2014A&A...563L...4N


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.22CEST04:36:24

2014A&A...563L...4N - Astronomy and Astrophysics, volume 563, L4-4 (2014/3-1)

Convection, granulation, and period jitter in classical Cepheids.

NEILSON H.R. and IGNACE R.

Abstract (from CDS):

Analyses of recent observations of the sole classical Cepheid in the Kepler field, V1154 Cygni, found random changes of about 30-min in the pulsation period. These period changes challenge standard theories of pulsation and evolution because the period change is non-secular, and explaining this period jitter is necessary for understanding stellar evolution and the role of Cepheids as precise standard candles. We suggest that convection and convective hot spots can explain the observed period jitter. Convective hot spots alter the timing of flux maximum and minimum in the Cepheid light curve, hence change the measured pulsation period. We present a model of random hot spots that generate a localized flux excess that perturbs the Cepheid light curve and consequently the pulsation period, which is consistent with the observed jitter. This result demonstrates how important understanding convection is for modeling Cepheid stellar structure and evolution, how convection determines the red edge of the instability strip, and just how sensitive Cepheid light curves are to atmospheric physics.

Abstract Copyright:

Journal keyword(s): convection - stars: late-type - starspots - stars: variables: Cepheids - stars: individual: V1154 Cyg

Simbad objects: 7

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Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 * alf UMi cC* 02 31 49.09456 +89 15 50.7923 3.00 2.62 2.02 1.53 1.22 F8Ib 601 2
2 * alf Ori s*r 05 55 10.30536 +07 24 25.4304 4.38 2.27 0.42 -1.17 -2.45 M1-M2Ia-Iab 1443 0
3 V* RS Pup cC* 08 13 04.2157137938 -34 34 42.691837063 8.89 8.00 6.70   5.453 F8Iab 309 1
4 * l Car cC* 09 45 14.8112246 -62 30 28.451894   4.33 3.40     G5Iab/b 277 1
5 HD 176155 cC* 18 58 14.7482217777 +17 21 39.295590199 6.61 6.18 5.38     F6Ib 337 0
6 V* V1154 Cyg Ce* 19 48 15.4663192383 +43 07 36.959329251   9.92 9.14   8.120 G0 75 0
7 * del Cep cC* 22 29 10.2650184 +58 24 54.713856 4.71 4.35 3.75   3.219 F5Iab:+B7-8 669 0

    Equat.    Gal    SGal    Ecl

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2019.10.22-04:36:24

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