References of "Jorissen, A"
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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 detailMESS (Mass-loss of Evolved StarS), a Herschel Key Program
Groenewegen, M. A. T.; Waelkens, C.; Barlow, M. J. et al

in Astronomy and Astrophysics (2011), 526

MESS (Mass-loss of Evolved StarS) is a Guaranteed Time Key Program that uses the PACS and SPIRE instruments on board the Herschel Space Observatory to observe a representative sample of evolved stars ... [more ▼]

MESS (Mass-loss of Evolved StarS) is a Guaranteed Time Key Program that uses the PACS and SPIRE instruments on board the Herschel Space Observatory to observe a representative sample of evolved stars, that include asymptotic giant branch (AGB) and post-AGB stars, planetary nebulae and red supergiants, as well as luminous blue variables, Wolf-Rayet stars and supernova remnants. In total, of order 150 objects are observed in imaging and about 50 objects in spectroscopy. This paper describes the target selection and target list, and the observing strategy. Key science projects are described, and illustrated using results obtained during Herschel's science demonstration phase. Aperture photometry is given for the 70 AGB and post-AGB stars observed up to October 17, 2010, which constitutes the largest single uniform database of far-IR and sub-mm fluxes for late-type stars. [less ▲]

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See detailResults from the Herschel Key Program MESS
Groenewegen, M. A. T.; Waelkens, C.; Barlow, M. J. et al

in Kerschbaum, F.; Lebzelter, T.; Wing, R. F. (Eds.) Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants. ASPC 445 (2011)

MESS (Mass loss of Evolved StarS) is a Herschel Guaranteed Time Key Program that will image about 100, and do spectroscopy of about 50, post-main-sequence objects of all flavours: AGB stars, post-AGB ... [more ▼]

MESS (Mass loss of Evolved StarS) is a Herschel Guaranteed Time Key Program that will image about 100, and do spectroscopy of about 50, post-main-sequence objects of all flavours: AGB stars, post-AGB stars, planetary nebulae, luminous blue variables, Wolf-Rayet stars, and supernova remnants. In this review the implementation and current status of MESS is outlined, and first results are presented. [less ▲]

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See detailTransition probabilities in singly ionized promethium and the identification of PmII lines in Przybylski's star and HR 465
Fivet, V.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Monthly Notices of the Royal Astronomical Society (2007), 380(2), 771-780

The first theoretical transition probabilities are obtained for a set of 46 Pm ii transitions of astrophysical interest. These data fill in a gap in astrophysics and will allow to establish, on a firmer ... [more ▼]

The first theoretical transition probabilities are obtained for a set of 46 Pm ii transitions of astrophysical interest. These data fill in a gap in astrophysics and will allow to establish, on a firmer basis, the presence of some lines of this radioactive element in the spectra of chemically peculiar stars and, consequently, a quantitative investigation of the stellar Pm abundance. A search for Pm ii lines in Przybylski's star (HD 101065) and in HR 465 is reported and discussed, supporting the detection of this ion. A more detailed quantitative analysis is awaiting the availability of dedicated model atmospheres for these stars. [less ▲]

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See detailProper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data
Frankowski, A.; Jancart, Sylvie ULg; Jorissen, A.

in Astronomy and Astrophysics (2007), 464

Context: This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue. <BR />Aims: The comparison of the proper motions constructed from positions spanning a ... [more ▼]

Context: This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue. <BR />Aims: The comparison of the proper motions constructed from positions spanning a short (Hipparcos) or long time (Tycho-2) makes it possible to uncover binaries with periods of the order of or somewhat larger than the short time span (in this case, the 3 yr duration of the Hipparcos mission), since the unrecognised orbital motion will then add to the proper motion. <BR />Methods: A list of candidate proper motion binaries is constructed from a carefully designed χ[SUP]2[/SUP] test evaluating the statistical significance of the difference between the Tycho-2 and Hipparcos proper motions for 103 134 stars in common between the two catalogues (excluding components of visual systems). Since similar lists of proper-motion binaries have already been constructed, the present paper focuses on the evaluation of the detection efficiency of proper-motion binaries, using different kinds of control data (mostly radial velocities). The detection rate for entries from the Ninth Catalogue of Spectroscopic Binary Orbits (S_B^9) is evaluated, as well as for stars like barium stars, which are known to be all binaries, and finally for spectroscopic binaries identified from radial velocity data in the Geneva-Copenhagen survey of F and G dwarfs in the solar neighbourhood. <BR />Results: Proper motion binaries are efficiently detected for systems with parallaxes in excess of ~20 mas, and periods in the range 1000-30 000 d. The shortest periods in this range (1000-2000 d, i.e., once to twice the duration of the Hipparcos mission) may appear only as DMSA/G binaries (accelerated proper motion in the Hipparcos Double and Multiple System Annex). Proper motion binaries detected among S_B[SUP]9[/SUP] systems having periods shorter than about 400 d hint at triple systems, the proper-motion binary involving a component with a longer orbital period. A list of 19 candidate triple systems is provided. Binaries suspected of having low-mass (brown-dwarf-like) companions are listed as well. Among the 37 barium stars with parallaxes larger than 5 mas, only 7 exhibit no evidence for duplicity whatsoever (be it spectroscopic or astrometric). Finally, the fraction of proper-motion binaries shows no significant variation among the various (regular) spectral classes, when due account is taken for the detection biases. Full Table [see full text] is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/464/377 [less ▲]

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See detailRadiative decay of the 4d(5)(S-6)5p z(5,7)P(o) states in TcII: comparison along the homologous and isoelectronic sequences. Application to astrophysics
Palmeri, P.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Monthly Notices of the Royal Astronomical Society (2007), 374(1), 63-71

Using three independent theoretical approaches (CA, HFR+CP, AUTOSTRUCTURE), oscillator strengths have been calculated for a set of Tc II transitions of astrophysical interest and the reliability of their ... [more ▼]

Using three independent theoretical approaches (CA, HFR+CP, AUTOSTRUCTURE), oscillator strengths have been calculated for a set of Tc II transitions of astrophysical interest and the reliability of their absolute scale has been assessed. The examination of the spectra emitted by some Ap stars has allowed the identification of Tc II transitions in HD 125248. This Tc II detection should however await confirmation from spectral synthesis relying on dedicated model atmospheres. New partition functions are also provided for Tc I, TcII and Tc III for temperatures ranging between 4000 and 13 000 K. [less ▲]

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See detailTransition probabilities and lifetimes in neutral and singly ionized osmium and the Solar osmium abundance
Quinet, Pascal ULg; Palmeri, P.; Biémont, Emile ULg et al

in Astronomy and Astrophysics (2006), 448(3), 1207-93

Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 12 levels of Os I and for 9 levels of Os II. For 9 levels of Os I and 4 levels of Os II ... [more ▼]

Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 12 levels of Os I and for 9 levels of Os II. For 9 levels of Os I and 4 levels of Os II, there were no previous experimental data available. From a comparison with new theoretical calculations, taking configuration interactions and core-polarization effects into account, it has been possible to deduce oscillator strengths for 129 transitions of Os I and 137 transitions of Os II of astrophysical interest appearing in the wavelength range 180.0-870.0 nm. These results have allowed us to revise the abundance of osmium in the solar photosphere (log epsilon(Os) = 1.25 +/- 0.11). The newly derived oscillator strengths have been applied as well to derive the osmium abundance in the carbon-rich metal-poor star HD 187861. [less ▲]

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See detailAstrometric orbits of SB^9 stars
Jancart, Sylvie ULg; Jorissen, A.; Babusiaux, C. et al

in Astronomy and Astrophysics (2005), 442

Hipparcos Intermediate Astrometric Data (IAD) have been used to derive astrometric orbital elements for spectroscopic binaries from the newly released Ninth Catalogue of Spectroscopic Binary Orbits (S[SUB ... [more ▼]

Hipparcos Intermediate Astrometric Data (IAD) have been used to derive astrometric orbital elements for spectroscopic binaries from the newly released Ninth Catalogue of Spectroscopic Binary Orbits (S[SUB]B^9[/SUB]). This endeavour is justified by the fact that (i) the astrometric orbital motion is often difficult to detect without the prior knowledge of the spectroscopic orbital elements, and (ii) such knowledge was not available at the time of the construction of the Hipparcos Catalogue for the spectroscopic binaries which were recently added to the S[SUB]B^9[/SUB] catalogue. Among the 1374 binaries from S[SUB]B^9[/SUB] which have an HIP entry (excluding binaries with visual companions, or DMSA/C in the Double and Multiple Stars Annex), 282 have detectable orbital astrometric motion (at the 5% significance level). Among those, only 70 have astrometric orbital elements that are reliably determined (according to specific statistical tests), and for the first time for 20 systems. This represents a 8.5% increase of the number of astrometric systems with known orbital elements (The Double and Multiple Systems Annex contains 235 of those DMSA/O systems). The detection of the astrometric orbital motion when the Hipparcos IAD are supplemented by the spectroscopic orbital elements is close to 100% for binaries with only one visible component, provided that the period is in the 50-1000 d range and the parallax is >5 mas. This result is an interesting testbed to guide the choice of algorithms and statistical tests to be used in the search for astrometric binaries during the forthcoming ESA Gaia mission. Finally, orbital inclinations provided by the present analysis have been used to derive several astrophysical quantities. For instance, 29 among the 70 systems with reliable astrometric orbital elements involve main sequence stars for which the companion mass could be derived. Some interesting conclusions may be drawn from this new set of stellar masses, like the enigmatic nature of the companion to the Hyades F dwarf HIP 20935. This system has a mass ratio of 0.98 but the companion remains elusive. [less ▲]

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See detailHipparcos Astrometric Binaries in the Ninth Catalogue of Spectroscopic Binary Orbits: A Testbench for the Detection of Astrometric Binaries with Gaia
Jancart, Sylvie ULg; Jorissen, A.; Pourbaix, D.

in O'Flaherty, K.S.; Perryman, M.A.C (Eds.) The Three-Dimensional Universe with Gaia (2005, January 01)

The Ninth Catalogue of Spectroscopic Binary Orbits1 and the Hipparcos Intermediate Astrometric Data (IAD) are used to retrieve astrometric binaries from the Hipparcos data. It is found that basically all ... [more ▼]

The Ninth Catalogue of Spectroscopic Binary Orbits1 and the Hipparcos Intermediate Astrometric Data (IAD) are used to retrieve astrometric binaries from the Hipparcos data. It is found that basically all (non-SB2) systems with periods larger than about 100 d, and parallaxes larger than 5-10 mas exhibit an astrometric orbital motion which can be extracted from the IAD. The lessons learned from this kind of approach will be very valuable for the design of the Gaia reduction pipeline. [less ▲]

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See detailBinaries in the Hipparcos data: Keep digging, I. Search for binaries without `a priori' knowledge of their orbital elements: Application to barium stars
Jorissen, A.; Jancart, Sylvie ULg; Pourbaix, D.

in Hensberge, H; Pavlovski, K.; Hilditch, R.W. (Eds.) Spectroscopically and Spatially Resolving the Components of the Close Binary Stars (2004, December 01)

This work makes use of Hipparcos data to test the algorithms of (i) binary detection and (ii) orbital-parameters determination, which could possibly be used in the GAIA pipeline. The first item is ... [more ▼]

This work makes use of Hipparcos data to test the algorithms of (i) binary detection and (ii) orbital-parameters determination, which could possibly be used in the GAIA pipeline. The first item is addressed in this paper, whereas the second one is addressed in a companion paper by Pourbaix, Jancart, & Jorissen (2004, this volume). Here we test the ability of the algorithm to detect binaries from scratch, i.e., from the astrometric data without any a priori knowledge of the orbital elements. The Hipparcos Intermediate Astrometric Data of a complete sample of 163 barium stars (supposed to be all members of binary systems from theoretical considerations) are used as a test bench. When \varpi > 5 mas and P < 4000 d, the binary detection rate is close to 100%, but it falls to 22% when considering the whole sample, because many barium stars have small parallaxes or very long periods. [less ▲]

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See detailBinaries in the Hipparcos data: keep digging II. Modeling the IAD of known spectroscopic systems
Pourbaix, D.; Jancart, Sylvie ULg; Jorissen, A.

in Hensberge, H.; Pavlovski, K.; Hilditch, R. W. (Eds.) Spectroscopically and Spatially Resolving the Components of the Close Binary Stars (2004, December 01)

We reprocess the Hipparcos Intermediate Astrometric Data of know spectroscopic binaries (retrived from the 9th catalogue of spectroscopic binary orbits, http://sb9.astro.ulb.ac.be) to see whether the ... [more ▼]

We reprocess the Hipparcos Intermediate Astrometric Data of know spectroscopic binaries (retrived from the 9th catalogue of spectroscopic binary orbits, http://sb9.astro.ulb.ac.be) to see whether the orbital inclination, and thus the mass of the secondary, can be derived. Several statistical tests (Pourbaix & Arenou 2001) are used to ensure the reliability of the fit. About 70 systems (originally processed as single stars) out of 863 benefit from the orbital model. [less ▲]

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See detailAccretion of Gas by Globular Cluster Stars
Thoul, Anne ULg; Jehin, Emmanuel ULg; Magain, Pierre ULg et al

in Piotto, G.; Meylan, M.; Djorgovski, G. (Eds.) et al New Horizons in Globular Cluster Astronomy (2003)

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See detailAccretion processes onto globular cluster stars
Thoul, Anne ULg; Jorissen, A.; Goriely, S. et al

in Noels-Grötsch, Arlette; Magain, Pierre; Caro, Denise (Eds.) et al Liege International Astrophysical Colloquia (2000)

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See detailAccretion from AGB winds.
Thoul, Anne ULg; Jorissen, A.; Goriely, S. et al

in Memorie della Società Astronomica Italiana : Journal of the Italian Astronomical Society (2000), 71

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See detailThe onset of photometric variability in red giant stars.
Jorissen, A.; Mowlavi, N.; Sterken, C. et al

in Astronomy and Astrophysics (1997), 324

The onset of variability in red giant stars is studied from the data collected by the `Long-Term Photometry of Variables' project which operates at ESO (La Silla) since 1982. The differential nature of ... [more ▼]

The onset of variability in red giant stars is studied from the data collected by the `Long-Term Photometry of Variables' project which operates at ESO (La Silla) since 1982. The differential nature of the observations combined with a multi-night reduction algorithm enables to study the variability of over 50 red giants with an accuracy of the order of 2 to 3 millimagnitudes on time scales ranging from days to years. All red giants with spectral types late G to early K (i.e. b-y~0.6-0.8) are stable at the level Ï _y_<6millimag (where Ï _y_ is the standard deviation of the Stroemgren y magnitude). Red giants with later spectral types are all variable, and it is found that the minimum variability level Ï _y, min_ increases with increasing b-y, thus defining a minimum-variability boundary. The new data obtained in this paper reveal that the time scale of the associated variability increases with increasing b-y (and thus amplitude), and that the stability of this time scale improves concomitantly. More precisely, irregular variations on time scales of 5 to 10-days (and Ï _y_~7millimag) characterize red giants with b-y~1.0, whereas the variations (with Ï _y_~100millimag) become more regular with periods of the order of 50d for red giants with b-y~1.3. A radial-velocity jitter (of the order of 1.5km/s r.m.s.) is associated with this photometric variability, and suggests that stellar oscillations may be responsible for the observed variations. [less ▲]

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See detailLong-term photometry of Variables IV (Sterken+, 1995)
Sterken, C.; Manfroid, Jean ULg; Beele, D. et al

Report (1996)

This is the fourth catalogue of photometric data in the Stroemgren system obtained during the period June 18, 1992 - August 23, 1994 in the framework of the Long-Term Photometry of Variables (LTPV ... [more ▼]

This is the fourth catalogue of photometric data in the Stroemgren system obtained during the period June 18, 1992 - August 23, 1994 in the framework of the Long-Term Photometry of Variables (LTPV) program at the European Southern Observatory. 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 3 of paper) ------------------------------ y b-y m1 c1 ------------------------------ 0.005 0.002 0.004 0.007 ------------------------------ (2 data files). [less ▲]

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See detailLong-term photometry of Variables III (Manfroid+, 1995)
Manfroid, Jean ULg; Sterken, C.; Cunow, B. et al

Report (1995)

This is the third catalogue of photometric data in the Stroemgren system obtained during the period October 1990-January 1992 in the framework of the Long-Term Photometry of Variables (LTPV) program at ... [more ▼]

This is the third catalogue of photometric data in the Stroemgren system obtained during the period October 1990-January 1992 in the framework of the Long-Term Photometry of Variables (LTPV) program at the European Southern Observatory. All data have been obtained with the Danish 50-cm telescope. The mean values of the r.m.s. deviations of the differential measurements of comparison stars are around (from Table 4 of paper) ------------------------------ y b-y m1 c1 ------------------------------ 0.005 0.002 0.004 0.006 ------------------------------ (2 data files). [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 detailLong-term photometry of variables at ESO. IV. The fourth data catalogue (1992-1994).
Sterken, C.; Manfroid, Jean ULg; Beele, D. et al

in Astronomy and Astrophysics. Supplement Series (1995), 113

In this paper we present the fourth catalogue of photometric data in the Stroemgren system obtained during the period June 18, 1992-August 23, 1994 in the framework of the Long-Term Photometry of ... [more ▼]

In this paper we present the fourth catalogue of photometric data in the Stroemgren system obtained during the period June 18, 1992-August 23, 1994 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 Donnees de Strasbourg via anonymous ftp 130.79.128.5. [less ▲]

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