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J/A+A/444/895       Spectroscopy of HD 45166                 (Steiner+, 2005)

The qWR star HD 45166: I. Observations and system parameters Steiner J.E., Oliveira, A.S. <Astron. Astrophys. 444, 895 (2005)> =2005A&A...444..895S
ADC_Keywords: Binaries, spectroscopic ; Stars, Wolf-Rayet ; Spectroscopy ; Equivalent widths ; Radial velocities Keywords: techniques: spectroscopic - binaries: spectroscopic - stars: Wolf-Rayet Abstract: The binary star HD 45166 has been observed since 1922 but its orbital period has not yet been found. It is considered a peculiar Wolf-Rayet star, and its assigned classification has varied. For this reason we included the object as a candidate V Sge star and performed spectroscopy in order to search for its putative orbital period. High-resolution spectroscopic observations show that the spectrum, in emission and in absorption, is quite rich. The emission lines have great diversity of widths and profiles. The full widths at half maximum vary from 70km/s for the weakest lines up to 370km/s for the most intense ones. The Hydrogen and Helium lines are systematically broader than the CNO lines. Assuming that HD 45166 is a double-line spectroscopic binary, it present s an orbital period of P=1.596±0.003-day, with an eccentricity of e=0.18±0.08. In addition, a search for periodicity using standard techniques reveals that the emission lines present at least two other periods, of 5 and 5 hour. The secondary star has a spectral type of B7 V and, therefore, should have a mass of about M=4.8M. Given the radial velocity amplitudes, we determined the mass of the hot (primary) star as M=4.2±0.7M and the inclination angle of the system, i=0.77±0.09deg. As the eccentricity of the orbit is non zero, the Roche lobes increase and decrease as a function of the orbital phase. At periastron, the secondary star fills its Roche lobe. The distance to the star has been re-determined as d=1.3±0.2kpc and a color excess of E(B-V)=0.155±0.007 has been derived. This implies an absolute B magnitude of -0.6 for the primary star and -0.7 for the B7 star. We suggest that the discrete absorption components (DACs) observed in the ultraviolet with a periodicity similar to the orbital period may be induced by periastron events. Description: Journal of observations of HD 45166 and its spectral lines identifications and measurements are presented. The spectra were obtained with the FEROS spectrograph and have high spectral resolution (R=48000) and covers from 3700 to 8800Å. The spectral measurements of each absorption and emission lines are the observed central wavelength, the radial velocity in the heliocentric system, the equivalent width and the FWHM. Objects: ------------------------------------------------ RA (2000) DE Designation(s) ------------------------------------------------ 06 26 19.2 +07 58 28 HD 45166 = BD+08 1332 ------------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 51 12 Journal of observations table3.dat 73 63 Strong absorption lines (Wlambda>0.02Å) table4.dat 73 27 Weak absorption lines (Wlambda<0.02Å) table5.dat 73 114 Emission lines
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 10 A10 "YYYY/MM/DD" Date Observation date (UT) 13- 21 A9 -- Tel Telescope 25- 27 F3.1 0.1nm Res Spectral resolution 30- 31 I2 min ExpTime Exposure time 34- 35 I2 -- Nexp Number of exposures 39- 42 I4 0.1nm Lambdamin Spectral coverage, lower value 43 A1 --- --- [-] 44- 47 I4 0.1nm Lambdamax Spectral coverage, upper value
Byte-by-byte Description of file: table[345].dat
Bytes Format Units Label Explanations
1- 7 F7.2 0.1nm Lambda Wavelength 8 A1 --- u_Lambda Uncertainty flag on Lambda 10- 14 F5.2 0.1nm Rest1 ? First rest wavelength 16- 19 F4.2 0.1nm Rest2 ? Second rest wavelength 21- 24 F4.2 0.1nm Rest3 ? Third rest wavelength 26- 29 F4.1 km/s HRV ?=- Heliocenttric radial velocity 30 A1 --- u_HRV Uncertainty flag on HRV 33- 39 F7.4 0.1nm EW ?=- Equivalent width 40 A1 --- u_EW Uncertainty flag on EW 43- 47 F5.1 km/s FWHM ?=- Line Full Width Half Maximum (only in tables 3 and 5) 48 A1 --- u_FWHM Uncertainty flag on FWHM 51- 73 A23 --- Id Line identification
Acknowledgements: Alexandre Oliveira, aoliveira(at)
(End) Alexandre Oliveira [SOAR Telescope], Patricia Vannier [CDS] 20-Oct-2005
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