveals that the line doubling often observed in LPVs around maximum light is the signature of the shock wave propagating in the atmosphere of these pulsating stars.

scholarly journals September epsilon Perseids observed by the Czech Fireball Network

2019 ◽  
Vol 629 ◽  
pp. A137 ◽  
Author(s):  
Lukáš Shrbený ◽  
Pavel Spurný
Keyword(s):  
Physical Properties ◽  
High Activity ◽  
Orbital Period ◽  
Parent Body ◽  
Meteor Shower ◽  
Meteor Showers ◽  
Long Period ◽  
Heliocentric Orbits ◽  
Right Ascension ◽  
Period Comet

We present 25 photographic fireballs belonging to the September epsilon Perseid (SPE, IAU #208) meteor shower observed by the Czech part of the European Fireball Network in 2013–2017. Exceptional high activity of bright photographic fireballs was observed in 2013, while a lower activity, but still higher than in other years, was observed in the period of 2015–2017. Physical properties of these SPE fireballs were studied and compared to other meteor showers. Perseids are found to be the closest analog to SPE. Corrected geocentric radiant of the 2013 outburst fireballs was determined for solar longitude 167.20° and has right ascension 47.67 ± 0.04° and declination 39.493 ± 0.013° (J2000.0). On the basis of determined heliocentric orbits the parent body of the shower is an unknown long-period comet on retrograde orbit with an orbital period of the order of a thousand years.

scholarly journals Double Mode Pulsating Stars and Opacity Changes

1989 ◽  
Vol 111 ◽  
pp. 248-248
Author(s):  
G.K. Andreasen
Keyword(s):  
Physical Properties ◽  
Variable Stars ◽  
Period Ratio ◽  
Pulsating Stars ◽  
Temperature Range ◽  
Ratio Data ◽  
Mass Calibration ◽  
Scuti Stars ◽  
Δ Scuti Stars

AbstractThe basic physical properties of double mode Cepheids and double mode δ Scuti stars are still highly controversial. Based on results of very recent opacity calculations a detailed consistent, possible solution of the problem of the nature of double mode variable stars has been developed. Extensive studies have been performed to establish the rules governing the morphology of the period ratio diagrams. An ideal reproduction of the period ratio data for both stellar types are obtained assuming an increase of the Cox-Steward opacity by a factor of about 2.5 in the temperature range from 1.5 X 105K to 8.0 X 105K. Consequences for the mass calibration of Petersen diagrams are evaluated.

scholarly journals Optical interferometry and Gaia parallaxes for a robust calibration of the Cepheid distance scale

2017 ◽  
Vol 12 (S330) ◽  
pp. 305-308
Author(s):  
Pierre Kervella ◽  
Antoine Mérand ◽  
Alexandre Gallenne ◽  
Boris Trahin ◽  
Simon Borgniet ◽  
...  
Keyword(s):  
Zero Point ◽  
Optical Interferometry ◽  
Radial Velocities ◽  
Distance Scale ◽  
Modeling Tool ◽  
Pulsating Stars ◽  
Long Period ◽  
Light Echoes ◽  
Pulsation Model ◽  
Gaia Dr2

AbstractWe present the modeling tool we developed to incorporate multi-technique observations of Cepheids in a single pulsation model: the Spectro-Photo-Interferometry of Pulsating Stars (SPIPS). The combination of angular diameters from optical interferometry, radial velocities and photometry with the coming Gaia DR2 parallaxes of nearby Galactic Cepheids will soon enable us to calibrate the projection factor of the classical Parallax-of-Pulsation method. This will extend its applicability to Cepheids too distant for accurate Gaia parallax measurements, and allow us to precisely calibrate the Leavitt law's zero point. As an example application, we present the SPIPS model of the long-period Cepheid RS Pup that provides a measurement of its projection factor, using the independent distance estimated from its light echoes.

Advances in understanding cognition and learning in cattle

2021 ◽  
pp. 17-36
Author(s):  
Maria Vilain Rørvang ◽  
◽  
Christian Nawroth ◽  
Keyword(s):  
Cognitive Development ◽  
Physical Properties ◽  
Work Environment ◽  
Current Knowledge ◽  
Group Cohesion ◽  
Spatial Cues ◽  
Cognitive Capacities ◽  
Long Period ◽  
Cognition And Learning ◽  
Learning And Cognition

Understanding the cognitive capacities of cattle is central when designing husbandry environments and developing handling regimes. This chapter outlines the current knowledge on cattle learning and cognition, with special emphasis on their socio-cognitive capacities. Cattle easily learn features and spatial cues and can remember these for a long period of time. They are also highly trainable and can be taught complex tasks. While there is a gap in knowledge of how cattle recognise the physical properties of their environment, there is a good understanding about their social discrimination and recognition skills, all of which are of high relevance for maintaining group cohesion. Applied research should focus on how husbandry environments and daily management routines can be adapted to foster cattle’s cognitive development. By using their cognitive capacities in the conceptualisation of handling regimes, we may further ensure a safer work environment for handlers whilst at the same time safeguard the welfare of the animals.

scholarly journals Changes in soil physical properties under the effect of irrigation

2021 ◽  
Vol 939 (1) ◽  
pp. 012081
Author(s):  
Yu Kenjaev ◽  
A Tursunkulova
Keyword(s):  
Physical Properties ◽  
Irrigation Water ◽  
Soil Compaction ◽  
Soil Layer ◽  
Soil Physical Properties ◽  
Soil Layers ◽  
Long Period ◽  
Bulk Mass ◽  
General Physical

Abstract The mechanical composition of soils in the middle reaches of the Zarafshan River (Jambay, Samarkand, Payarik, Ishtikhon, Kattakurgan and Narpay districts) and the processes of formation of soil layers under the influence of irrigation water of general physical properties were scientifically analyzed. In this case, the inflow of the Zarafshan River played an important role in the formation of light agroirrigation strata. An increase in nutrients and humus with an increase in the amount of physical sludge over a long period of time (35–40 years) is positively assessed for thickening of the soil layer, but leads to an increase in bulk mass of 0.15–0.3 g / cm3 and soil compaction.

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