2015A&A...579A..81J


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.10CEST01:42:05

2015A&A...579A..81J - Astronomy and Astrophysics, volume 579A, 81-81 (2015/7-1)

The peculiar fast-rotating star 51 Ophiuchi probed by VEGA/CHARA.

JAMIALAHMADI N., BERIO P., MEILLAND A., PERRAUT K., MOURARD D., LOPEZ B., STEE P., NARDETTO N., PICHON B., CLAUSSE J.M., SPANG A., McALISTER H., TEN BRUMMELAAR T., STURMANN J., STURMANN L., TURNER N., FARRINGTON C., VARGAS N. and SCOTT N.

Abstract (from CDS):

Stellar rotation is a key in our understanding of both mass-loss and evolution of intermediate and massive stars. It can lead to anisotropic mass-loss in the form of radiative wind or an excretion disk. We wished to spatially resolve the photosphere and gaseous environment of 51 Oph, a peculiar star with a very high vsini of 267km/s and an evolutionary status that remains unsettled. It has been classified by different authors as a Herbig, a β Pic, or a classical Be star. We used the VEGA visible beam combiner installed on the CHARA array that reaches a submilliarcsecond resolution. Observation were centered on the Hα emission line. We derived, for the first time, the extension and flattening of 51 Oph photosphere. We found a major axis of θeq=8.08±0.70R and a minor axis of θpol=5.66±0.23R. This high photosphere distortion shows that the star is rotating close to its critical velocity. Finally, using spectro-interferometric measurements in the H α line, we constrained the circumstellar environment geometry and kinematics and showed that the emission is produced in a 5.2±2R* disk in Keplerian rotation. From the visible point of view, 51 Oph presents all the features of a classical Be star: near critical-rotation and double-peaked Hα line in emission produced in a gaseous disk in Keplerian rotation. However, this does not explain the presence of dust as seen in the mid-infrared and millimeter spectra, and the evolutionary status of 51 Oph remains unsettled.

Abstract Copyright:

Journal keyword(s): stars: emission-line, Be - stars: evolution - stars: rotation

Simbad objects: 9

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Number of rows : 9

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 * alf Eri Be* 01 37 42.84548 -57 14 12.3101 -0.36 0.30 0.46 0.49 0.60 B6Vpe 445 0
2 * alf Leo PM* 10 08 22.31099 +11 58 01.9516 0.88 1.24 1.40 1.37 1.47 B8IVn 807 1
3 HD 150366 PM* 16 41 36.1776364020 -24 28 04.660318849   6.29 6.09     A7III 57 0
4 * c Oph Be* 17 31 24.9541340 -23 57 45.513592 4.75 4.81 4.81 4.74 4.72 A0V 254 0
5 * alf Oph ** 17 34 56.06945 +12 33 36.1346 2.32 2.22 2.07 1.93 1.85 A5IVnn 441 0
6 * 4 Sgr PM* 17 59 47.5513229478 -23 48 58.026944408   4.698 4.724     A0 84 0
7 * gam Sct * 18 29 11.8538827 -14 33 56.931865   4.739 4.675     A1IV/V 103 0
8 * alf Aql dS* 19 50 46.99855 +08 52 05.9563 1.07 0.98 0.76 0.62 0.49 A7Vn 819 0
9 * alf Cep PM* 21 18 34.77233 +62 35 08.0681 2.770 2.680 2.460 2.22 2.11 A8Vn 340 0

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2020.07.10-01:42:05

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