aiying zhou 周 爱 英 2010.03.31 beijing national astronomical observatories, cas —— several...
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Aiying ZHOU 周 爱 英
2010.03.31 Beijing
National Astronomical Observatories, CAS
—— Several Observational Aspects
Every star varies !
Light variations seems universal & much interesting
RRab
What are the Most Interesting Light Curves?
Orbital motion
Puls.
(A)
LC for the parent star of
CoRoT-exo-2b, 1.4RJ, 3.5MJ, 140d, ±0m.00016
78 transitsPorb =1d.74
Solar-like oscillation
Eclipsing Binaries with
Pulsating Components
Interests in such studies If no mechanism damping pulsations in close
binaries, percentage of pulsating stars expected among A-F components of detached & semi-detached eclipsing binaries should be at least the same as for single A-F type stars.
Pulsation characteristics of such systems are similar to those of single pulsators, but their evolutions are quite different due to mass accretion.
Advantages in such studies
Possibility of precise mass and radius determinations Possibility of mode identification during the eclipse o
rbital phases using the observed pulsational amplitude and phase changes (Nather & Robinson 1974, ApJ, 190, 637).
Precise estimation of the accretion rate using the pulsation period changes of the gainer/accreting star caused by accretion.
…… Ref.: 1. Aerts et al. 2004, ASP Conf. Ser. 318, 325
2. Lampens P. 2006, ASP Conf. Ser. 349, 153
δScuti in an Algol-type binary (oEA): AB Cas
Orbital motion
Puls. (A)
The A-F spectral type, mass-accreting, main-sequence pulsating stars in semi-detached Algol-type eclipsing binary systems, i.e. oscillating EA (oEA)
They cataloged:
25 DCST-type oEA:
20 semidetached +4 detached +1 unclassified
90 semidetached + 71 detached + 36 from Hipparcos
in theδScuti region of H-R diagram.
25 +197
How many now ?
In summary, > 72, DSCT–type oEA
> 100, All kinds, oscillating E. B.
> 420, various binary/multiple stellar systems with Puls. Comp.
0
10
20
30
40
50
60
70O A0
A1
A2
A3
A4
A5
A6-
9
B1-
4
B5-
7
B8
B9
F0
F1-
4
F5-
7
F8-
9 G K M
Interesting works
How can binarity modify the pulsational properties? In what manner?
How can binarity/multiplicity help to identify the pulsation modes?
Search for pulsating M,K giants and subgaint stars in E. B.
Search for extra-solar planets around a pulsator. Search for extragalactic E. B. with Puls. Comp. Search for RR in E. B.
Summary
Why
Statistics
Furture works
This talk is based on
Zhou A.-Y., 2010, arXiv:1002.2729 (to be updated)