Phase-resolved VLT spectroscopy of the bursting low-mass X-ray binaries 4U 1636-536/V801 Ara and 4U 1735-444/V926 Sco is presented. Doppler images of the NIII λ4640 Bowen transition reveal compact spots which we attribute to fluorescent emission from the donor star and enable us to define a new set of spectroscopic ephemerides. We measure Kem = 277

Aims: We report the detection of transit timing variations (TTVs) well in excess of one hour in the Kepler multi-planet candidate system KOI 806. This system exhibits transits consistent with three separate planets - a Super-Earth, a Jupiter, and a Saturn - lying very nearly in a 1:2:5 resonance, respectively. Methods: We used the Kepler public

We have studied here for the first time the use of the log(H 0/[N 0]), log (H 0/[S 0]) diagnostic diagram for determining the metallicities and ionization parameters of the H 0 regions in the Local Group. An important advantage of using these lines is their proximity in wavelength, which both simplifies the observations and makes the de-reddening

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It is well known that when measuring electron densities in H II regions locally via emission line ratios the values observed are 100cm-3, but gobal values obtained via emission measure using surface brightness as the observed parameter are ~1cm-3. This difference is attributable to density fluctuations,and traditional models for these is the `

We present non-LTE analyses of four M33 early B supergiant stars and five Galactic counterparts. This is the first time that B supergiants beyond the Magellanic Clouds are analyzed by means of detailed non-LTE techniques. Among the M33 stars, new spectroscopic observations of B38 (ob21-108) are presented and the object is classified as B1 Ia. The