J/A+A/614/A12       VLTI/PIONIER observations of CE Tauri     (Montarges+, 2018)

The convective photosphere of the red supergiant CE Tauri. I. VLTI/PIONIER H band interferometric imaging. Montarges M., Norris R., Chiavassa A., Tessore B., Lebre A., Baron F. <Astron. Astrophys. 614, A12 (2018)> =2018A&A...614A..12M 2018A&A...614A..12M (SIMBAD/NED BibCode)
ADC_Keywords: Interferometry ; Stars, supergiant ; Stars, M-type ; Stars, late-type Keywords: stars: individual: CE Tau - stars: imaging - supergiants - stars: mass-loss - infrared: Stars - techniques: interferometric Abstract: Red supergiant stars represent one of the latest stages of the evolution of massive stars. Their photospheric convection may play an important role in the launching mechanism of their mass loss. Yet, its characteristics and dynamics are poorly constrained. By observing red supergiant stars with near infrared interferometry at different epochs, we expect to unveil the evolution of bright convective features on their stellar surface. We observed the M2Iab-Ib red supergiant star CE Tau with the VLTI/PIONIER instrument in the H band at two different epochs separated by one month. We derive the angular diameter of the star, basic stellar parameters and reconstruct two reliable images of its H band photosphere. The contrast of the convective pattern of the reconstructed images is 5±1% and 6±1 % for our two epochs of observation. The stellar photosphere shows few changes between the two epochs. The contrast of the convective pattern is below the average contrast variations obtained on 30 randomly chosen snapshots of the best matching 3D radiative hydrodynamics simulation: 23±1% for the original simulation images, and 16±1% for the maps degraded to the reconstruction resolution. We offer two hypotheses to explain this observation: CE Tau may be experiencing a quiet convective activity episode or it could be a consequence of its warmer effective temperature (hence its smaller radius) compared to the simulation. Description: Reconstructed images obtained with the SQUEEZE algorithm on the red supergiant star CE Tauri from VLTI/PIONIER observations and derived basic stellar parameters Objects: -------------------------------------------------- RA (2000) DE Designation(s) -------------------------------------------------- 05 32 12.75 +18 35 39.2 CE Tau = * 119 Tau -------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file stel_par.dat 107 2 Stellar parameters compiled from Sect. 4.1.2 of the article list.dat 97 4 List of fits images fits/* . 4 Individual fits images -------------------------------------------------------------------------------- Byte-by-byte Description of file: stel_par.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 A6 --- Name Name of the star 8- 10 A3 --- Month Month of observation 12- 15 I4 --- Year Year of observation 17- 19 I3 Rsun Radius Stellar radius 21- 22 I2 Rsun e_Radius Error on the stellar radius 24- 30 E7.2 W/m2 Fbol Bolometric flux 32- 39 E8.2 W/m2 e_Fbol Error on the bolometric flux 41- 44 I4 K Teff Effective temperature 46- 48 I3 K e_Teff Error on the effective temperature 50- 53 F4.2 [Lsun] logL Luminosity 55- 58 F4.2 [Lsun] e_logL Lower error on the luminosity 60- 63 F4.2 [Lsun] E_logL Upper error on the luminosity 65- 69 F5.2 Msun Mcur Current mass 71- 74 F4.2 Msun e_Mcur Lower error on the current mass 76- 79 F4.2 Msun E_Mcur Upper error on the current mass 81- 84 F4.2 [cm/s2] logg Effective gravity 86- 89 F4.2 [cm/s2] e_logg Lower error on the effective gravity 91- 94 F4.2 [cm/s2] E_logg Upper error on the effective gravity 96- 99 F4.1 Myr Age Age of the star 101-103 F3.1 Myr e_Age Lower error on the age 105-107 F3.1 Myr E_Age Upper error on the age -------------------------------------------------------------------------------- Byte-by-byte Description of file: list.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 8 F8.5 deg RAdeg Right Ascension of center (J2000) 9- 17 F9.5 deg DEdeg Declination of center (J2000) 19- 20 I2 --- Nx Number of pixels along X-axis 22- 23 I2 --- Ny Number of pixels along Y-axis 25- 26 I2 Kibyte size Size of FITS file 28- 38 A11 --- FileName Name of FITS file, in subdirectory fits 40- 97 A58 --- Title Title of the FITS file -------------------------------------------------------------------------------- Acknowledgements: Miguel Montarges, miguel.montarges(at)obspm.fr
(End) Miguel Montarges [KU Leuven, Belgium], Patricia Vannier [CDS] 07-Feb-2018
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