Diapositive 1

1
Solar-like oscillations in Red Giants Status
Perspectives with SIAMOIS Caroline
Barban LESIA/UFE Observatoire de Paris
2
http//www.bramboroson.com/astro/images/hrdiagram.
jpg
Red giant solar-like oscillations Amplitude gt 10
ppm or m/s Period gt hours Few modes (10s) Only
radial modes (?)
3
Solar-like oscillations detections
Red giants
4
Solar-like oscillations in red giants
Setiawan et al. 2005
Buzasi et al. 2000
? UMa, K0III
http//homepage.smc.edu/balm_simon/images/astro20
1a/post_ms_low_mass/red_giant.gif
0
50
0
frequency (?Hz)
5000
? Hya, K3II-III
Arcturus, K1.5III
Retter et al. 2003
5
?? Hya (G7III,mv3.54)
CORALIE, over 1 month 433 Radial Velocity data
50 - 130 ?Hz A2 m/s
Autocorrelation
http//homepage.smc.edu/balm_simon/images/astro20
1a/post_ms_low_mass/red_giant.gif
lt??0gt 7 ?Hz
3.15 M?
3.07 M?
2.93 M?
Frandsen et al. 2002
6
Coralie/1.2m La silla, Chile
Solar-like oscillations in ? Oph, ? Ser
?
collaboration Belgique-Suisse-France
?
Elodie/1.93m OHP, France
http//homepage.smc.edu/balm_simon/images/astro20
1a/post_ms_low_mass/red_giant.gif
Over 74 nights, 635 RV data
7
? Ser (K0III,mv3.26)
Over 74 nights, 1062 RV data
80 - 170 ?Hz A2 m/s lt??0gt 8 ?Hz
Autocorrelation
W1
???
2???
??
??-W1
Barban et al., SOGO 2004
8
? Oph (G9.5III,mv3.24)
30 - 90 ?Hz A3 m/s lt??0gt 5 or 7 ?Hz
Over 74 nights, 635 RV data
http//homepage.smc.edu/balm_simon/images/astro20
1a/post_ms_low_mass/red_giant.gif
OR
De Ridder et al. 2006
lt??0gt 7 ?Hz
lt??0gt 5 ?Hz
9
Red giant observations with MOST
10
? Oph (G9.5III,mv3.24)
window
duty cycle 50 28 days
Poribte
-Poribte
Poribte
- Poribte
S
-S
-SPoribte
SPoribt
11
? Oph (G9.5III,mv3.24)
Autocorrelation
lt??0gt 5 ?Hz
12
http//www.ifremer.fr/ifrtp/img/cartes/antarc.jpg
Red giant observations with SIAMOIS from DOME C
http//www.gdargaud.net/Photo/Panorama.html
13
Possible targets with Siamois
14
Siamois red giant simulation
window
Dome C, 90 days duty cycle 86
window
1 ideal site, 90 days 8h/night duty cycle 33
15
Siamois red giant simulation
Dome C, 90 days duty cycle 86
Autocorrelation
1 ideal site, 90 days 8h/night duty cycle 33
W1
16
Hydrodynamical simulation (B. Freytag)
Why observing red giants
(L/M)1.5
(L/M)0.8
(L/M)1.0
(L/M)0.7
Vmax/Vmax ?
Samadi et al. 2005