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Thursday, May 7, 2020 | History

2 edition of Shock Waves in the Atmosphere of the Beta Cephei Star bw Vulpeculae. found in the catalog.

Shock Waves in the Atmosphere of the Beta Cephei Star bw Vulpeculae.

Canada. Dept. of Energy, Mines and Resources. Observatories Branch.

Shock Waves in the Atmosphere of the Beta Cephei Star bw Vulpeculae.

by Canada. Dept. of Energy, Mines and Resources. Observatories Branch.

  • 251 Want to read
  • 14 Currently reading

Published .
Written in English


Edition Notes

1

SeriesCanada Dominion Astrophysical Observatory Pub -- V.11,no.06
ContributionsOdgers, G.J., Kushwaha, R.S.
ID Numbers
Open LibraryOL21904452M

1. Introduction. The star β Cephei (HD ) is the prototype of a class of hot pulsating variables. For complete reviews on β Cephei stars, we refer the readers to Aerts and De Cat (), who describe in detail the line-profile variations and to Sterken and Jerzykiewicz (), who give an overview of the photometric behavior of all the β Cep stars known up to that by: 4. ASTRONOMY CH 11 ONLINE QUESTIONS TEST 4. STUDY. Flashcards. Learn. Write. Spell. Test. PLAY. Match. Gravity. Created by. TheStiversChild. Terms in this set (20) Supernovae can produce shock waves that may trigger the birth of stars (T/F). True. Population II stars are first-generation stars formed in the very early Galaxy and are metal poor (T.

The discovery of $\beta$ Cephei stars in low metallicity environments, as well as the difficulty in theoretically explaining the excitation of the pulsation modes observed in some $\beta$ Cephei and hybrid SPB-$\beta$ Cephei pulsators, suggest that the ``iron opacity bump'' provided by stellar models could be underestimated. The more massive the star, the higher up on the main sequence the star will appear. A planetary nebula is the atmosphere of a red giant star slowly expanding away from the star's core to form a shell of gas.

The exiting star’s ultraviolet radiation is also sending out a rapidly expanding shock wave (the half-ring of light) that’s washing through the edge of the molecular cloud like a tidal wave. A supernova (/ ˌ s uː p ər n oʊ v ə / plural: supernovae / ˌ s uː p ər n oʊ v iː / or supernovas, abbreviations: SN and SNe) is a powerful and luminous stellar transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either.


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Shock Waves in the Atmosphere of the Beta Cephei Star bw Vulpeculae by Canada. Dept. of Energy, Mines and Resources. Observatories Branch. Download PDF EPUB FB2

On the origin of shock waves in the beta Cephei star BW Vulpeculae Article (PDF Available) in Astronomy and Astrophysics (2) October with 18 Reads How we measure 'reads'. This means that a more realistic approach, based on a pulsating atmosphere taking into account the occurrence of shocks, is required for the largest amplitude beta Cephei star.

Discovered in in the beta Cephei star beta CMa, the Van Hoof effect, defined as a phase lag of hydrogen compared to metal lines, has often been considered as a detail in the study of these stars. BW Vulpeculae (BW Vul) is remarkable for exciting an extremely strong radial pulsation mode which grows through its outer envelope and forms visible shock features in the atmosphere.

The Beta Cephei stars are a group of variables of spectral type B, whose light and radial velocity periods lie between about three and seven hours. An up-to-date summary of the observational data for individual stars considered to be members of the Beta Cephei group is provided.

The general properties of Beta Cephei stars as determined from a comparison between theory and observation are Cited by: Discovered in in the beta Cephei star beta CMa, the Van Hoof effect, defined as a phase lag of hydrogen compared to metal lines, has often been considered as a detail in the study of these stars.

A hydrodynamical model is generated for the high-amplitude $\beta$ Cephei star BW Vulpeculae, and the spectral line profiles are calculated for different pulsational phases.

The shape parameters of a number of selected ultraviolet lines in BUSS-spectra of the Beta Cephei stars γ Peg and β Cep have been analyzed to determine the principal parameters of the atmospheric velocity field.

We find for both stars a fairly high value (∼5 km s−1) for the microturbulent line-of-sight velocity component, which confirms an earlier result based on lower resolution UV by: 2.

In pulsating stars (long-period variables or Cepheids), the CCFs are double-peaked around maximum light, when the shock front associated with the stellar pulsation is located in the layer probed by the considered mask.

Double-peaked CCFs originate in stellar layers where upward- and downward-moving matter co-exist, on each side of the shock by: 1. The stars a Virginis (Spica), β Cephei, and BW Vulpeculae, representing some of the extremes in variability within the group, were observed in and The observations of Spica, the first of the program, served to demonstrate the value of the new instrumentation for this application.

Abstract: The $\beta$ Cephei stars represent an important class of massive star pulsators probing the evolution of B-type stars and the transition from main sequence to hydrogen-shell burning evolution. By understanding $\beta$ Cep stars, we gain insights into the detailed physics of massive star evolution such as rotational mixing, convective core overshooting, magnetic fields and Cited by: 7.

Three-color light-curve observations of a number of Cephei stars aie reported, together with some observations using a H filter. The large ohserved 2K/Am ratio of the p Cephei stars is discussed.

It is concluded that, while nonradial motion may be present in the p Cephei stars, the large 2K/Am value cannot necessarily be used as an argument to support this by: 7. – 13 Vulpeculae, the third brightest star in Vulpecula, is a blue giant (BIII) located light years away with a visual magnitude of It is around 4 times bigger than our sun.

– 31 Vulpeculae, the constellation’s fourth brightest star, is a yellow giant (G7III) located light years distant of magnitude It has around. Abstract: We undertook a multisite photometric campaign for the Beta Cephei star Nu Eridani.

More than hours of differential photoelectric uvyV photometry were obtained with 11 telescopes during clear nights. The frequency analysis of our measurements shows that the variability of Nu Eri can be decomposed into 23 sinusoidal components, eight of which correspond to independent pulsation Cited by: The (O-C) diagram overcycles of the β Cephei star BW Vulpeculae, which also happens to be the largest-amplitude β Cephei star.

The parabolic shape indicates that the period of the star is increasing at a rate of + seconds per century (Sterken ). Click to enlarge. pected to be, a βCephei star. Section 2 of this paper provides a brief descrip-tion of the historical classification of β Cephei stars including information on asteroseismic space missions.

In Section 3 we describe different groups of variable stars of spectral type B, from which we derive our working definition of β Cephei stars. Astronomy & Astrophysics manuscript no. beta˙Cep c ESO Septem Period change and stellar evolution of Cephei stars Hilding R. Neilson1 and Richard Ignace2 1 Department of Astronomy & Astrophysics, University of Toronto, 50 St.

George Street, Toronto, ON, M5S 3H4, Canada e-mail: [email protected]   Delta Cephei doubles in brightness on a precise schedule, every days. Its brightness changes are tied to its absolute brightness. Learn how this star helped establish the.

ordinary star like the Sun, this collapse is prevented by A) turbulence and upwelling in the atmosphere of the star, thus creating convection. B) gas and radiation pressure pushing outward, thus creating hydrostatic equilibrium.

C) the star's solid core which acts as a barrier. For the dominant frequency we obtain mode identification from the combined photometric and spectroscopic observations. From non-adiabatic pulsation calculations, we show that the frequency of the dominant mode in SY Equ is consistent with the stellar models of much lower effective temperatures than used in many : Jadwiga Daszynska-Daszkiewicz, Andrzej Pigulski.

Available observational data on the properties of beta Cephei stars is reviewed along with recent analytical studies dealing with them.

Topics discussed include the internal structure; effects of rotation and mass loss on the semiconvective regions, evolutionary theories of the beta Cephei instability, and the beat phenomenon. It is the brightest star in Vulpecula.

It is sometimes also known as Lucida Anseris or Lukida. Alpha Vulpeculae forms a wide optical binary with the star 8 Vulpeculae, an orange giant of the spectral type K0III, about light years distant from Earth. 8 Vulpeculae has an apparent magnitude of 23 Vulpeculae.

23 Vulpeculae is the second.Astronomers identify dozens of new Beta Cephei stars 7 Augustby Tomasz Nowakowski Frequency spectrum of the Beta Cephei star TIC computed from KELT (top) and TESS.

Using NASA's prolonged Kepler mission, known as K2, astronomers have identified three new Beta Cephei stars. The newly found trio is an important .