André-Nicolas Chené

New Galactic star clusters discovered in the VVV survey

Context. VISTA Variables in the V´oa Lactea (VVV) is one of the six ESO Public Surveys operating on the new 4-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV is scanning the Milky Way bulge and an adjacent section of the disk, where star formation activity is high. One of the principal goals of the VVV Survey is to find new star clusters of different ages. Aims. In order to trace the early epochs of star cluster formation we concentrated our search in the directions to those of known star formation regions, masers, radio, and infrared sources. Methods. The disk area covered by VVV was visually inspected using the pipeline processed and calibrated KS-band tile images for stellar overdensities. Subsequently, we examined the composite JHKS and ZJKS color images of each candidate. PSF photometry of 15 × 15 arcmin fields centered on the candidates was then performed on the Cambridge Astronomy Survey Unit reduced images. After statistical field-star decontamination, color-magnitude and color-color diagrams were constructed and analyzed. Results. We report the discovery of 96 new infrared open clusters and stellar groups. Most of the new cluster candidates are faint and compact (with small angular sizes), highly reddened, and younger than 5Myr. For relatively well populated cluster candidates we derived their fundamental parameters such as reddening, distance, and age by fitting the solar- metallicity Padova isochrones to the color-magnitude diagrams.

DETERMINATION OF THE INCLINATION OF THE MULTI-PLANET HOSTING STAR HR 8799 USING ASTEROSEISMOLOGY*

Direct imaging of the HR8799 system was a major achievement in the study of exoplanets. HR8799 is a

Massive open star clusters using the VVV survey - I. Presentation of the data and description of the approach

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New galactic star clusters discovered in the VVV survey. Candidates projected on the inner disk and bulge

\,Doradus variable and asteroseismology can provide an independent constraint on the inclination. Using 650 high signal-to-noise, high resolution, full visual wavelength spectroscopic observations obtained over two weeks at Observatoire de Haute Provence (OHP) with the SOPHIE spectrograph we find that the main frequency in the radial velocity data is 1.9875 d

MOST detects corotating bright spots on the mid-O-type giant ξ Persei

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Very Massive Stars in the local Universe

. This frequency corresponds to the main frequency as found in previous photometric observations. Using the FAMIAS software to identify the pulsation modes, we find this frequency is a prograde

NEW EVIDENCE SUPPORTING MEMBERSHIP FOR TW NOR IN LYNGA 6 AND THE CENTAURUS SPIRAL ARM

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WR 110: a single Wolf–Rayet star with corotating interaction regions in its wind?

=1 sectoral mode and obtain the constraint that inclination

Two massive stars possibly ejected from NGC 3603 via a three-body encounter

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Discovery of new companions to high proper motion stars from the VVV Survey

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