2016A&A...591A...8A


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.21CET05:43:21

2016A&A...591A...8A - Astronomy and Astrophysics, volume 591A, 8-8 (2016/7-1)

On the effect of rotation on populations of classical Cepheids. II. Pulsation analysis for metallicities 0.014, 0.006, and 0.002.

ANDERSON R.I., SAIO H., EKSTROM S., GEORGY C. and MEYNET G.

Abstract (from CDS):

Classical Cepheid variable stars (from hereon: Cepheids) are high-sensitivity probes of stellar evolution and fundamental tracers of cosmic distances. While rotational mixing significantly affects the evolution of Cepheid progenitors (intermediate-mass stars), the impact of the resulting changes in stellar structure and composition on Cepheids and their pulsational properties is hitherto unknown. Here we present the first detailed pulsational instability analysis of stellar evolution models that include the effects of rotation, for both fundamental mode and first overtone pulsation. We employ Geneva evolution models spanning a three-dimensional grid in mass (1.7-15M), metallicity (Z=0.014, 0.006, 0.002), and rotation (non-rotating, average & fast rotation). We determine (1) hot and cool instability strip (IS) boundaries taking into account the coupling between convection and pulsation; (2) pulsation periods; and (3) rates of period change. We investigate relations between period and (a) luminosity; (b) age; (c) radius; (d) temperature; (e) rate of period change; (f) mass; (g) the flux-weighted gravity-luminosity relation (FWGLR). We confront all predictions aside from those for age with observations, finding generally excellent agreement. We tabulate period-luminosity relations (PLRs) for several photometric pass-bands and investigate how the finite IS width, different IS crossings, metallicity, and rotation affect PLRs. We show that a Wesenheit index based on H, V, and I photometry is expected to have the smallest intrinsic PLR dispersion. We confirm that rotation resolves the Cepheid mass discrepancy. Period-age relations depend significantly on rotation, with rotation leading to older Cepheids, offering a straightforward explanation for evolved stars in binary systems that cannot be matched by conventional isochrones assuming a single age. We further show that Cepheids obey a tight FWGLR. Rotation is a fundamental property of stars that has important implications for the study of intermediate-mass stars, intermediate-age clusters, and classical Cepheid variable stars.

Abstract Copyright: © ESO, 2016

Journal keyword(s): stars: variables: Cepheids - supergiants - stars: oscillations - stars: evolution - stars: rotation - distance scale

Simbad objects: 14

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Number of rows : 14

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9112 1
2 V* BY Cas cC* 01 47 11.9193204766 +61 25 20.952299938   11.5 10.369     F5 111 0
3 V* SZ Cas cC* 02 27 13.7670524473 +59 27 38.174718163   11.5 9.60     G5III 152 0
4 * alf UMi cC* 02 31 49.09456 +89 15 50.7923 3.00 2.62 2.02 1.53 1.22 F8Ib 603 2
5 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5390 1
6 SV* HV 12024 cC* 05 23 07.71 -69 33 49.9   17.360 16.707   16.054 ~ 24 0
7 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14352 1
8 V* DX Gem cC* 06 33 54.6101670962 +14 28 17.011049441   11.24 10.73     ~ 85 0
9 V* AQ Pup cC* 07 58 22.0887170720 -29 07 48.335325928   9.70 8.54   7.175 F5-G2Ib 170 0
10 * 35 Cru cC* 12 31 40.3301092383 -59 25 26.122369782 6.60 6.19 5.53     F7Ib/II 122 0
11 HD 176155 cC* 18 58 14.7482217777 +17 21 39.295590199 6.61 6.18 5.38     F6Ib 337 0
12 HD 344787 * 19 43 29.3862130709 +23 10 40.635053293   10.33 9.32     K0 18 0
13 V* DT Cyg cC* 21 06 30.2442673195 +31 11 04.765587914 6.70 6.38 5.82     F7II- 289 0
14 NAME Galactic Bulge reg ~ ~           ~ 3248 0

    Equat.    Gal    SGal    Ecl

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2019.11.21-05:43:21

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