Solar-like oscillations in Red Giants: Status & Perspectives with SIAMOIS Caroline Barban
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Transcript of Solar-like oscillations in Red Giants: Status & Perspectives with SIAMOIS Caroline Barban
Solar-like oscillations in Red
Giants:Status & Perspectives
with SIAMOIS
Caroline BarbanLESIA/UFE
Observatoire de Paris
2
http://www.bramboroson.com/astro/images/hrdiagram.jpg
Red giant solar-like oscillations
Amplitude > 10 ppm or m/sPeriod > hours
Few modes (10’s)Only radial modes (?)
Solar-like oscillations detectionsRed giants
http
://h
omep
age.
smc.
edu/
balm
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on/im
ages
/ast
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201a
/pos
t_m
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w_m
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red_
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t.gi
f
Solar-like oscillations in red giants
UMa, K0III WIRE, 37 days 1.8 - 44 HzA~1-4 105 ppm
Hya, K3II-III
WIRE, 19 days4 - 7 Hz
A~1000 ppm
FEROS over 17 days 243 spectra50 - 120 Hz
<0>~8 HzArcturus, K1.5III
Buzasi et al. 2000Setiawan et al. 2005
Retter et al. 2003
0 5000frequency (Hz)
0 50
http
://h
omep
age.
smc.
edu/
balm
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on/im
ages
/ast
ro%
201a
/pos
t_m
s_lo
w_m
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red_
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t.gi
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Hya (G7III,mv=3.54)
50 - 130 HzA~2 m/s
CORALIE, over 1 month433 Radial Velocity data
Autocorrelation
<0> ~ 7 Hz
3.07 M
3.15 M
2.93 M
Frandsen et al. 2002
http
://h
omep
age.
smc.
edu/
balm
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on/im
ages
/ast
ro%
201a
/pos
t_m
s_lo
w_m
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red_
gian
t.gi
f
Coralie/1.2mLa silla, Chile
Elodie/1.93m OHP, France
collaboration Belgique-Suisse-France
Solar-like oscillations
in Oph, Ser
Over 74 nights, 635 RV data
Ser (K0III,mv=3.26)
80 - 170 HzA~2 m/s
<0> ~ 8 Hz
?-W1
2?W1
Barban et al., SOGO 2004
Over 74 nights, 1062 RV data
Autocorrelation
http
://h
omep
age.
smc.
edu/
balm
_sim
on/im
ages
/ast
ro%
201a
/pos
t_m
s_lo
w_m
ass/
red_
gian
t.gi
f Oph (G9.5III,mv=3.24)
Autocorrelation
W1
2W1-2 W1-
W1 -2-W1 3-W1
OR
Over 74 nights, 635 RV data
30 - 90 HzA~3 m/s
<0> ~ 5 or 7 Hz
<0> ~ 5 Hz
<0> ~ 7 Hz
De Ridder et al. 2006
Red giant observations
with MOST
Oph (G9.5III,mv=3.24)window
Poribte- Poribte
S-S -S+Poribte S+Poribt
-Poribte Poribte
duty cycle ~ 50%28 days
Autocorrelation
<0> ~ 5 Hz
Oph (G9.5III,mv=3.24)
Red giant observations with SIAMOISfrom DOME C
http://www.ifremer.fr/ifrtp/img/cartes/antarc.jpg
http://www.gdargaud.net/Photo/Panorama.html
Possible targets with Siamois
Siamois: red giant simulationwindow
window
Dome C, 90 daysduty cycle ~ 86 %
1 “ideal” site, 90 days8h/nightduty cycle ~ 33 %
Dome C, 90 daysduty cycle ~ 86 %
1 “ideal” site, 90 days8h/nightduty cycle ~ 33 %
Siamois: red giant simulation
Autocorrelation W1
Autocorrelation
<0> 2<0>
2
Why observing red giants
Hydrodynamical simulation (B. Freytag)
Samadi et al. 2005
Vm
ax/V
max
(L/M)1.5
(L/M)1.0
(L/M)0.8
(L/M)0.7