Multimode Cepheids in the Large Magellanic Cloud - challenges for theory
نویسنده
چکیده
Data on multimode Cepheids from OGLE-III catalog of the LMC Cepheids are confronted with results from model calculations. Models whose radial mode periods are consistent with observation are not always in agreement with published evolutionary models. Nonradial mode interpretation is considered for the cases of unusual period ratios. The greatest challenge for stellar pulsation theory is explanation of double-mode pulsators with period ratios near 0.6.
منابع مشابه
V(RI)C Photometry of Cepheids in the Magellanic Clouds
We present V(RI)C data for thirteen Cepheids in the Large Magellanic Cloud and eight in the Small Magellanic Cloud. The total number of new measures is fifty-five in each wavelength band. The median uncertainty in the photometry is ±0.03 mag. These results supplement a larger photometric program on Magellanic Cloud Cepheids previously published. Subject headings: Magellanic Clouds — Cepheids — ...
متن کاملOn the Enhancement of Mass Loss in Cepheids Due to Radial Pulsation. Ii. the Effect of Metallicity
It has been observed that Cepheids in the Magellanic Clouds have lower masses for the same luminosity than those in the Milky Way. The model, from Neilson & Lester (2008), of pulsation– driven mass loss for Cepheids is applied to theoretical models of Cepheids with metallicity consistent with the Milky Way and Large and Small Magellanic Clouds. The mass–loss model is analyzed using the metallic...
متن کاملUltra-low Amplitude Cepheids in the Large Magellanic Cloud
The MACHO variables of LMC Field 77 that lie in the vicinity of the Cepheid instability strip are reexamined. Among the 144 variables that we identify as Cepheids we find 14 that have Fourier amplitudes < 0.05 mag in the MACHO red band, of which 7 have an amplitude < 0.006mag : we dub the latter group of stars ultra-low amplitude (ULA) Cepheids. The variability of these objects is verified by a...
متن کاملThe distance modulus of the Small Magellanic Cloud based on double-mode Cepheids
We employ the very recent photometric data of the ogle project together with stellar atmosphere and linear pulsation models to determine the distance modulus of the Small Magellanic Cloud from its double-mode Cepheids. Based on the requirement of obtaining the same distance modulus DM from the two types of variables (fundamental & first overtone and first & second overtone), we get DM = 19.05 m...
متن کاملThe VMC Survey - X . Cepheids , RR Lyrae stars and binaries as probes of the Magellanic System ’ s structure ⋆
The VMC survey is obtaining multi-epoch photometry in the Ks band of the Magellanic System down to a limiting magnitude of Ks ∼ 19.3 for individual epoch data. The observations are spaced in time such as to provide optimal sampling of the light curves for RR Lyrae stars and for Cepheids with periods up to 20-30 days. We present examples of the Ks-band light curves of Classical Cepheids and RR L...
متن کامل