2004A&A...426..279P


C.D.S. - SIMBAD4 rel 1.7 - 2020.01.25CET16:22:46

2004A&A...426..279P - Astronomy and Astrophysics, volume 426, 279-296 (2004/10-4)

Unveiling Mira stars behind the molecules. Confirmation of the molecular layer model with narrow band near-infrared interferometry.

PERRIN G., RIDGWAY S.T., MENNESSON B., COTTON W.D., WOILLEZ J., VERHOELST T., SCHULLER P., COUDE DU FORESTO V., TRAUB W.A., MILLAN-GABET R. and LACASSE M.G.

Abstract (from CDS):

We have observed Mira stars with the FLUOR beamcombiner on the IOTA interferometer in narrow bands around 2.2µm wavelength. We find systematically larger diameters in bands contaminated by water vapor and CO. The visibility measurements can be interpreted with a model comprising a photosphere surrounded by a thin spherical molecular layer. The high quality of the fits we obtain demonstrates that this simple model accounts for most of the star's spatial structure. For each star and each period we were able to derive the radius and temperature of the star and of the molecular layer as well as the optical depth of the layer in absorption and continuum bands. The typical radius of the molecular layer is 2.2R* with a temperature ranging between 1500 and 2100K. The photospheric temperatures we find are in agreement with spectral types of Mira stars. Our photospheric diameters are found smaller than in previous studies by several tens of percent. We believe previous diameters were biased by the use of unsuited geometrical models to explain visibilities. The conclusions of this work are various. First, we offer a consistent view of Mira stars over a wide range of wavelengths. Second, the parameters of the molecular layer we find are consistent with spectroscopic studies. Third, from our diameter measurements we deduce that all Mira stars are fundamental mode pulsators and that previous studies leading to the conclusion of the first-overtone mode were biased by too large diameter estimates.

Abstract Copyright:

Journal keyword(s): techniques: interferometric - stars: AGB and post-AGB - stars: fundamental parameters - stars: mass-loss - infrared: stars

Simbad objects: 22

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Number of rows : 22

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 * bet And PM* 01 09 43.92388 +35 37 14.0075 5.58 3.62 2.05 0.81 -0.19 M0+IIIa 531 0
2 * ups Per PM* 01 37 59.5569926 +48 37 41.569533 6.29 4.85 3.57 2.61 1.96 K3-IIICN0.5 215 0
3 * omi Cet Mi* 02 19 20.79210 -02 58 39.4956   7.63 6.53 5.03   M5-9IIIe+DA 1420 0
4 V* R Tri Mi* 02 37 02.3410168270 +34 15 51.365559405   8.524 7.306     M3.5-8e 179 0
5 * alf Cet LP? 03 02 16.77307 +04 05 23.0596 6.10 4.17 2.53 1.18 0.02 M1.5IIIa 438 0
6 V* U Ori Mi* 05 55 49.1689920441 +20 10 30.690374867 6.82 6.39 5.40     M6-9.5e 470 0
7 * eta Gem RG* 06 14 52.6452865329 +22 30 24.434377815 6.55 4.89 3.28 1.79 0.48 M2IIIa 240 0
8 * mu. Gem LP* 06 22 57.62686 +22 30 48.8979 6.37 4.51 2.87 1.30 -0.08 M3IIIab 363 1
9 * eps Gem V* 06 43 55.9262590 +25 07 52.051484 5.85 4.39 2.98 2.01 1.40 G8Ib 378 0
10 * alf CMi SB* 07 39 18.11950 +05 13 29.9552 0.82 0.79 0.37 -0.05 -0.28 F5IV-V+DQZ 1748 0
11 * bet Gem PM* 07 45 18.94987 +28 01 34.3160 3.00 2.14 1.14 0.39 -0.11 K0IIIb 1042 1
12 * alf Hya * 09 27 35.24270 -08 39 30.9583 5.14 3.42 1.97 0.93 0.16 K3IIIa 404 0
13 V* R Leo Mi* 09 47 33.4839808805 +11 25 43.823283729 9.22 8.94 7.53 3.39 0.12 M7-9e 866 1
14 V* EK Boo LP? 14 46 05.94566 +15 07 54.4332 8.51 7.20 5.63     M5III 73 0
15 * alf Ser PM* 15 44 16.0743159 +06 25 32.263272 5.080 3.800 2.630 1.82 1.25 K2IIIbCN1 490 0
16 * del Oph PM* 16 14 20.73853 -03 41 39.5612 6.30 4.34 2.75 1.46 0.43 M0.5III 343 0
17 * alf Vul PM* 19 28 42.3299553 +24 39 53.652455 7.77 5.95 4.45 3.24 2.27 M0.5IIIb 170 0
18 * del Sge SB* 19 47 23.2665287783 +18 32 03.520263112 6.20 5.23 3.82 2.37 1.08 M2II+B0V 191 0
19 * chi Cyg S* 19 50 33.9243904 +32 54 50.609683 7.02 6.06 4.24 1.81 -0.01 S6-9/1-2e 661 0
20 * eps Cyg ** 20 46 12.6823609 +33 58 12.924926 4.370 3.520 2.480 1.73 1.19 K0III 478 1
21 V* T Cep Mi* 21 09 31.7832206157 +68 29 27.190142015 9.15 8.82 7.33     M6-9e 362 0
22 * 5 Lac s*r 22 29 31.8225058 +47 42 24.792707 7.15 6.05 4.37 2.98 1.91 K9Ia+B2V 128 0

    Equat.    Gal    SGal    Ecl

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2020.01.25-16:22:46

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