E. Alécian, C. Catala, M.J. Goupil RS Cha A binary system suitable for testing stellar physics modeling during the pre-main sequence phase. E. Alécian, C. Catala, M.J. Goupil LESIA - Observatoire de Paris-Meudon 2nd Corot-Brazil Workshop, Ubatuba 5 Nov. 2005

RS Cha : an PMS eclipsing SB2 system Evelyne Alécian RS Cha : an PMS eclipsing SB2 system Primary Secondary References M/M 1.89  0.01 1.87 0.01 Alécian et al. (2005) R/R 2.15  0.06 2.36  0.06 Teff (K) 7638  76 7228  72 Ribas et al. (2000) log(L/L) 1.15  0.09 1.13  0.09 [Fe/H] 0.17  0.01 P (day) 1.67 synchronized system i (°) 83.4  0.3 Clausen & Nordström (1980)

RS Cha : PMS Spectroscopic Binary Evelyne Alécian RS Cha : PMS Spectroscopic Binary CESAM

RS Cha : PMS Spectroscopic Binary Evelyne Alécian RS Cha : PMS Spectroscopic Binary CESAM

RS Cha : PMS Spectroscopic Binary Evelyne Alécian RS Cha : PMS Spectroscopic Binary Error boxes calculated from masses and radii CESAM

 Scuti type pulsations in RS Cha Evelyne Alécian  Scuti type pulsations in RS Cha Log(Teff) (K) Log(L/L) Palla & Stahler (2001) Andersen (1975) : primary  PMS  Scuti star Marconi & Palla (1998) : theoretical instability strip Palla & Stahler (2001) : secondary  PMS  Scuti star Alécian et al. (2005) : both are pulsating June 19-24 2005 Stellar Pulsation and Evolution

 Scuti type pulsations in both components Evelyne Alécian  Scuti type pulsations in both components Residuals = vobs - vcalc vcalc : velocity calculated from Clausen & Nordström (1980) ephemeris Primary Secondary Alécian et al. (2005)

 Scuti type pulsations in both components Alécian et al. (2005) Evelyne Alécian  Scuti type pulsations in both components Residuals Periodic variations Primary Secondary Alécian et al. (2005) Pulsation period ~ 1 h June 19-24 2005 Stellar Pulsation and Evolution

Theoretical modes pulsations Evelyne Alécian Theoretical modes pulsations Primary star, M = 1.89 M degree l Non-adiabatic calculations MAD (M.-A. Dupret)

Theoretical modes pulsations Evelyne Alécian Theoretical modes pulsations Secondary star, M = 1.87 M degree l Non-adiabatic calculations MAD (M. A. Dupret)

Perspectives Improving temperature determination : next step Evelyne Alécian Perspectives Improving temperature determination : next step Improving knowledge of pulsations : long term continuous multi-site monitoring of spectroscopic data

Evelyne Alécian Autres diapo

RS Cha : PMS Spectroscopic Binary Evelyne Alécian RS Cha : PMS Spectroscopic Binary June 19-24 2005 Stellar Pulsation and Evolution

RS Cha : PMS Spectroscopic Binary Evelyne Alécian RS Cha : PMS Spectroscopic Binary June 19-24 2005 Stellar Pulsation and Evolution

RS Cha : Observations Primary Secondary References M/M 1.89  0.01 Evelyne Alécian RS Cha : Observations Primary Secondary References M/M 1.89  0.01 1.87 0.01 Alécian et al. (2005) R/R 2.15  0.06 2.36  0.06 logTeff (K) 3.883  0.010 3.859  0.010 Ribas et al. (2000) log(L/L) 1.15  0.09 1.13  0.09 [Fe/H] 0.17  0.01 vsini (km/s) 64  6 70  6 i (°) 83.4  0.3 Clausen & Nordström (1980) June 19-24 2005 Stellar Pulsation and Evolution