2004A&A...418..675P


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.22CEST03:19:38

2004A&A...418..675P - Astronomy and Astrophysics, volume 418, 675-685 (2004/5-1)

Interferometric observations of the supergiant stars α Orionis and α Herculis with FLUOR at IOTA.

PERRIN G., RIDGWAY S.T., COUDE DU FORESTO V., MENNESSON B., TRAUB W.A. and LACASSE M.G.

Abstract (from CDS):

We report the observations in the K band of the red supergiant star α Orionis and of the bright giant star α Herculis with the FLUOR beamcombiner at the IOTA interferometer. The high quality of the data allows us to estimate limb-darkening and derive precise diameters in the K band which combined with bolometric fluxes yield effective temperatures. In the case of Betelgeuse, data collected at high spatial frequency although sparse are compatible with circular symmetry and there is no clear evidence for departure from circular symmetry. We have combined the K band data with interferometric measurements in the L band and at 11.15µm. The full set of data can be explained if a 2055K layer with optical depths τK=0.060±0.003, τL=0.026±0.002 and τ11.15µm=2.33±0.23 is added 0.33R* above the photosphere providing a first consistent view of the star in this range of wavelengths. This layer provides a consistent explanation for at least three otherwise puzzling observations: the wavelength variation of apparent diameter, the dramatic difference in limb darkening between the two supergiant stars, and the previously noted reduced effective temperature of supergiants with respect to giants of the same spectral type. Each of these may be simply understood as an artifact due to not accounting for the presence of the upper layer in the data analysis. This consistent picture can be considered strong support for the presence of a sphere of warm water vapor, proposed by Tsuji (2000ApJ...538..801T) when interpreting the spectra of strong molecular lines.

Abstract Copyright:

Journal keyword(s): stars: supergiants - infrared: stars - techniques: interferometric

Simbad objects: 10

goto Full paper

goto View the reference in ADS

Number of rows : 10

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 * alf Cet LP? 03 02 16.77307 +04 05 23.0596 6.10 4.17 2.53 1.18 0.02 M1.5IIIa 437 0
2 * alf Ori s*r 05 55 10.30536 +07 24 25.4304 4.38 2.27 0.42 -1.17 -2.45 M1-M2Ia-Iab 1443 0
3 * eta Gem RG* 06 14 52.6452865329 +22 30 24.434377815 6.55 4.89 3.28 1.79 0.48 M2IIIa 240 0
4 * mu. Gem LP* 06 22 57.62686 +22 30 48.8979 6.37 4.51 2.87 1.30 -0.08 M3IIIab 362 1
5 * mu. CMa ** 06 56 06.64589 -14 02 36.3520           K3II+B8.5 51 0
6 * alf CMi SB* 07 39 18.11950 +05 13 29.9552 0.82 0.79 0.37 -0.05 -0.28 F5IV-V+DQZ 1740 0
7 * 56 Leo LP? 10 56 01.4689991 +06 11 07.327524 8.45 7.24 5.78 3.53 1.44 M5.5III: 159 0
8 V* EK Boo LP? 14 46 05.94566 +15 07 54.4332 8.51 7.20 5.63     M5III 72 0
9 * alf Her ** 17 14 38.85818 +14 23 25.2262   4.51 3.06     M5Ib-II+G5III+F2V: 185 0
10 * gam Aql * 19 46 15.5802908 +10 36 47.740788 5.93 4.23 2.72 1.65 0.87 K3II 416 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2004A&A...418..675P and select 'bookmark this link' or equivalent in the popup menu


2019.10.22-03:19:38

© Université de Strasbourg/CNRS

    • Contact