References of "Hensberge, H"
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See detailA search for pulsations in the HgMn star HD 45975 with CoRoT photometry and ground-based spectroscopy
Morel, Thierry ULg; Briquet, Maryline ULg; Auvergne, M. et al

in Astronomy and Astrophysics (2014), 561

The existence of pulsations in HgMn stars is still being debated. To provide the first unambiguous observational detection of pulsations in this class of chemically peculiar objects, the bright star HD ... [more ▼]

The existence of pulsations in HgMn stars is still being debated. To provide the first unambiguous observational detection of pulsations in this class of chemically peculiar objects, the bright star HD 45975 was monitored for nearly two months by the CoRoT satellite. Independent analyses of the light curve provide evidence of monoperiodic variations with a frequency of 0.7572 d[SUP]-1[/SUP] and a peak-to-peak amplitude of ~2800 ppm. Multisite, ground-based spectroscopic observations overlapping the CoRoT observations show the star to be a long-period, single-lined binary. Furthermore, with the notable exception of mercury, they reveal the same periodicity as in photometry in the line moments of chemical species exhibiting strong overabundances (e.g., Mn and Y). In contrast, lines of other elements do not show significant variations. As found in otherHgMn stars, the pattern of variability consists in an absorption bump moving redwards across the line profiles. We argue that the photometric and spectroscopic changes are more consistent with an interpretation in terms of rotational modulation of spots at the stellar surface. In this framework, the existence of pulsations producing photometric variations above the ~50 ppm level is unlikely in HD 45975. This provides strong constraints on the excitation/damping of pulsation modes in this HgMn star. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. This work is based on observations collected at La Silla and Paranal Observatories, ESO (Chile), with the HARPS and UVES spectrographs at the 3.6-m and very large telescopes, under programmes LP185.D-0056 and 287.D-5066. It is also based on observations made with the Mercator Telescope, operated on the island of La Palma by the Flemish Community, at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Based on observations obtained with the HERMES spectrograph, which is supported by the Fund for Scientific Research of Flanders (FWO), Belgium, the Research Council of K.U. Leuven, Belgium, the Fonds National de la Recherche Scientifique (FNRS), Belgium, the Royal Observatory of Belgium, the Observatoire de Genève, Switzerland, and the Thüringer Landessternwarte Tautenburg, Germany. [less ▲]

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See detailThe massive binary CPD-41°7742 - I. High-resolution optical spectroscopy
Sana, H.; Hensberge, H.; Rauw, Grégor ULg et al

in Astronomy and Astrophysics (2003), 405(3), 1063-1074

We present the results of a spectroscopic campaign on the early-type binary CPD-41degrees 7742. For the first time, we unambiguously detect the secondary's spectral signature and derive an accurate ... [more ▼]

We present the results of a spectroscopic campaign on the early-type binary CPD-41degrees 7742. For the first time, we unambiguously detect the secondary's spectral signature and derive an accurate orbital solution for both components of the system. We confirm that the orbit displays a slight but definite eccentricity (e=0.027+/-0.006) despite the short period (P=2.44070+/-0.00043 days). Previous radial velocity measurements available in the literature constitute together with our new observations a data set that spans more than 30 years. The combined primary orbital solution inferred is in excellent agreement with our solution and gives a period P=2.44062+/-0.00005 days. Based on spectroscopic criteria, we derive a spectral and luminosity classification of O9 III + B1 III. However, the luminosities and radii inferred from the membership of NGC6231 rather indicate lower luminosity classes. We show that the equivalent widths of well isolated primary lines display variations that suggest that CPD-41degrees 7742 is an eclipsing binary. This makes CPD-41degrees 7742 the second known SB2 eclipsing early-type binary of the NGC 6231 cluster. We approximately constrain the inclination of the system i(min) approximate to 60degrees. This may indicate that the system does not offer enough room for two stars with radii typical of giant stars and lends further support to a less evolved luminosity classification for at least one of the objects. [less ▲]

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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 detailLongterm Photometry of Variables at ESO - Part Two - the Second Data Catalogue 1986-1990
Sterken, C.; Manfroid, Jean ULg; Anton, K. et al

in Astronomy and Astrophysics. Supplement Series (1993), 102

In this paper we present the second catalogue of photometric data in the Strömgren system obtained during the period October 1986- September 1990 in the framework of the Long-Term Photometry of Variables ... [more ▼]

In this paper we present the second catalogue of photometric data in the Strömgren system obtained during the period October 1986- September 1990 in the framework of the Long-Term Photometry of Variables (LTPV) program at the European Southern Observatory. The catalogue is available in computer readable form at the Centre de Données de Strasbourg. [less ▲]

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See detailLong-Term Photometry of Variables at ESO. II. The Second Data Catalogue (1986-1990).
Sterken, C.; Manfroid, Jean ULg; Anton, K. et al

in European Southern Observatory Scientific Report (1993), 12

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See detailLong-term stability of classical photometry
Hensberge, H.; Manfroid, Jean ULg; Sterken, C.

in The Messenger (1992), 70

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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)

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See detailThe European working group on chemically peculiar stars of the upper main sequence. The first 10 years.
Mathys, G.; Maitzen, H. M.; North, P. et al

in The Messenger (1989), 55

A fraction of the Band A type stars have chemical peculiarities (CP). 4 subgroups are recognized: CP 1 or Am, CP2 or magnetic Ap (with enhanced Sr, Cr, Eu, Si lines), CP3 (ar non-magnetic Ap, with Hg Mn ... [more ▼]

A fraction of the Band A type stars have chemical peculiarities (CP). 4 subgroups are recognized: CP 1 or Am, CP2 or magnetic Ap (with enhanced Sr, Cr, Eu, Si lines), CP3 (ar non-magnetic Ap, with Hg Mn enhanced) and CP4 (B type stars with He peculiarities, a fraction of them appear to be a hot extension of CP 2). [less ▲]

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See detailBW Vulpeculae - A coordinated campaign of photoelectric photometry from thirteen observatories
Sterken, C.; Snowden, M.; Africano, J. et al

in Astronomy and Astrophysics. Supplement Series (1986), 66

This paper contains the fully reduced observational data on the Beta Cep star BW Vul, which were obtained in the summer of 1982 during an international campaign at thirteen observatories in the northern ... [more ▼]

This paper contains the fully reduced observational data on the Beta Cep star BW Vul, which were obtained in the summer of 1982 during an international campaign at thirteen observatories in the northern hemisphere. Useful measurements were made during a total of 486 hours. All observations have been assigned proper weights and were binned in time intervals of 90 seconds. In this manner the observations were combined into single data points which resulted in about 6000 mean differential measurements. A preliminary ephemeris for 1982 is derived, and a mean lightcurve is given. The results indicate a fair degree of stability in the shape and in the amplitude of the lightcurve. Possible variations exist in the morphology of the stillstand phenomenon. [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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See detailThe frequency of Ap-stars with long rotation periods
Hensberge, H.; Manfroid, Jean ULg; Renson, Pierre ULg et al

in Astronomy and Astrophysics (1984), 132

Light variability was observed over time intervals of months to years in the stars HD 55540, HD 71066, HD 94660, and HD 187474. The significance of these results is discussed in terms of the frequency of ... [more ▼]

Light variability was observed over time intervals of months to years in the stars HD 55540, HD 71066, HD 94660, and HD 187474. The significance of these results is discussed in terms of the frequency of chemically peculiar CP2 stars showing (light) variability with periods longer than one month. This frequency, relative to the whole CP2 population, must lie somewhere between 4 and 16 percent. Observations, properly distributed in time, of a small subgroup of CP2 stars will be sufficient to obtain an accurate ratio of the number of LP-CP2 stars to the total number of CP2 stars. These observations, when continued until the periodicity is detected, could contribute also to the discussion whether these long periods should be identified with the rotation period. [less ▲]

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See detailThe international photometric observing campaign on BW Vul: first results.
Sterken, C.; Snowden, M.; Young, A. et al

in Theoretical Problems in Stellar Stability and Oscillations (1984)

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See detailThe International Photometric Observing Campaign on BW VUL : First Results
Sterken, C.; Snowden, M.; Young, A. et al

in Liege International Astrophysical Colloquia (1984)

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See detailA photoelectric investigation of light variability in Ap stars
Hensberge, H.; Deridder, G.; Doom, C. et al

in Astronomy and Astrophysics. Supplement Series (1981), 46

A study of the light variability of a number of peculiar A stars, mainly in Stromgren colors u and v and in peculiarity index Delta-a, leads to the proposal of the following light variability periods: (1 ... [more ▼]

A study of the light variability of a number of peculiar A stars, mainly in Stromgren colors u and v and in peculiarity index Delta-a, leads to the proposal of the following light variability periods: (1) HD 5601, 1.11 days; (2) HD 19712, 2.19 days; (3) HD 30849, 15.86 days; (4) HD 38823, 8.64 days; (5) HD 53116, 11.98 or 18.10 days; (6) HD 56022, 0.92 days; and (7) HD 81009, 33.97 days. In addition, evidence is given for variability of HD 94660 on a time scale on the order of months or years, and it is shown that the rotation period proposed by Borra and Landstreet (1980) for HD 25267 is not supported by the light variations observed. The character of Delta-a variability is discussed. [less ▲]

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