scholarly journals Nonradial Pulsations in Classical Cepheids of The Magellanic Clouds

2004 ◽  
Vol 193 ◽  
pp. 498-501 ◽  
Author(s):  
Paweł Moskalik ◽  
Zbigniew Kołaczkowski ◽  
Tomasz Mizerski
Keyword(s):  
Frequency Analysis ◽  
Magellanic Clouds ◽  
Classical Cepheid ◽  
Classical Cepheids ◽  
Cepheid Variables ◽  
Low Amplitude ◽  
Triple Mode ◽  
Nonradial Oscillations

AbstractWe have performed systematic frequency analysis of the LMC Cepheids observed by OGLE project. Several new types of pulsation behaviour are identified, including triple-mode and amplitude-modulated double-mode pulsations. In ~ 10% of the first overtone Cepheids we find low amplitude secondary periodicities corresponding to nonradial modes. This is the first evidence for excitation of nonradial oscillations in Classical Cepheid variables.

scholarly journals Observations of Classical Cepheids

1980 ◽  
Vol 5 ◽  
pp. 477-478
Author(s):  
Barry F. Madore
Keyword(s):  
Sample Size ◽  
Effective Temperature ◽  
Milky Way ◽  
Magellanic Clouds ◽  
Amplitude Dependence ◽  
Precise Form ◽  
Classical Cepheids ◽  
Low Amplitude

Calibration of the Period-Luminosity relation for Classical Cepheids is still far from settled: the debate continues as to whether there is a unique relation from galaxy to galaxy and what the precise form is in any one system. In the Milky Way we suffer from poor sample size; in the Magellanic Clouds it is still a matter of low accuracy in the observations. Work is in progress at several observatories to alleviate both of these problems through studying not only galactic Cepheids but also those in the LMC, SMC, M33 and NGC 300.Arellano & Percy (CTI0/DD0) have begun a photoelectric monitoring of the apparently brightest F & G supergiants in the Milky Way. The aim is to detect near-by very-low-amplitude Cepheids which are binaries or are intrinsically low amplitude variables. This should provide a better qualitative hold on the sense of the amplitude dependence on effective temperature, as well as the true fequency of the cepheid phenomenon.

scholarly journals IRAS observations of classical cepheids

1987 ◽  
Vol 122 ◽  
pp. 227-228
Author(s):  
C. J. Butler ◽  
H. P. Deasy ◽  
P. A. Wayman
Keyword(s):  
Mass Loss ◽  
Classical Cepheids ◽  
Cepheid Variables ◽  
Loss Rates

IRAS observations of sources identified with cepheid variables are used to give estimates of observed mass-loss rates for those stars.

scholarly journals Mode identification of three low-amplitude classical Cepheids: V1334 Cyg, V440 Per and V636 Cas

2012 ◽  
Vol 426 (1) ◽  
pp. 398-401 ◽  
Author(s):  
V. V. Kovtyukh ◽  
R. E. Luck ◽  
F. A. Chekhonadskikh ◽  
S. I. Belik
Keyword(s):  
Mode Identification ◽  
Classical Cepheids ◽  
Low Amplitude

scholarly journals Nonradial oscillations in classical Cepheids: the problem revisited

2007 ◽  
Vol 465 (3) ◽  
pp. 937-942 ◽  
Author(s):  
C. Mulet-Marquis ◽  
W. Glatzel ◽  
I. Baraffe ◽  
C. Winisdoerffer
Keyword(s):  
Classical Cepheids ◽  
Nonradial Oscillations

scholarly journals A Preliminary Study of the Classical Cepheid P-L Relation in the R, I Photometric System

1975 ◽  
Vol 67 ◽  
pp. 183-190
Author(s):  
J. D. Fernie
Keyword(s):  
Photometric System ◽  
Classical Cepheid ◽  
Classical Cepheids ◽  
Preliminary Study ◽  
Colour Term ◽  
Image Position

It is pointed out that observational work on Cepheids in the R, I photometric system offers a number of advantages: the stars are generally brighter at these wavelengths and so can be more easily and accurately observed; effects of binary companions, which are usually earlier type stars, are minimized; reddening is less, can be more easily determined, and is less liable to differing extinction laws than in the UBV system; line-blanketing problems are smaller; the range in (R — I)0 is probably less than in (B — V)0, and the importance of the colour term in the P-L-C relation thus reduced.Available R, I data for classical Cepheids are gathered from the literature, and the P-L, P-C, and P-L-C relations investigated. It is found that the preliminary relations represent the data to within ± 0.13 mag. in 〈MR〉 and ± 0.02 mag. in 〈R–I〉o.There is some indication that the intrinsic colours of EV Set, U Sgr, and S Nor are bluer than hitherto believed, conceivably due to circumstellar reddening.

Coravel Radial-Velocity Curves for Cepheids in the Large Magellanic Cloud

1984 ◽  
Vol 88 ◽  
pp. 375-380
Author(s):  
M. Imbert ◽  
J. Andersen ◽  
A. Ardeberg ◽  
C. Bardin ◽  
W. Benz ◽  
...  
Keyword(s):  
Comparative Study ◽  
Radial Velocity ◽  
Stellar Evolution ◽  
Large Magellanic Cloud ◽  
Magellanic Clouds ◽  
Independent Determination ◽  
Fundamental Information ◽  
The Galaxy ◽  
Cepheid Variables

Radii and luminosities for Cepheid variables provide fundamental information on stellar evolution. Such data, obtained by the Baade-Wesselink method, are available and have been used for a number of galactic Cepheids. It is of particular interest to obtain corresponding data for Cepheids in the Magellanic Clouds. Firstly, this allows a comparative study of stellar evolution between the Galaxy and the Magellanic Clouds. Secondly, it provides data for an independent determination of the distance to the Magellanic Clouds.Radial-velocity observations have been made for a total of around 20 Cepheid variables in both the LMC and the SMC. All measurements were made with the photoelectric scanner CORAVEL attached to the Cassegrain focus of the Danish 1.54-m telescope at European Southern Observatory, La Silla, Chile. Observations were made from January 1981 through October 1983. The accuracy of individual radial-velocity observations is of the order of 1 km s−1. The B magnitudes of the six Cepheids presented range from 13.0 to 15.5.

Distance moduli and structure of the Magellanic Clouds from near-infrared photometry of classical Cepheids

1987 ◽  
Vol 321 ◽  
pp. 162 ◽  
Author(s):  
Douglas L. Welch ◽  
Robert A. McLaren ◽  
Barry F. Madore ◽  
Christopher W. McAlary
Keyword(s):  
Near Infrared ◽  
Magellanic Clouds ◽  
Infrared Photometry ◽  
Classical Cepheids

Detection of Sectoral Modes in the Eclipsing Binary KIC 4851217

2017 ◽  
Vol 14 (S339) ◽  
pp. 295-298
Author(s):  
M. Fedurco ◽  
Š. Parimucha ◽  
P. Gajdoš
Keyword(s):  
Light Curve ◽  
Frequency Analysis ◽  
Secondary Component ◽  
Frequency Range ◽  
Eclipsing Binary ◽  
Quadrupole Mode ◽  
Linear Coupling ◽  
Orbital Frequency ◽  
Short Period ◽  
Low Amplitude

AbstractKIC 4851217 is a short period eclipsing binary (P = 2.47 days) in the field of the Kepler K1 mission. As well as variability caused by the eclipses, low-amplitude pulsations are also present in the data. A frequency analysis of the residual light-curve revealed δ Sct pulsations in the frequency range from 15–21 d−1 with amplitudes up to 3.5 mmag. Strong linear coupling (fi = fp + kforb) to orbital frequency was found, indicating tidally locked modes. From an analysis of 5 selected groups of frequencies we identified a radial mode on the secondary component, 3 dipole modes (l = |m| = 1), one of them present on the secondary component, and a quadrupole mode (l = |m| = 2), also located on the secondary component.

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