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g Doradus stars in the SIAMOIS context
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Transcript of g Doradus stars in the SIAMOIS context
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Doradus stars in the SIAMOIS context
Philippe Mathias
Observatoire de la Côte d’Azur
Dept. GEMINI
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Generalities
► A7 -- F5 ► V -- IV► g-mode pulsators► ~60 confirmed variables► Periods: 0.3 -- 3 days► Multiperiodic► Flux-blocking mechanism► 50% in binary system► Solar metallicity
Fekel et al. 2005
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Large variety of spectra
• OHP survey:
Mathias et al. 2004
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g-modes: tangential motions
Kaye et al. 1999
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LPV detection
v.sin i = 46 km/s
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RV variations
• HD 209295
De Cat et al. 2006
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Typical amplitudes
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Composite spectra: ~ 10%
Fekel et al. 2003 HD 7169
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50% in a binary system
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Tidal excitations/ hybrids ?
Warner et al. 2003
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Multi-site survey of HD 211699
OHP+KPNO
v.sini=12km/s
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Fourier analysis
Hipparcos:f = 0.933 /d
2 others:
1.23 /d1.46 /d
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Complementary observations:interferometry
• Ex: HD 147787
• P = 39 d
• e=0.59
• M1/M2 ~ 1
• min ~ 12.3 mas
well resolved by the VLTI
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(u,v) plane coverage (ATs)
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SIAMOIS targets
• Visibility > 3 months from DOME C
• Moderate v.sin i
(< 20 km/s)• V < 5
27290 4.2 F4 III 55 bf
27377 7.4 F0 V 5.5 c / SB2
55892 4.5 F0 IV 51 bf
103257 6.7 F2 V c
110606 7.9 F2 V 5.8 c / SB2
137785 6.4 F2 V c
147787 5.3 F4 IV 7.6 c / SB2
149989 6.3 A9 V 134 bf
187028 7.5 F0 V 85 bf
197541 7.5 F0 V 29 c
206481 7.9 F0 V c
209295 7.3 F0 V 86 bf / SB / hy
216910 6.7 F2 IV 92 bf
224288 8.0 F0 V
Fortuntately,non exhaustive list!