Query : 2000A&A...363..601A

2000A&A...363..601A - Astronomy and Astrophysics, volume 363, 601-604 (2000/11-2)

Nonlinear model pulsations for long-period Cepheids. II. Magellanic Cloud Cepheids.


Abstract (from CDS):

Nonlinear, radiative models for long-period Cepheids in the Magellanic Clouds were constructed and the theoretical light and velocity curves were compared with observations. We assumed a metal content Z=0.005, and two mass-luminosity M-L relations: one was obtained from stellar evolution calculation with convective overshooting models, and the other, which gives an even larger L for the same M, was suggested by the study of a bump Cepheid in the Magellanic Clouds. Both relations produce results which are in rough agreement with the observed light and radial velocity curves of Cepheids with period P>30d. The latter relation, however, gives better results when compared with observations for P∼10d. The longest P of stable limit cycle is about 130d; in a previous paper we obtained, for Z=0.020, a maximum P of about 70d. This result compares reasonably well with Cepheids observed in Galaxy and Magellanic Clouds; in other words, the longest P of Cepheids should depend on the average metallicity of the parent galaxy. The nonlinear P of more massive models with low metallicity tends to lengthen significantly for a very small increase of M, and this could explain the flattening of the PL relation for P>100d, which is observed in metal poor galaxies. A discussion of the shortcomings of the models for a period as short as about 10d and some comments on resonance effects are also reported.

Abstract Copyright:

Journal keyword(s): stars: variables: Cepheids - stars: variables: general - stars: oscillations - hydrodynamics - galaxies: Magellanic Clouds

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
1 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 10191 1
2 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 6276 1
3 SV* HV 905 cC* 05 09 15.9284230344 -68 44 29.529329028   15.06 14.520 13.99 13.592 ~ 29 0
4 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 15985 1

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