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See detailHD 174884: a strongly eccentric, short-period early-type binary system discovered by CoRoT
Maceroni, C.; Montalban Iglesias, Josefa ULg; Michel, E. et al

in Astronomy and Astrophysics (2009), 508

Accurate photometric CoRoT space observations of a secondary seismological target, HD 174884, led to the discovery that this star is an astrophysically important double-lined eclipsing spectroscopic ... [more ▼]

Accurate photometric CoRoT space observations of a secondary seismological target, HD 174884, led to the discovery that this star is an astrophysically important double-lined eclipsing spectroscopic binary in an eccentric orbit (eË 0.3), unusual for its short 3.65705° orbital period. The high eccentricity, coupled with the orientation of the binary orbit in space, explains the very unusual observed light curve with strongly unequal primary and secondary eclipses having the depth ratio of 1-to-100 in the CoRoT â seismoâ passband. Without the high accuracy of the CoRoT photometry, the secondary eclipse, 1.5 mmag deep, would have gone unnoticed. A spectroscopic follow-up program provided 45 high dispersion spectra. The analysis of the CoRoT light curve was performed with an adapted version of PHOEBE that supports CoRoT passbands. The final solution was obtained by a simultaneous fitting of the light and the radial velocity curves. Individual star spectra were obtained by spectrum disentangling. The uncertainties of the fit were achieved by bootstrap resampling and the solution uniqueness was tested by heuristic scanning. The results provide a consistent picture of the system composed of two late B stars. The Fourier analysis of the light curve fit residuals yields two components, with orbital frequency multiples and an amplitude of ~0.1 mmag, which are tentatively interpreted as tidally induced pulsations. An extensive comparison with theoretical models is carried out by means of the Levenberg-Marquardt minimization technique, and the discrepancy between the models and the derived parameters is discussed. The best fitting models yield a young system age of 125 million years which is consistent with the eccentric orbit and synchronous component rotation at periastron. Based on photometry collected by the CoRoT space mission and spectroscopy obtained with the CORALIE spectrograph attached to the 1.2 m Euler telescope at ESO, La Silla, Chile. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programs, Austria, Belgium, Brazil, Germany and Spain. Postdoctoral fellow of the Fund for Scientific Research of Flanders (FWO). [less ▲]

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See detailHD 192163 variability revisited - A very short period WR binary or a pulsating star?
Vreux, Jean-Marie ULg; Andrillat, Y.; Gosset, Eric ULg

in Astronomy and Astrophysics (1985), 149

The present reexamination of emission line variations in HD 192163 on the basis of 23 spectra takes into account stratification effects in the atmosphere of the WR stars, as well as the necessity for a ... [more ▼]

The present reexamination of emission line variations in HD 192163 on the basis of 23 spectra takes into account stratification effects in the atmosphere of the WR stars, as well as the necessity for a high N/R ratio. Because of the peculiar shape of the profiles, the wavelength shifts are measured by comparing the position of every observation to a nearly noise-free profile that is taken as reference. The most probable period supported by the present data is either 0.45 or 0.31 days; these two periods are one-day aliases of each other. [less ▲]

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See detailHD 203608, a quiet asteroseismic target in the old galactic disk
Mosser, B.; Deheuvels, S.; Michel, Eric et al

in Astronomy and Astrophysics (2008), 488

Context: We conducted a 5-night observing run with the spectrometer harps at the ESO 3.6-m telescope in August 2006, to continue exploring the asteroseismic properties of F-type stars. In fact, Doppler ... [more ▼]

Context: We conducted a 5-night observing run with the spectrometer harps at the ESO 3.6-m telescope in August 2006, to continue exploring the asteroseismic properties of F-type stars. In fact, Doppler observations of F-type on the main sequence are demanding and remain currently limited to a single case (HD 49933). Comparison with photometric results obtained with the CoRoT space mission (Convection, Rotation and planetary Transits) on similar stars will be possible with an enhanced set of observations. Aims: We selected the 4th magnitude F8V star HD 203608 to investigate the oscillating properties of a low-metallicity star of the old galactic disk. Methods: We reduced the spectra with the on-line data reduction software provided by the instrument. We developed a new statistical approach for extracting the significant peaks in the Fourier domain. Results: The oscillation spectrum shows a significant excess power in the frequency range [1.5, 3.0 mHz]. It exhibits a large spacing of about 120.4 muHz at 2.5 mHz. Variations of the large spacing with frequency are clearly identified, which require an adapted asymptotic development. The modes identification is based on the unambiguous signature of 15 modes with l = 0 and 1. Conclusions: These observations show the potential diagnostic of asteroseismic constraints. Including them in the stellar modeling significantly enhances the precision on the physical parameters of HD 203608, resulting in a much more precise position in the HR diagram. The age of the star is now determined in the range 7.25±0.07 Gyr. Based on observations obtained with the harps échelle spectrometer mounted on the 3.6-m telescope at ESO-La Silla Observatory (Chile), programme 077.D-0720. Data corresponding to Figs. [see full textsee full textsee full text], [see full textsee full textsee full text], and Table [see full textsee full textsee full text] are 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/488/635 [less ▲]

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See detailHD 259440: The Proposed Optical Counterpart of the γ-ray Binary HESS J0632+057
Aragona, C.; McSwain, M. V.; De Becker, Michaël ULg

in Astrophysical Journal (2010), 724

HD 259440 is a B0pe star that was proposed as the optical counterpart to the γ-ray source HESS J0632+057. Here, we present optical spectra of HD 259440 acquired to investigate the stellar parameters, the ... [more ▼]

HD 259440 is a B0pe star that was proposed as the optical counterpart to the γ-ray source HESS J0632+057. Here, we present optical spectra of HD 259440 acquired to investigate the stellar parameters, the properties of the Be star disk, and evidence of binarity in this system. Emission from the Hα line shows evidence of a spiral density wave in the nearly edge-on disk. We find a best-fit stellar effective temperature of 27,500-30,000 K and a log surface gravity of 3.75-4.0, although our fits are somewhat ambiguous due to scattered light from the circumstellar disk. We derive a mass of 13.2-19.0 M sun and a radius of 6.0-9.6 R sun. By fitting the spectral energy distribution, we find a distance between 1.1 and 1.7 kpc. We do not detect any significant radial velocity shifts in our data, ruling out orbital periods shorter than one month. If HD 259440 is a binary, it is likely a long-period (>100 d) system. [less ▲]

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See detailHD 35155: the First Eclipsing Binary S Star (P=642 Days)
Jorissen, A.; Mayor, M.; Manfroid, Jean ULg et al

in Information Bulletin on Variable Stars (1992), 3730

Not Available

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See detailHD 45314: a new γ Cassiopeiae analog among Oe stars
Rauw, Grégor ULg; Nazé, Yaël ULg; Spano, M. et al

in Astronomy and Astrophysics (2013), 555

Context. Oe stars possibly form an extension to higher temperatures of the Be phenomenon, but it is still unclear whether these stars have disks. <BR /> Aims: X-ray spectra could provide hints for ... [more ▼]

Context. Oe stars possibly form an extension to higher temperatures of the Be phenomenon, but it is still unclear whether these stars have disks. <BR /> Aims: X-ray spectra could provide hints for interactions of the star with a putative surrounding disk. <BR /> Methods: We obtained XMM-Newton observations of two Oe stars, HD 45314 and HD 60848. Spectra and light curves were extracted and analysed. Optical spectra were also obtained to support the X-ray observations. <BR /> Results: We find that both stars display very different X-ray properties. Whilst HD 60848 has an X-ray spectrum and emission level typical for its spectral type, HD 45314 displays a very hard X-ray emission, dominated by a thermal plasma with kT ~ 21 keV. Furthermore, HD 45314 displays count rate variations by a factor 2 on timescales of ~ 10[SUP]3[/SUP] s and a high log (L[SUB]X[/SUB]/L[SUB]bol[/SUB]) = -6.10 ± 0.03. <BR /> Conclusions: The X-ray properties of HD 45314 indicate that this star is a new member of the class of γ Cas analogs, the first one among the original category of Oe stars. Based on observations collected with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA), and observations collected at the European Southern Observatory (La Silla, Chile) and the Observatoire de Haute Provence (France). [less ▲]

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See detailHD 45677 est-elle une étoile variable ?
Swings, Jean-Pierre ULg; Swings, Polydore ULg

in Astronomy and Astrophysics (1972), 17(1), 142-145

Whereas HD 45677 has faded by approximately one magnitude since 1969, the amplitude of variation in photographic magnitude between 1899 and 1969 has always been smaller than 0.3 mag.

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See detailHD 65949: Rosetta Stone or Red Herring
Cowley, C. R.; Hubrig, S.; Palmeri, P. et al

in Monthly Notices of the Royal Astronomical Society (2010), 405

HD 65949 is a late B star with exceptionally strong Hg II λ3984, but it is not a typical HgMn star. The Re II spectrum is of extraordinary strength. Abundances or upper limits are derived here for 58 ... [more ▼]

HD 65949 is a late B star with exceptionally strong Hg II λ3984, but it is not a typical HgMn star. The Re II spectrum is of extraordinary strength. Abundances or upper limits are derived here for 58 elements based on a model with Teff = 13 100K and log(g) = 4.0. Even-Z elements through nickel show minor deviations from solar abundances. Anomalies among the odd-Z elements through copper are mostly small. Beyond the iron peak, a huge scatter is found. Enormous enhancements are found for the elements rhenium through mercury (Z = 75–80). We note the presence of Th III in the spectrum. The abundance pattern of the heaviest elements resembles the N = 126 r-process peak of solar material, though not in detail. An odd-Z anomaly appears at the triplet (Zr Nb Mo), and there is a large abundance jump between Xe (Z = 54) and Ba (Z = 56). These are signatures of chemical fractionation. We find a significant correlation of the abundance excesses with second ionization potentials for elements withZ > 30. If this is not a red herring (false lead), it indicates the relevance of photospheric or near-photospheric processes. Large excesses (4–6 dex) require diffusion from deeper layers with the elements passing through a number of ionization stages. That would make the correlation with second ionization potential puzzling. We explore a model with mass accretion of exotic material followed by the more commonly accepted differentiation by diffusion. That model leads to a number of predictions which challenge future work. New observations confirm the orbital elements of Gieseking and Karimie, apart from the systemic velocity, which has increased. Likely primary and secondary masses are near 3.3 and 1.6 M , with a separation of ca. 0.25 au. New atomic structure calculations are presented in two appendices. These include partition functions for the first through third spectra of Ru, Re and Os, as well as oscillator strengths in the Re II spectrum. [less ▲]

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See detailHD 85037 nouvelle variable à éclipses probable
Renson, Pierre ULg; Heck, A.

in Information Bulletin on Variable Stars (1983), 2298

Not Available

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See detailHD 97658 and its super-Earth. Spitzer & MOST transit analysis and modeling of the host star
Van Grootel, Valérie ULg; Gillon, Michaël ULg; Valencia, D. et al

Conference (2014, July)

Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition ... [more ▼]

Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present here the confirmation, based on Spitzer transit observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a low-mass ($M_*=0.77\pm0.05\,M_{\odot}$) K1 dwarf, as determined from the Hipparcos parallax and stellar evolution modeling. To constrain the planet parameters, we carry out Bayesian global analyses of Keck-HIRES radial velocities, and MOST and Spitzer photometry. HD 97658 b is a massive ($M_P=7.55^{+0.83}_{-0.79} M_{\oplus}$) and large ($R_{P} = 2.247^{+0.098}_{-0.095} R_{\oplus}$ at 4.5 $\mu$m) super-Earth. We investigate the possible internal compositions for HD 97658 b. Our results indicate a large rocky component, by at least 60% by mass, and very little H-He components, at most 2% by mass. We also discuss how future asteroseismic observations can improve the knowledge of the HD 97658 system, in particular by constraining its age. Orbiting a bright host star, HD 97658 b will be a key target for coming space missions TESS, CHEOPS, PLATO, and also JWST, to characterize thoroughly its structure and atmosphere. [less ▲]

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See detailHD 97658 and its super-Earth: Spitzer transit analysis and seismic modeling of the host star
Van Grootel, Valérie ULg; Gillon, Michaël ULg; Valencia, Diana et al

Conference (2013, December)

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

(1992)

Not Available

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See detailHD46407 - the First Eclipsing Binary Barium Star
Jorissen, A.; Manfroid, Jean ULg; Sterken, C.

in Evolutionary Processes in Interacting Binary Stars (1992)

Not Available

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See detailHDA cycloadditions of 1-diethoxyphosphonyl-1,3-butadiene with nitroso heterodienophiles: a computational investigation
Monbaliu, Jean-Christophe ULg; Dive, Georges ULg; Marchand-Brynaert, Jacqueline et al

in Journal of Molecular Structure : Theochem (2010), 959

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See detailThe HDAC inhibitor panobinostat (LBH589) inhibits mesothelioma and lung cancer cells in vitro and in vivo with particular efficacy for small cell lung cancer
Crisanti, Cecilia; Wallace, Africa; Kapoor, Veena et al

in Molecular Cancer Therapeutics (2009), 8(8), 2221-2231

Lung cancer is the leading cause of cancer deaths in the United States. Current therapies are inadequate. Histone deacetylase inhibitors (HDACi) are a recently developed class of anticancer agents that ... [more ▼]

Lung cancer is the leading cause of cancer deaths in the United States. Current therapies are inadequate. Histone deacetylase inhibitors (HDACi) are a recently developed class of anticancer agents that cause increased acetylation of core histones and nonhistone proteins leading to modulation of gene expression and protein activityin - volved in cancer cell growth and survival pathways. We examined the efficacyof the HDACi panobinostat (LBH589) in a wide range of lung cancers and mesotheliomas. Panobinostat was cytotoxic in almost all 37 cancer cell lines tested. IC50 and LD50 values were in the low nmol/L range (4–470 nmol/L; median, 20 nmol/L). Small cell lung cancer (SCLC) cell lines were among the most sensitive lines, with LD50 values consistently <25 nmol/L. In lung cancer and mesothelioma animal models, panobinostat significantlyde creased tumor growth byan average of 62% when compared with vehicle control. Panobinostat was equallye ffective in immunocompetent and severe combined immunodeficiencymic e, indicating that the inhibition of tumor growth by panobinostat was not due to direct immunologic effects.Panobinostat was, however, particularlyeffective in SCLC xenografts, and the addition of the chemotherapyag ent etoposide augmented antitumor effects. Protein analysis of treated tumor biopsies revealed elevated amounts of cell cycle regulators such as p21 and proapoptosis factors, such as caspase 3 and 7 and cleaved poly[ADP-ribose] polymerase, coupled with decreased levels of antiapoptotic factors such as Bcl-2 and Bcl-XL. These studies together suggest that panobinostat maybe a useful adjunct in the treatment of thoracic malignancies, especiallySCLC. [less ▲]

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See detailHDAC4 represses p21(WAF1/Cip1) expression in human cancer cells through a Sp1-dependent, p53-independent mechanism.
Mottet, Denis ULg; Pirotte, Sophie ULg; Lamour, Virginie ULg et al

in Oncogene (2009), 28(2), 243-56

Cancer cells have complex, unique characteristics that distinguish them from normal cells, such as increased growth rates and evasion of anti-proliferative signals. Global inhibition of class I and II ... [more ▼]

Cancer cells have complex, unique characteristics that distinguish them from normal cells, such as increased growth rates and evasion of anti-proliferative signals. Global inhibition of class I and II histone deacetylases (HDACs) stops cancer cell proliferation in vitro and has proven effective against cancer in clinical trials, at least in part, through transcriptional reactivation of the p21(WAF1/Cip1)gene. The HDACs that regulate p21(WAF1/Cip1) are not fully identified. Using small interfering RNAs, we found that HDAC4 participates in the repression of p21(WAF1/Cip1) through Sp1/Sp3-, but not p53-binding sites. HDAC4 interacts with Sp1, binds and reduces histone H3 acetylation at the Sp1/Sp3 binding site-rich p21(WAF1/Cip1) proximal promoter, suggesting a key role for Sp1 in HDAC4-mediated repression of p21(WAF1/Cip1). Induction of p21(WAF1/Cip1) mediated by silencing of HDAC4 arrested cancer cell growth in vitro and inhibited tumor growth in an in vivo human glioblastoma model. Thus, HDAC4 could be a useful target for new anti-cancer therapies based on selective inhibition of specific HDACs. [less ▲]

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See detailHDAC5 depletion modulates heterochromatin plasticity and triggers programmed cell death of human cancer cells
Peixoto, P; Castronovo, V; Matheus, N et al

Poster (2012)

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