2001A&A...376..460S


Query : 2001A&A...376..460S

2001A&A...376..460S - Astronomy and Astrophysics, volume 376, 460-475 (2001/9-3)

Multi-frequency variations of the Wolf-Rayet system HD 193793 (WC7pd+O4-5) III. IUE observations.

SETIA GUNAWAN D.Y.A., VAN DER HUCHT K.A., WILLIAMS P.M., HENRICHS H.F., KAPER L., STICKLAND D.J. and WAMSTEKER W.

Abstract (from CDS):

The colliding-wind binary system WR140 (HD 193793, WC7pd+O4-5, P=7.94yr) was monitored in the ultraviolet by IUE from 1979 to 1994 in 35 short-wavelength high-resolution spectra. An absorption-line radial-velocity solution is obtained from the photospheric lines of the O component, by comparison with a single O star. The resulting orbital parameters, e=0.87±0.05, ω=31°±9° and K_ Ostar_=25±15km/s, confirm the large eccentricity of the orbit, within the uncertainties of previous optical studies. This brings the weighted mean UV-optical eccentricity to e=0.85±0.04. Occultation of the O-star light by the WC wind and the WC+O colliding-wind region results into orbital modulation of the P-Cygni profiles of the CII, CIV and SiIV resonance lines. Near periastron passage, the absorption troughs of those resonance-line profiles increase abruptly in strength and width, followed by a gradual decrease. In particular, near periastron the blue black-edges of the P-Cygni absorption troughs shift to larger outflow velocities. We discuss that the apparently larger wind velocity and velocity dispersion observed at periastron could be explained by four phenomena: (i) geometrical resonance-line eclipse effects being the main cause of the observed UV spectral variability, enhanced by sightline crossing of the turbulent wind-wind collision zone; (ii) the possibility of an orbital-plane enhanced WC7 stellar wind; (iii) possible common-envelope acceleration by the combined WC and O stellar radiation fields; and (iv) possible enhanced radiatively driven mass loss due to tidal stresses, focused along the orbiting line of centers.

Abstract Copyright:

Journal keyword(s): stars: binaries: spectroscopic - stars: early-type - stars: Wolf-Rayet - stars: individual: WR 140 - stars: winds, outflows - ultraviolet: stars

Simbad objects: 23

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Number of rows : 23
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 HD 5980 WR* 00 59 26.5838833944 -72 09 53.927337312   11.13 11.31   11.029 WN4+O7I: 393 1
2 HD 15558 Y*O 02 32 42.5366901168 +61 27 21.572901360 7.82 8.37 7.87 7.34 6.94 O4.5III(f) 314 0
3 HD 269698 s*b 05 31 44.2080798984 -67 38 01.374839556 9.520 12.00 12.22 12.47 11.167 O4Ia 111 0
4 HD 269810 Em* 05 35 13.8977747136 -67 33 27.542449260   12.08 12.22 12.53   O3III(f*) 106 0
5 HD 46223 Y*O 06 32 09.3068103600 +04 49 24.705695568 6.73 7.50 7.28 6.95 6.79 O4V((f)) 381 0
6 * zet Pup BY* 08 03 35.04754 -40 00 11.3321 0.89 1.98 2.25 2.36 2.58 O4I(n)fp 1156 1
7 * gam02 Vel WR* 08 09 31.95013 -47 20 11.7108 0.64 1.58 1.83 1.85 2.00 WC8+O7.5III-V 907 0
8 HD 76536 WR* 08 54 59.1670918944 -47 35 32.662167792 9.04 9.13 8.80 9.52   WC 124 0
9 HD 90657 WR* 10 26 31.4087563344 -58 38 26.182481568 9.53 10.07 9.65 9.84   WN5+O4-6 161 0
10 * eta Car Em* 10 45 03.545808 -59 41 03.95124 6.37 7.03 6.48 6.123 4.41 LBV 2442 0
11 HD 96715 * 11 07 32.8167251952 -59 57 48.704400540 7.51 8.32 8.28 9.04   O4V((f))z 113 0
12 HD 97152 WR* 11 10 04.0797150120 -60 58 44.963276664 7.47 8.03 8.07 8.91   WC7+O7V 183 0
13 CPD-61 3569 WR* 13 18 01.0421567664 -62 26 04.755661116 12.66 12.64 11.88 11.84   WC7+OB 62 0
14 WR 56 WR* 13 33 45.3814542096 -64 07 31.276015824   12.75 14.00 13.60   WC6 39 0
15 WRAY 16-172 WR* 15 18 20.7584521536 -59 38 17.324150928 14.83 14.52 13.28 12.99   WC7 50 2
16 HD 152270 WR* 16 54 19.6991292072 -41 49 11.531710092 6.26 6.80 6.597 6.72 6.39 WC7+O5-8 303 0
17 HD 156385 WR* 17 19 29.9012420376 -45 38 23.874269568 6.55 6.97 6.92 8.11   WC7 164 0
18 * 9 Sgr Em* 18 03 52.4450051016 -24 21 38.632254012 5.08 5.97 5.97 5.72 5.70 O4V((f))z 543 0
19 HD 190429A s*b 20 03 29.395 +36 01 30.53   7.20 7.09     O4If 85 0
20 HD 192641 WR* 20 14 31.7666855880 +36 39 39.598210224 7.80 8.20 7.91     WC7pd+O9V 330 0
21 HD 193576 WR* 20 19 32.4229160448 +38 43 53.959035756 8.15 8.53 8.00     WN5+O6II-V 709 0
22 HD 193793 WR* 20 20 27.9757908696 +43 51 16.286840244 6.90 7.25 6.85 4.58   WC7pd+O5.5fc 713 0
23 HD 211853 WR* 22 18 45.6057566664 +56 07 33.898679364 8.84 9.534 9.236 9.108   WN6o+O6I 276 0

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