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See detail2009: A Colliding-Wind Odyssey
Fahed, R.; Moffat, A. F. J.; Zorec, J. et al

in Astronomical Society of the Pacific Conference Series (2013, January 01)

We present the results from two optical spectroscopic campaigns on colliding-wind binaries (CWB) which both occurred in 2009. The first one was on WR 140 (WC7pd + O5.5fc), the archetype of CWB, which ... [more ▼]

We present the results from two optical spectroscopic campaigns on colliding-wind binaries (CWB) which both occurred in 2009. The first one was on WR 140 (WC7pd + O5.5fc), the archetype of CWB, which experienced periastron passage of its highly elliptical 8-year orbit in January. The WR 140 campaign consisted of a unique and constructive collaboration between amateur and professional astronomers and took place at half a dozen locations, including Teide Observatory, Observatoire de Haute Provence, Dominion Astrophysical Observatory, Observatoire du Mont-Mégantic and at several small private observatories. The second campaign was on a selection of 5 short-period WR + O binaries not yet studied for colliding-wind effects: WR 12 (WN8h), WR 21 (WN5o + O7 V), WR 30 (WC6 + O7.5 V), WR 31 (WN4o + O8), and WR 47 (WN6o + O5). The campaign took place at Leoncito Observatory, Argentina, during 1 month. We provide updated values of most of these systems for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates and colliding wind geometry. [less ▲]

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See detailSpectroscopy of the archetype colliding-wind binary WR 140 during the 2009 January periastron passage
Fahed, R.; Moffat, A. F. J.; Zorec, J. et al

in Monthly Notices of the Royal Astronomical Society (2011), 418

We present the results from the spectroscopic monitoring of WR 140 (WC7pd + O5.5fc) during its latest periastron passage in 2009 January. The observational campaign consisted of a constructive ... [more ▼]

We present the results from the spectroscopic monitoring of WR 140 (WC7pd + O5.5fc) during its latest periastron passage in 2009 January. The observational campaign consisted of a constructive collaboration between amateur and professional astronomers. It took place at six locations, including Teide Observatory, Observatoire de Haute Provence, Dominion Astrophysical Observatory and Observatoire du Mont Mégantic. WR 140 is known as the archetype of colliding-wind binaries and it has a relatively long period (?8 yr) and high eccentricity (?0.9). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates and colliding-wind geometry. [less ▲]

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See detailThe WR 140 periastron passage 2009: first results from MONS and other optical sources
Fahed, R.; Moffat, A. F. J.; Zorec, J. et al

in Eversberg, Thomas; Knapen, Johan (Eds.) Stellar Winds in Interaction (2011, January 01)

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in January 2009. This object is known as the archetype of colliding wind binaries and has a ... [more ▼]

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in January 2009. This object is known as the archetype of colliding wind binaries and has a relatively large period (~ 8 years) and eccentricity (~ 0.89). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates. [less ▲]

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See detailSpectroscopic follow-up of the colliding-wind binary WR140 during the 2009 January periastron passage
Fahed, R.; Moffat, A. F. J.; Zorec, J. et al

in Bulletin de la Societe Royale des Sciences de Liege (2011), 80

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in January 2009. This object is known as the archetype of colliding wind binaries and has a ... [more ▼]

We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in January 2009. This object is known as the archetype of colliding wind binaries and has a relatively large period (≃8 years) and eccentricity (≃0.9). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates. [less ▲]

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See detailThe Mons campaign on OB stars
Morel, Thierry ULg; Rauw, Grégor ULg; Eversberg, T. et al

in Bulletin de la Société Royale des Sciences de Liège (2011), 80

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See detailLong-term photometry of Variables I. (Manfroid+ 1991)
Manfroid, Jean ULg; Sterken, C.; Bruch, A. et al

Report (1995)

This is the first catalogue of photometric data in the Stroemgren system obtained during the period October 1982 - September 1986. Full description can be found in ESO report SP 8. Since our goal is not ... [more ▼]

This is the first catalogue of photometric data in the Stroemgren system obtained during the period October 1982 - September 1986. Full description can be found in ESO report SP 8. Since our goal is not absolute (all-sky) photometry, the observations should be used for differential photometry only. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 5 of paper) ------------------------------------ System y b-y m1 c1 ------------------------------------ 1 0.0109 0.0088 0.0133 0.0136 4 0.0068 0.0057 0.0079 0.0118 5 0.0087 0.0070 0.0114 0.0114 6 0.0090 0.0078 0.0126 0.0132 7 0.0071 0.0033 0.0041 0.0065 ------------------------------------ (2 data files). [less ▲]

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See detailHD160529: a new galactic Luminous Blue Variable
Stahl, O.; Sterken, C.; Gosset, Eric ULg et al

(1992)

Not Available

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See detailHD160529 - a New Galactic Luminous Blue Variable
Sterken, C.; Gosset, Eric ULg; Juttner, A. et al

in Astronomy and Astrophysics (1991), 247

The galactic early-type A hypergiant HD 160529 has been photometrically monitored in the Strömgren system during the past 18 years. HD 160529 has become fainter in the optical range by 0.5 mag during the ... [more ▼]

The galactic early-type A hypergiant HD 160529 has been photometrically monitored in the Strömgren system during the past 18 years. HD 160529 has become fainter in the optical range by 0.5 mag during the past eight years. In addition, pulsation-like variations with a quasi-period of 57 days and with a peak-to-peak amplitude of about 0.1 mag in b and y were found. The fading was not completely monotonous a fall of at least 0.2 mag in b and y within about 40 days around JD2446500 is particularly remarkable. This jump is accompanied by a change in the temperature-sensitive c[SUB]1[/SUB] index of about -0.14 mag. HD 160529 has become visually fainter and hotter during the past eight years, thus becoming a new case of a galactic Luminous Blue Variable (LBV). Model calculations on the basis of the photometry and previously published as well as new spectroscopic observations have shown HD 160529 to be a close counterpart of R 110, a recently discovered LBV in the LMC. From this comparison an absolute magnitude of M[SUB]V[/SUB] = -8.9 and a distance of 2.5 kpc is derived. The stellar parameters characterising the maximum state are estimated to be T[SUB]eff[/SUB] ≍ 8000 K, log g ≍ 0.55, R ≍ 330 R[SUB]sun[/SUB], from which the mass is estimated to be only M ≍ 13 M[SUB]sun[/SUB]. From the Hα profile a lower limit of the mass-loss rate of HD 160529 was calculated, which is about 10 times higher than that of R 110; this could be a consequence of the higher metallicity of the galactic LBV. The low mass of HD 160529 makes this luminous blue star a good candidate for a post-RSG (red supergiant phase) object, providing some evidence that (as sometimes argued) low metallicity is not a necessary prerequisite for evolution of massive stars backward to higher temperatures. [less ▲]

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See detailLong-term photometry of variables at ESO. I - The first data catalogue (1982-1986)
Manfroid, Jean ULg; Sterken, C.; Bruch, A. et al

in Astronomy and Astrophysics. Supplement Series (1991), 87

This paper presents the catalog of photometric data in the Stromgren system obtained during the first four years (October 1982 - September 1986) of the Long-Term Photometry of Variables (LTPV) program at ... [more ▼]

This paper presents the catalog of photometric data in the Stromgren system obtained during the first four years (October 1982 - September 1986) of the Long-Term Photometry of Variables (LTPV) program at ESO. The data are available in computer-readable form. [less ▲]

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See detailLong-Term Photometry of Variables at ESO. I.
Manfroid, Jean ULg; Sterken, C.; Bruch, A. et al

Report (1991)

Not Available

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See detailLong-term photometric campaign at ESO and the new eclipsing P Cygni star R 81 in the LMC
Wolf, B.; Sterken, C.; Stahl, O. et al

in The Messenger (1987), 47

The Long-term Photometry of Variables project is described. All measurements were carried out in the Stromgren uvby system and preference was given to differential measurements with two comparison stars ... [more ▼]

The Long-term Photometry of Variables project is described. All measurements were carried out in the Stromgren uvby system and preference was given to differential measurements with two comparison stars. Included in this photometry program was the study of R 81, the counterpart of P Cyg in the LMC. A variation period of 74.59 + or - 0.01 days was obtained for this eclipsing binary. [less ▲]

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See detailThe eclipsing variable HR 2800
Sterken, C.; Hensberge, H.; Vander Linden, D. et al

in Astronomy and Astrophysics. Supplement Series (1985), 60

The eclipsing variable star HR 2800 (HD 57593) is characterized on the basis of uvby photoelectric photometry and 20-A/mm coude spectrograph plates obtained at ESO and at SAOO during the period 1975-1983 ... [more ▼]

The eclipsing variable star HR 2800 (HD 57593) is characterized on the basis of uvby photoelectric photometry and 20-A/mm coude spectrograph plates obtained at ESO and at SAOO during the period 1975-1983. The data are presented graphically and used to estimate the ephemeris parameters of the eclipses, which have a depth in V of 0.25 mag, as time of minimum = JD 2,444,629.7797 + or - 0.010 and period = 24.6033 + or - 0.0003 days. HR 2800 is classified as a bright B-star Algol-type variable. [less ▲]

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