References of "Gosset, Eric"
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See detailWR 134 line-profile variability revisited
Vreux, Jean-Marie ULg; Gosset, Eric ULg; Bohannan, B. et al

in Astronomy and Astrophysics (1992), 256

Line profile variations of WR 134 are analyzed on more than 200 spectra collected at Haute Provence Observatory and at Kitt Peak National Observatory. No conclusive evidence is found for a periodic ... [more ▼]

Line profile variations of WR 134 are analyzed on more than 200 spectra collected at Haute Provence Observatory and at Kitt Peak National Observatory. No conclusive evidence is found for a periodic behavior. However, for some frequencies, for example, the ones close to nu = (n x 0.5)/d, the data are ill-distributed, and the existence of a related periodic phenomenon cannot be completely ruled out. This does not mean that the variability presents a purely random behavior. Several new characteristics of the observed deformations are extracted from the analysis of the spectra and it is tentatively suggested that these could be the signature of a bipolar flow. [less ▲]

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

(1992)

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See detailA photometric study of the bright cloud B in Sagittarius. VII - 1165 new variable stars and 65 diffuse objects
Terzan, A.; Gosset, Eric ULg

in Astronomy and Astrophysics. Supplement Series (1991), 90

A field in the Sagittarian bright cloud in the direction of the Galactic center is investigated by means of the B, V, and R Schmidt plates at the ESO, and 1165 variable stars are reported. The position, R ... [more ▼]

A field in the Sagittarian bright cloud in the direction of the Galactic center is investigated by means of the B, V, and R Schmidt plates at the ESO, and 1165 variable stars are reported. The position, R magnitudes, epochs, and amplitudes of variation are given for each star, and the surface density per square degree of variable stars increases from 1.7 to 65. The number of variables in the present field is similar to that for field A, and variables of type L and/or M are more densely numerous toward the center of the Galaxy than at other locations. Of the objects listed, 65 are given with potential classifications based on morphological data from the B and R Schmidt plates. The preliminary observations suggest a success rate of 42 percent on the precise prediction of the object types. [less ▲]

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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 detailWR 22 is an Eclipsing Binary Star
Gosset, Eric ULg; Remy, Marc; Manfroid, Jean ULg et al

in Information Bulletin on Variable Stars (1991), 3571

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See detailThe Liege GRISM search for quasars
Gosset, Eric ULg; Surdej, Jean ULg; Cheng, F. H. et al

in Crampton, David (Ed.) Proceedings of a workshop "The Space Distribution of Quasars", ASP Conference Series, Vol. 21 (1991)

We report on an on-going grism survey in which nine fields, one degree in diameter, have been searched for quasar-candidates. The selection techniques, the different calibrations, as well as the ... [more ▼]

We report on an on-going grism survey in which nine fields, one degree in diameter, have been searched for quasar-candidates. The selection techniques, the different calibrations, as well as the spectroscopic follow-up are briefly described. [less ▲]

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See detailAnalysis of the light variations of the Wolf-Rayet star WR16
Gosset, Eric ULg; Vreux, Jean-Marie ULg; Manfroid, Jean ULg et al

in Astronomy and Astrophysics. Supplement Series (1990), 84

This paper presents new data sets of Stromgren differential photometry observations of the Wolf-Rayet star WR16, collected at the ESO (La Silla, Chile). Results of detailed data analyses support previous ... [more ▼]

This paper presents new data sets of Stromgren differential photometry observations of the Wolf-Rayet star WR16, collected at the ESO (La Silla, Chile). Results of detailed data analyses support previous findings concerning the variability of WR16, with dominating power at frequencies below 1.5/d. The variations were found to be positively correlated on time lags up to about two days, a characteristic delay larger than the time of replacement of a typical WR star wind. A simple stochastic model is developed for the low frequency variability of the star, which is able to explain the available observations. [less ▲]

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See detailA search for quasars in a field around NGC 520
Gosset, Eric ULg; Clowes, R. G.; Surdej, Jean ULg et al

in Monthly Notices of the Royal Astronomical Society (1990), 245

An objective-prism search for quasars was performed in a field around the galaxy NGC 520. The automated quasar detection software has been applied, and a sample of 175 highly rated quasar candidates has ... [more ▼]

An objective-prism search for quasars was performed in a field around the galaxy NGC 520. The automated quasar detection software has been applied, and a sample of 175 highly rated quasar candidates has been selected. The two- and three-dimensional distributions of the candidates have been analyzed. The distribution on the celestial sphere turns out to be nonrandom. The deviations from randomness are both a tendency to exhibit anticorrelation at the scale of a few arcmin and a significant excess of objects at separations of about 20 arcmin. Finally, in order to test the claims by Arp and Duhalde (1985) that an excess of quasars exists near NGC 520 and that there is a preferential NE-SW alignment of bright quasars across this amorphous galaxy, various statistical analyses of the distribution of the high-grade quasar candidates with respect to NGC 520 were performed. No sign of any possible relation is present in the data. [less ▲]

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See detailThe possible biperiodicity of WR 40
Gosset, Eric ULg; Vreux, Jean-Marie ULg

in Astronomy and Astrophysics (1990), 231

Strong arguments are presented in favor of the simultaneous presence of two periodicities in the variability of the Wolf-Rayet star WR 40. The frequencies are nu(A) = 0.16/d and nu(B) = 0.40/d. Some ... [more ▼]

Strong arguments are presented in favor of the simultaneous presence of two periodicities in the variability of the Wolf-Rayet star WR 40. The frequencies are nu(A) = 0.16/d and nu(B) = 0.40/d. Some uncertainties remain concerning the choice of the actual one-year alias. On the basis of a detailed statistical analysis, reliable evidence that the variability related to nu(B) could be coherent is also presented: this points out nu(B) as a possible fundamental frequency linked to the 'core' of WR 40. No firm conclusion could be drawn about nu(A), suggesting that it could be a recurrent quasi-periodicity or a second order periodicity (e.g., a beat frequency). The two frequencies are sometimes hidden by the white noise, or slightly correlated, random process that constitutes the third component of the variability of WR 40. [less ▲]

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See detailAnalysis of the photometric variability of WR40
Gosset, Eric ULg; Vreux, Jean-Marie ULg; Manfroid, Jean ULg et al

in Monthly Notices of the Royal Astronomical Society (1989), 238

New photometric data on the star WR40 are presented and, together with data already published, are analyzed in a detailed and homogeneous manner in order to investigate the variability of the star. Good ... [more ▼]

New photometric data on the star WR40 are presented and, together with data already published, are analyzed in a detailed and homogeneous manner in order to investigate the variability of the star. Good evidence is presented for the existence of a periodicity P = 6.250 + or - 0.078 day with a semiamplitude of 0.010 mag in the Stromgren b filter. Only part of the 0.1 mag peak-to-peak variation of the star can be explained in this way and other interesting features of the variability are outlined. The physical origin of the periodicity is discussed. [less ▲]

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See detailNew results on the variability of some WN stars
Gosset, Eric ULg; Vreux, Jean-Marie ULg; Manfroid, Jean ULg et al

in Davidson, K.; Moffat, A. F. J.; Lamers, H.J.G.L.M. (Eds.) Physics of Luminous Blue Variables (1989)

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See detailStatistical tests applied to the spatial distribution of quasars in several fields.
Gosset, Eric ULg; Surdej, Jean ULg; Swings, Jean-Pierre ULg

in Osmer, P. S.; Porter, A. C.; Green, R. F. (Eds.) et al Optical surveys for quasars (1988)

The authors discuss the application of different statistical tests to the study of the spatial distribution of quasars. Applications to data sets of optically selected quasars lead to the detection of a ... [more ▼]

The authors discuss the application of different statistical tests to the study of the spatial distribution of quasars. Applications to data sets of optically selected quasars lead to the detection of a clustering at a typical scale of 10 arcmin. Furthermore, the spatial distribution of quasars in a field around NGC 450 shows a deviation from randomness, towards clustering, at a scale of 10 h[SUP]-1[/SUP]Mpc. [less ▲]

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See detailSurveys of Ultraviolet Excess Quasar Candidates in Three Large Fields
Swings, Jean-Pierre ULg; Surdej, Jean ULg; Gosset, Eric ULg

in Osmer, Patric S. (Ed.) Astron. Soc. of the Pac. Conf. Series: Optical Surveys for Quasars (1988)

A general description is given of the surveys performed in the fields around NGC 450 and NGC 520, and in the ESO field No. 300 with the aim of detecting ultraviolet excess quasar candidates.

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See detailA three-dimensional extended Kolmogorov-Smirnov test as a useful tool in astronomy
Gosset, Eric ULg

in Astronomy and Astrophysics (1987), 188

The authors derive a three-dimensional version of the well-known Kolmogorov-Smirnov test. Such a test is of great practical interest when one wishes to investigate the spatial distribution of a set of ... [more ▼]

The authors derive a three-dimensional version of the well-known Kolmogorov-Smirnov test. Such a test is of great practical interest when one wishes to investigate the spatial distribution of a set of data points, particularly for the case of small size samples. A comparison with assumed three-dimensional density laws is made possible for most of current applications. A table of critical values of the new statistic is given for usual significance levels; empirical formulate to simulate the asymptotic behaviour are given as well. The tree-dimensional extended two-sided Kolmogorov-Smirnov test is shown to be sufficiently distribution-free. [less ▲]

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See detailWhich photometric period for WR 16?
Manfroid, Jean ULg; Gosset, Eric ULg; Vreux, Jean-Marie ULg

in Astronomy and Astrophysics (1987), 185

Analysis of new and already published photometric observations shows that the Wolf-Rayet star WR 16 = HD 86161 is not a binary system (WR + compact, P = 5.365 d) as claimed by Moffat and Niemela (1982 ... [more ▼]

Analysis of new and already published photometric observations shows that the Wolf-Rayet star WR 16 = HD 86161 is not a binary system (WR + compact, P = 5.365 d) as claimed by Moffat and Niemela (1982). Instead it is shown that the simultaneous presence of two periodicities (about 1.3 and 2.5 days) is necessary to account for the observed variations during at least one observing run. The variability of the B9p star HD 86199, previously used as a comparison for a photometric study of WR 16, is established. [less ▲]

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See detailThe possible appearance of a second period in the WN 5 star EZ Canis Majoris
Gosset, Eric ULg; Vreux, Jean-Marie ULg

in Astronomy and Astrophysics (1987), 178

Previously published photometric data on EZ Canis Majoris are reanalyzed. It is shown by different techniques that a sine-wave type periodicity close to one third of the claimed period of P = 3[SUP]d[/SUP ... [more ▼]

Previously published photometric data on EZ Canis Majoris are reanalyzed. It is shown by different techniques that a sine-wave type periodicity close to one third of the claimed period of P = 3[SUP]d[/SUP].766 may also be present in what was considered as peculiarities in the lightcurve. The data available do not allow to known if this second period is precisely equal or only close to one third of P nor if there is some dependence between the two. In any case, the mere possible existence of such a second period is an interesting fact in the discussion concerning the possible existence of non-radial pulsations in some WR stars. [less ▲]

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See detailThe ultraviolet spectrum of the peculiar emission-line star GG Carinae
Brandi, E.; Gosset, Eric ULg; Swings, Jean-Pierre ULg

in Astronomy and Astrophysics (1987), 175

This paper presents the first study of the properties of the peculiar emission-line star GG Carinae in the ultraviolet wavelength domain. From IUE high resolution spectra, the authors investigate the ... [more ▼]

This paper presents the first study of the properties of the peculiar emission-line star GG Carinae in the ultraviolet wavelength domain. From IUE high resolution spectra, the authors investigate the behaviour of different velocities. From IUE low resolution data, they propose a value of the B-V excess of E[SUB]B-V[/SUB] = 0.52±0.04 (2σ). The continuum of GG Car from the UV to the visible is rather well represented by the theoretical flux of a T[SUB]eff[/SUB] = 18,000K Kurucz standard model atmosphere. The authors investigate also the ultraviolet light curve, which is essentially similar to the one observed in the visible (Gosset et al., 1984, 1985). [less ▲]

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See detailThe ultraviolet spectrum of the peculiar emission-line star GG Carinae - The line identifications
Brandi, E.; Gosset, Eric ULg

in Astronomy and Astrophysics. Supplement Series (1987), 68

Line features as well as the continuum of GG Carinae in the ultraviolet wavelength domain were described by Brandi et al. (1986) on the basis of a series of high and low resolution IUE spectra for which ... [more ▼]

Line features as well as the continuum of GG Carinae in the ultraviolet wavelength domain were described by Brandi et al. (1986) on the basis of a series of high and low resolution IUE spectra for which the line identifications are detailed here. The present contribution is thus the complement to the above-mentioned paper and enables the disentangling of the complex and rich spectrum of GG Carinae. [less ▲]

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See detailIs There an Alignment of Quasars Near NGC 520?
Gosset, Eric ULg; Surdej, Jean ULg; Swings, Jean-Pierre ULg

in Hewitt, Adelaide; Burbidge, Geoffrey; Fang, Li Zhi (Eds.) IAU Symposium, No. 124 "Observational Cosmology" (1987)

Three statistical tests applied to 65 UV excess objects in the field of NGC 520 lead to no detection of any significant alignment.

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