2 edition of nature of the Beta Cephei stars found in the catalog.
nature of the Beta Cephei stars
John Rees Percy
Written in English
|Contributions||Toronto, Ont. University.|
|The Physical Object|
|Pagination||iii, 97 leaves,|
|Number of Pages||97|
STARS and STARS OF THE WEEK Star Count: Created by Jim Kaler, Prof. Emeritus of Astronomy, University of Illinois Learn about stellar spectra in STARS AND THEIR SPECTRA: An Introduction to the Spectral Sequence, Second Ed., with two new chapters and new illustrations, Cambridge University Press (UK or North America), From the Sun to the Stars: the OLLI Lectures provides a linked. Beta Cephei is a triple star with an apparent magnitude that varies from to within a period of days. It is approximately light years distant. The star’s traditional name, Alfirk, derives from the Arabic al-firqah, which means “the flock.” Alfirk serves as the prototype for a class of stars known as the Beta Cephei.
Persei stars, and pulsating Be stars, and less in the classical β Cephei stars. By , however, Sterken and Jerzykiewicz () were able to list 59 certain members, and 79 suspects. Also, a dozen β Cephei stars were discovered in southern clusters, and another dozen or so in northern clusters, bringing the total number to almost a hundred. Cepheus was one of the 48 constellations listed by the second century astronomer Ptolemy, and it remains one of the 88 constellations in the modern times.. The constellation's brightest star is Alpha Cephei, with an apparent magnitude of Delta Cephei is the prototype of an important class of star known as a Cepheid variable. RW Cephei, an orange hypergiant, together with the red.
Both stars are also Beta Cephei variables, which is a class of stars that display several luminosity variations in only a few hours. Typically, the luminosity variations of Beta Cephei stars do not exceed a few hundredths of a magnitude, but in the case of Beta Aa and Ab, the full range of luminosity variations is yet to be determined. Beta Cephei-variabel, även känd som Beta Canis Majoris-stjärna, är en variabel stjärna som har små snabba variationer i magnitud på grund av pulseringar i stjärnans yta, som antas bero på de ovanliga egenskaperna hos järn vid temperaturer på K i dess inre delar. Dessa stjärnor är vanligtvis heta blåvita stjärnor av spektralklass B och bör inte förväxlas med.
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Beta Cephei (β Cephei, abbreviated Beta Cep, β Cep) is a triple star system of the third magnitude in the constellation of on parallax measurements obtained during the Hipparcos mission, it is approximately light-years distant from the is the prototype of the Beta Cephei variable stars.
It consists of a binary pair (designated Beta Cephei A) together with a third Constellation: Cepheus. Beta Cephei variables are sometimes known as β Canis Majoris stars, for reasons which will be mentioned nature of the Beta Cephei stars book.
But, in the General Catalogue of Variable Stars, they are classified as BCEP (with the exception of three apparently shorter-period stars which, for some reason, are sub-classified as BCEPS).They have spectral types of B0-B2 III-V, corresponding to temperatures ofK, i.e. Beta Cephei stars (see -fee-ÿ) (Beta Canis Majoris stars) A small group of pulsating variables, the prototypes being β Cep and β are hot massive luminous stars of spectral types O9 to B3 with short periods of rotation (about 3–7 hours) and a very small variation in visual brightness (about – magnitudes), although the range is much greater at ultraviolet wavelengths.
Using NASA's Transiting Exoplanet Survey Satellite (TESS), astronomers have detected Beta Cephei-type pulsations in an eclipsing binary system known as.
The Beta Cephei nature of Spica. Article Repeated scans at approximately A resolution have been obtained of the A spectral region of 8 bright beta Cep stars.
The data reveal. BETA CEPHEI STARS by (>" Ala.n. P.A. Stamford, (Hons.), University of Tasmania A thesis submitted in fulfilment of the requirements The nature of the 8 Cephei surface motions, whether radial or S Cephei stars have been found to be multiperiodic.
For these stars. Surface motions of the Beta Cephei stars. By Peter Alan Stamford. Download PDF (7 MB) Abstract. The nature of the 8 Cephei surface motions, whether radial or\ud nonradial, has been the subject of considerable controversy. In recent\ud years a number of techniques have been developed for the identification\ud of the pulsation modes operative in.
We present ground-based follow-up photometry in the Geneva seven-colour photometric system of six new candidate beta Cep stars. The variability of these objects was originally found from the HIPPARCOS mission.
From the new data we are able to confirm their beta Cep-type nature, to detect the pulsational frequencies and to identify most of the degrees of the pulsation modes. Abstract.
We give a progress report on an observational program intended to determine detailed chemical abundances of β Cephei stars and constant stars with similar temperature and gravity.
There is some evidence that non-variable stars have a lower metal content than variables, as the recently found pulsation mechanism would suggest. Copernicus scans were made of the Beta Cephei stars Beta Cephei and Alpha Virginis, primarily to examine changes in the C IV A lines on time scales of days and lines near A on time scales of hours.
In addition, count rates in the five detectors were used as a multichannel simultaneous photometer. The variation of light amplitude with wavelength is examined in Beta Cep and discussed. We report a multisite photometric campaign for the Beta Cephei star 12 Lacertae.
hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with 9 telescopes during nights. Our frequency analysis results in the detection of 23 sinusoidal signals in the light curves. Eleven of those correspond to independent pulsation modes, and.
beta Cephei stars are a group of short-period intrinsic variables on the upper main sequence. Finding the excitation mechanism for them and other early-type variables is a long standing problem.
Using NASA's prolonged Kepler mission, known as K2, astronomers have identified three new Beta Cephei stars. The newly found trio is an important addition to the still short list of known stars.
The nature of the 8 Cephei surface motions, whether radial or nonradial, has been the subject of considerable controversy.
In recent years a number of techniques have been developed for the identification of the pulsation modes operative in variable stars. In this thesis, these mode identification techniques are explored theoretically and applied to some members of the 8 Cephei group.
Beta Cephei variables, also known as Beta Canis Majoris stars, are variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures ofK in their interiors. These stars are usually hot blue-white stars of spectral class B and should not be confused with Cepheid variables, which.
Cite this paper as: Cugier H., Boratyn D. () Mode identification in beta Cephei stars from UV observations. In: Heber U., Jeffery C.S. (eds) The Atmospheres of Early-Type Stars. OBSERVED IN BETA CEPHEI STARS IN NGC Fourier Fitting of Frequencies to Data Results The Star The Star The evolutionary state of the /3 Cephei stars (c) The nature of the physical mechanism driving the pulsations (d) The detailed modes of pulsation (e).
The All Sky Automated Survey (ASAS) data, covering nearly 70% of the whole sky south of declination +28 deg, were recently used to discover about Beta Cephei stars brighter than V~ mag. As this means a nearly fourfold increase in the number of known stars of this type, new possibilities in studying these pulsators open up, including.
VV Cephei is an eclipsing binary star system located 4, ly from Earth in the constellation Cepheus. With a radius between 1, and 1, times that of the Sun, it is one of the largest stars known.
We present the results of a magnetic survey of a sample of eight beta Cephei stars and 26 Slowly Pulsating B stars with FORS1 at the VLT. A weak mean. Cephei stars have been computed with Carson's new radiative opacities from the zero-age main sequence up to the stage of core helium ignition.
The new models lying off the zero-age main sequence possess cooler effective temperatures than do models based on earlier opacities, and cross the Delta Cephei, prototype star of the class of Cepheid variables, in the constellation Cepheus.
Its apparent visual magnitude at minimum is and at maximumchanging in a regular cycle of about five days and nine hours. Its variations in brightness were discovered in by the English.A Beta Cephei star is a pulsating variable, of spectral type O9 to B3, with a short period (3 to 6 hours) and small magnitude range of to (less than those of Cepheid variables).Beta Cephei stars are confined to a narrow band of the Hertzsprung-Russell diagram near the end of core hydrogen-burning stars of roughly 10 to 20 solar masses.